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| author | Lorry Tar Creator <lorry-tar-importer@baserock.org> | 2015-04-08 03:09:47 +0000 |
|---|---|---|
| committer | <> | 2015-05-05 14:37:32 +0000 |
| commit | f2541bb90af059680aa7036f315f052175999355 (patch) | |
| tree | a5b214744b256f07e1dc2bd7273035a7808c659f /libs/optional/doc/html/boost_optional | |
| parent | ed232fdd34968697a68783b3195b1da4226915b5 (diff) | |
| download | boost-tarball-master.tar.gz | |
Imported from /home/lorry/working-area/delta_boost-tarball/boost_1_58_0.tar.bz2.HEADboost_1_58_0master
Diffstat (limited to 'libs/optional/doc/html/boost_optional')
31 files changed, 3301 insertions, 2312 deletions
diff --git a/libs/optional/doc/html/boost_optional/acknowledgements.html b/libs/optional/doc/html/boost_optional/acknowledgements.html index 659795dbb..d025d5075 100644 --- a/libs/optional/doc/html/boost_optional/acknowledgements.html +++ b/libs/optional/doc/html/boost_optional/acknowledgements.html @@ -6,7 +6,7 @@ <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../index.html" title="Boost.Optional"> <link rel="up" href="../index.html" title="Boost.Optional"> -<link rel="prev" href="dependencies_and_portability/optional_reference_binding.html" title="Optional Reference Binding"> +<link rel="prev" href="relnotes.html" title="Release Notes"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> @@ -19,7 +19,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a> +<a accesskey="p" href="relnotes.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> @@ -116,7 +116,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -124,7 +124,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a> +<a accesskey="p" href="relnotes.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/dependencies_and_portability.html b/libs/optional/doc/html/boost_optional/dependencies_and_portability.html index b99d3b1d6..7c3063717 100644 --- a/libs/optional/doc/html/boost_optional/dependencies_and_portability.html +++ b/libs/optional/doc/html/boost_optional/dependencies_and_portability.html @@ -6,7 +6,7 @@ <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../index.html" title="Boost.Optional"> <link rel="up" href="../index.html" title="Boost.Optional"> -<link rel="prev" href="reference/detailed_semantics.html" title="Detailed Semantics"> +<link rel="prev" href="reference/header__boost_optional_hpp_.html" title="Header <boost/optional.hpp>"> <link rel="next" href="dependencies_and_portability/optional_reference_binding.html" title="Optional Reference Binding"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> @@ -20,7 +20,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="reference/detailed_semantics.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="reference/header__boost_optional_hpp_.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> @@ -75,7 +75,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -83,7 +83,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="reference/detailed_semantics.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="reference/header__boost_optional_hpp_.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/dependencies_and_portability/optional_reference_binding.html b/libs/optional/doc/html/boost_optional/dependencies_and_portability/optional_reference_binding.html index b27d9c1f1..bb9f5d6ec 100644 --- a/libs/optional/doc/html/boost_optional/dependencies_and_portability/optional_reference_binding.html +++ b/libs/optional/doc/html/boost_optional/dependencies_and_portability/optional_reference_binding.html @@ -7,7 +7,7 @@ <link rel="home" href="../../index.html" title="Boost.Optional"> <link rel="up" href="../dependencies_and_portability.html" title="Dependencies and Portability"> <link rel="prev" href="../dependencies_and_portability.html" title="Dependencies and Portability"> -<link rel="next" href="../acknowledgements.html" title="Acknowledgements"> +<link rel="next" href="../relnotes.html" title="Release Notes"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> @@ -20,7 +20,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../acknowledgements.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../relnotes.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> @@ -86,7 +86,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -94,7 +94,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../acknowledgements.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../relnotes.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/quick_start.html b/libs/optional/doc/html/boost_optional/quick_start.html index 18ee7c297..d6b1c3964 100644 --- a/libs/optional/doc/html/boost_optional/quick_start.html +++ b/libs/optional/doc/html/boost_optional/quick_start.html @@ -155,7 +155,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/quick_start/bypassing_unnecessary_default_construction.html b/libs/optional/doc/html/boost_optional/quick_start/bypassing_unnecessary_default_construction.html index ed964cf30..1d75a3f5b 100644 --- a/libs/optional/doc/html/boost_optional/quick_start/bypassing_unnecessary_default_construction.html +++ b/libs/optional/doc/html/boost_optional/quick_start/bypassing_unnecessary_default_construction.html @@ -61,7 +61,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/quick_start/optional_automatic_variables.html b/libs/optional/doc/html/boost_optional/quick_start/optional_automatic_variables.html index 8d22f8642..bde643c72 100644 --- a/libs/optional/doc/html/boost_optional/quick_start/optional_automatic_variables.html +++ b/libs/optional/doc/html/boost_optional/quick_start/optional_automatic_variables.html @@ -61,7 +61,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/quick_start/optional_data_members.html b/libs/optional/doc/html/boost_optional/quick_start/optional_data_members.html index abb558914..1a1a3b078 100644 --- a/libs/optional/doc/html/boost_optional/quick_start/optional_data_members.html +++ b/libs/optional/doc/html/boost_optional/quick_start/optional_data_members.html @@ -80,7 +80,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/quick_start/storage_in_containers.html b/libs/optional/doc/html/boost_optional/quick_start/storage_in_containers.html index f13f5a77d..295fcce18 100644 --- a/libs/optional/doc/html/boost_optional/quick_start/storage_in_containers.html +++ b/libs/optional/doc/html/boost_optional/quick_start/storage_in_containers.html @@ -50,7 +50,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/reference/detailed_semantics.html b/libs/optional/doc/html/boost_optional/reference/detailed_semantics.html deleted file mode 100644 index dfbfc871f..000000000 --- a/libs/optional/doc/html/boost_optional/reference/detailed_semantics.html +++ /dev/null @@ -1,2098 +0,0 @@ -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> -<title>Detailed Semantics</title> -<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> -<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> -<link rel="home" href="../../index.html" title="Boost.Optional"> -<link rel="up" href="../../optional/reference.html" title="Reference"> -<link rel="prev" href="../../optional/reference.html" title="Reference"> -<link rel="next" href="../dependencies_and_portability.html" title="Dependencies and Portability"> -</head> -<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> -<table cellpadding="2" width="100%"><tr> -<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> -<td align="center"><a href="../../../../../../index.html">Home</a></td> -<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> -<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> -<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> -<td align="center"><a href="../../../../../../more/index.htm">More</a></td> -</tr></table> -<hr> -<div class="spirit-nav"> -<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="boost_optional.reference.detailed_semantics"></a><a class="link" href="detailed_semantics.html" title="Detailed Semantics">Detailed - Semantics</a> -</h3></div></div></div> -<p> - Because <code class="computeroutput"><span class="identifier">T</span></code> might be of reference - type, in the sequel, those entries whose semantic depends on <code class="computeroutput"><span class="identifier">T</span></code> being of reference type or not will be - distinguished using the following convention: - </p> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code><span class="emphasis"><em>(not - a ref)</em></span><code class="computeroutput"><span class="special">></span></code>, the - description corresponds only to the case where <code class="computeroutput"><span class="identifier">T</span></code> - is not of reference type. - </li> -<li class="listitem"> - If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span></code>, the description corresponds - only to the case where <code class="computeroutput"><span class="identifier">T</span></code> - is of reference type. - </li> -<li class="listitem"> - If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code>, the description is the same for - both cases. - </li> -</ul></div> -<div class="note"><table border="0" summary="Note"> -<tr> -<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td> -<th align="left">Note</th> -</tr> -<tr><td align="left" valign="top"><p> - The following section contains various <code class="computeroutput"><span class="identifier">assert</span><span class="special">()</span></code> which are used only to show the postconditions - as sample code. It is not implied that the type <code class="computeroutput"><span class="identifier">T</span></code> - must support each particular expression but that if the expression is supported, - the implied condition holds. - </p></td></tr> -</table></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<h5> -<a name="boost_optional.reference.detailed_semantics.h0"></a> - <span class="phrase"><a name="boost_optional.reference.detailed_semantics.optional_class_member_functions"></a></span><a class="link" href="detailed_semantics.html#boost_optional.reference.detailed_semantics.optional_class_member_functions">optional - class member functions</a> - </h5> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">optional</span><span class="special">()</span> - <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Default-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">uninitialized</span>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> T's default constructor <span class="underline">is not</span> called. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_none_t"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Constructs an <code class="computeroutput"><span class="identifier">optional</span></code> uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">uninitialized</span>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>'s - default constructor <span class="underline">is not</span> called. - The expression <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> - denotes an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none_t</span></code> - that can be used as the parameter. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">none</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">n</span><span class="special">(</span><span class="identifier">none</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">n</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_copy_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> - is <code class="computeroutput"><span class="keyword">true</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Directly-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> - and its value is a <span class="emphasis"><em>copy</em></span> of <code class="computeroutput"><span class="identifier">v</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">);</span></code> - in that case, this constructor has no effect. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">ref</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Directly-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> - and its value is an instance of an internal type wrapping the reference - <code class="computeroutput"><span class="identifier">ref</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">vref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">vref</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="special">++</span> <span class="identifier">v</span> <span class="special">;</span> <span class="comment">// mutate referee</span> -<span class="identifier">assert</span> <span class="special">(*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span><span class="special">);</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_move_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> - <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> - is <code class="computeroutput"><span class="keyword">true</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Directly-Move-Constructs an - <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> - and its value is move-constructed from <code class="computeroutput"><span class="identifier">v</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> - is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> - <span class="special">);</span></code> in that case, the state of - <code class="computeroutput"><span class="identifier">v</span></code> is determined by exception - safety guarantees for <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span><span class="special">&&)</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v1</span><span class="special">,</span> <span class="identifier">v2</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">v1</span><span class="special">));</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v2</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> - <span class="identifier">ref</span> <span class="special">)</span> - <span class="special">=</span> <span class="keyword">delete</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> This constructor is deleted - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_bool_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="special">::</span><span class="identifier">optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> - <span class="identifier">T</span><span class="special">&</span> - <span class="identifier">v</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - If condition is true, same as: - </li></ul></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="special">::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> - <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - otherwise, same as: - </li></ul></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">()</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="special">::</span><span class="identifier">optional</span><span class="special">()</span></code> - </p></blockquote></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">rhs</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_copy_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> - is <code class="computeroutput"><span class="keyword">true</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If rhs is initialized, - <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is a <span class="emphasis"><em>copy</em></span> of the value - of <code class="computeroutput"><span class="identifier">rhs</span></code>; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If rhs is initialized, <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> - is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">);</span></code> - in that case, this constructor has no effect. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">uninit</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">uninit</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init</span><span class="special">(</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is another reference to the same object - referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; - else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - will refer to the same object (they alias). - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">uninit</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">uninit</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> - -<span class="identifier">T</span> <span class="identifier">v</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">ref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init</span><span class="special">(</span><span class="identifier">ref</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">v</span> <span class="special">=</span> <span class="number">3</span> <span class="special">;</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_move_constructor_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> - <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span></code><span class="emphasis"><em>see below</em></span><code class="computeroutput"><span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> - is <code class="computeroutput"><span class="keyword">true</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Move-constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is move constructed from <code class="computeroutput"><span class="identifier">rhs</span></code>; - else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Remarks:</strong></span> The expression inside <code class="computeroutput"><span class="keyword">noexcept</span></code> is equivalent to <code class="computeroutput"><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="special">&&</span> - <span class="special">)</span></code> is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> - <span class="special">);</span></code> in that case, <code class="computeroutput"><span class="identifier">rhs</span></code> remains initialized and the value - of <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - is determined by exception safety of <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span><span class="special">&&)</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">uninit</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">uninit</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">init</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">uniqye_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">init</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="keyword">nullptr</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init2</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span> <span class="special">&&</span> - <span class="identifier">rhs</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Move-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is another reference to the same object - referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; - else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - will refer to the same object (they alias). - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">uninit</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">uninit</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> - -<span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">v</span><span class="special">(</span><span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">init</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">init</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> - -<span class="special">*</span><span class="identifier">v</span> <span class="special">=</span> <span class="number">3</span> <span class="special">;</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init2</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is a <span class="emphasis"><em>copy</em></span> of the value - of rhs converted to type <code class="computeroutput"><span class="identifier">T</span></code>; - else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> is called if <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, which requires a valid conversion from <code class="computeroutput"><span class="identifier">U</span></code> to <code class="computeroutput"><span class="identifier">T</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">);</span></code> - in that case, this constructor has no effect. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span><span class="number">123.4</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="number">123.4</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span><span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="number">123</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_move_constructor_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> - <span class="identifier">rhs</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Move-constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is move-constructed from <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code> - is called if <code class="computeroutput"><span class="identifier">rhs</span></code> is initialized, - which requires a valid conversion from <code class="computeroutput"><span class="identifier">U</span></code> - to <code class="computeroutput"><span class="identifier">T</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> - <span class="special">);</span></code> in that case, <code class="computeroutput"><span class="identifier">rhs</span></code> remains initialized and the value - of <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - is determined by exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span><span class="number">123.4</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="number">123.4</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">))</span> <span class="special">;</span> -<span class="identifier">assert</span><span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="number">123</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_constructor_factory"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">InPlaceFactory</span><span class="special">></span> - <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">InPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">TypedInPlaceFactory</span><span class="special">></span> - <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">TypedInPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Constructs an <code class="computeroutput"><span class="identifier">optional</span></code> with a value of <code class="computeroutput"><span class="identifier">T</span></code> obtained from the factory. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> - and its value is <span class="emphasis"><em>directly given</em></span> from the factory - <code class="computeroutput"><span class="identifier">f</span></code> (i.e., the value <span class="underline">is not copied</span>). - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever the <code class="computeroutput"><span class="identifier">T</span></code> - constructor called by the factory throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> See <a class="link" href="../tutorial/in_place_factories.html" title="In-Place Factories">In-Place - Factories</a> - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during the call to the <code class="computeroutput"><span class="identifier">T</span></code> - constructor used by the factory; in that case, this constructor has no - effect. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">C</span> <span class="special">{</span> <span class="identifier">C</span> <span class="special">(</span> <span class="keyword">char</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">)</span> <span class="special">;</span> <span class="special">}</span> <span class="special">;</span> - -<span class="identifier">C</span> <span class="identifier">v</span><span class="special">(</span><span class="char">'A'</span><span class="special">,</span><span class="number">123.4</span><span class="special">,</span><span class="string">"hello"</span><span class="special">);</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span> <span class="identifier">in_place</span> <span class="special">(</span><span class="char">'A'</span><span class="special">,</span> <span class="number">123.4</span><span class="special">,</span> <span class="string">"hello"</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// InPlaceFactory used</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span> <span class="identifier">in_place</span><span class="special"><</span><span class="identifier">C</span><span class="special">>(</span><span class="char">'A'</span><span class="special">,</span> <span class="number">123.4</span><span class="special">,</span> <span class="string">"hello"</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// TypedInPlaceFactory used</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_equal_none_t"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized destroys its contained - value. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_equal_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">rhs</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Assigns the value <code class="computeroutput"><span class="identifier">rhs</span></code> to an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and its value is a - <span class="emphasis"><em>copy</em></span> of <code class="computeroutput"><span class="identifier">rhs</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - assignment operator is used, otherwise, its copy-constructor is used. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> In the event of an - exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified - as far as <code class="computeroutput"><span class="identifier">optional</span></code> is - concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s - <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). - If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>copy constructor</em></span> fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> - -<span class="identifier">T</span> <span class="identifier">y</span><span class="special">;</span> -<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">y</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">y</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> - <span class="identifier">rhs</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> (Re)binds the wrapped reference. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and it references - the same object referenced by <code class="computeroutput"><span class="identifier">rhs</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, it is <span class="emphasis"><em>rebound</em></span> - to the new object. See <a class="link" href="../tutorial/rebinding_semantics_for_assignment_of_optional_references.html" title="Rebinding semantics for assignment of optional references">here</a> - for details on this behavior. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">a</span> <span class="special">=</span> <span class="number">1</span> <span class="special">;</span> -<span class="keyword">int</span> <span class="identifier">b</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">ra</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">rb</span> <span class="special">=</span> <span class="identifier">b</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">ra</span><span class="special">)</span> <span class="special">;</span> - -<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">rb</span> <span class="special">;</span> <span class="comment">// binds 'def' to 'b' through 'rb'</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">b</span> <span class="special">)</span> <span class="special">;</span> -<span class="special">*</span><span class="identifier">def</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> <span class="comment">// changes the value of 'b' to a copy of the value of 'a'</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">b</span> <span class="special">==</span> <span class="identifier">a</span> <span class="special">)</span> <span class="special">;</span> -<span class="keyword">int</span> <span class="identifier">c</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> -<span class="keyword">int</span><span class="special">&</span> <span class="identifier">rc</span> <span class="special">=</span> <span class="identifier">c</span> <span class="special">;</span> -<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">rc</span> <span class="special">;</span> <span class="comment">// REBINDS to 'c' through 'rc'</span> -<span class="identifier">c</span> <span class="special">=</span> <span class="number">4</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="number">4</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_move_equal_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">rhs</span> - <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Moves the value <code class="computeroutput"><span class="identifier">rhs</span></code> to an <code class="computeroutput"><span class="identifier">optional</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and its value is moved - from <code class="computeroutput"><span class="identifier">rhs</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> - or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&&)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - move-assignment operator is used, otherwise, its move-constructor is - used. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> In the event of an - exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified - as far as <code class="computeroutput"><span class="identifier">optional</span></code> is - concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s - <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). - If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>move constructor</em></span> fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> - -<span class="identifier">T</span> <span class="identifier">y1</span><span class="special">,</span> <span class="identifier">y2</span><span class="special">,</span> <span class="identifier">yR</span><span class="special">;</span> -<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">y1</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">yR</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">y2</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">yR</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> - <span class="identifier">rhs</span> <span class="special">)</span> - <span class="special">=</span> <span class="keyword">delete</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> This assignment operator is deleted. - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_equal_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">rhs</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - is <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">CopyAssignable</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> - <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "> -<li class="listitem"> - If <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code> no effect, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code>, destroys the contained value - by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>, initializes the contained value - as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code> - with <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>, - otherwise - </li> -<li class="listitem"> - (if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>) assigns <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> to the contained value. - </li> -</ul></div> - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>; - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> If any exception is - thrown, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code> - remains unchanged. If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s copy constructor, no effect. If - an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s - copy assignment, the state of its contained value is as defined by the - exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s - copy assignment. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> - -<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> -<span class="comment">// previous value (copy of 'v') destroyed from within 'opt'.</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> (Re)binds thee wrapped reference. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and it references - the same object referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; otherwise, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized (and references - no object). - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized and so is <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>, - <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is <span class="emphasis"><em>rebound</em></span> to the new object. See <a class="link" href="../tutorial/rebinding_semantics_for_assignment_of_optional_references.html" title="Rebinding semantics for assignment of optional references">here</a> - for details on this behavior. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">a</span> <span class="special">=</span> <span class="number">1</span> <span class="special">;</span> -<span class="keyword">int</span> <span class="identifier">b</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">ra</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">rb</span> <span class="special">=</span> <span class="identifier">b</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">ora</span><span class="special">(</span><span class="identifier">ra</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">orb</span><span class="special">(</span><span class="identifier">rb</span><span class="special">)</span> <span class="special">;</span> - -<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">orb</span> <span class="special">;</span> <span class="comment">// binds 'def' to 'b' through 'rb' wrapped within 'orb'</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">b</span> <span class="special">)</span> <span class="special">;</span> -<span class="special">*</span><span class="identifier">def</span> <span class="special">=</span> <span class="identifier">ora</span> <span class="special">;</span> <span class="comment">// changes the value of 'b' to a copy of the value of 'a'</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">b</span> <span class="special">==</span> <span class="identifier">a</span> <span class="special">)</span> <span class="special">;</span> -<span class="keyword">int</span> <span class="identifier">c</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> -<span class="keyword">int</span><span class="special">&</span> <span class="identifier">rc</span> <span class="special">=</span> <span class="identifier">c</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">orc</span><span class="special">(</span><span class="identifier">rc</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">ora</span> <span class="special">=</span> <span class="identifier">orc</span> <span class="special">;</span> <span class="comment">// REBINDS ora to 'c' through 'rc'</span> -<span class="identifier">c</span> <span class="special">=</span> <span class="number">4</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">ora</span> <span class="special">==</span> <span class="number">4</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_move_equal_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> - <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span></code><span class="emphasis"><em>see below</em></span><code class="computeroutput"><span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> - and <code class="computeroutput"><span class="identifier">MoveAssignable</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> - <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "> -<li class="listitem"> - If <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code> no effect, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code>, destroys the contained value - by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>, initializes the contained value - as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code> - with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code>, - otherwise - </li> -<li class="listitem"> - (if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>) assigns <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> to the contained value. - </li> -</ul></div> - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>; - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Remarks:</strong></span> The expression inside <code class="computeroutput"><span class="keyword">noexcept</span></code> is equivalent to <code class="computeroutput"><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span> <span class="special">&&</span> - <span class="identifier">is_nothrow_move_assignable</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> If any exception is - thrown, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code> - remains unchanged. If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s move constructor, the state of - <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - is determined by the exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s - move constructor. If an exception is thrown during the call to T's move-assignment, - the state of <code class="computeroutput"><span class="special">**</span><span class="keyword">this</span></code> - and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> - is determined by the exception safety guarantee of T's move assignment. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> - -<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&&</span> <span class="identifier">rhs</span> - <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Same as <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> - <span class="special">)</span></code>. - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_equal_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Assigns another convertible - optional to an optional. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is a <span class="emphasis"><em>copy</em></span> of the value - of <code class="computeroutput"><span class="identifier">rhs</span></code> <span class="emphasis"><em>converted</em></span> - to type <code class="computeroutput"><span class="identifier">T</span></code>; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and rhs are initially initialized, - <code class="computeroutput"><span class="identifier">T</span></code>'s <span class="emphasis"><em>assignment - operator</em></span> (from <code class="computeroutput"><span class="identifier">U</span></code>) - is used. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially initialized but <code class="computeroutput"><span class="identifier">rhs</span></code> - is uninitialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>destructor</em></span> is called. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initially uninitialized but rhs - is initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>converting constructor</em></span> (from <code class="computeroutput"><span class="identifier">U</span></code>) - is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> In the event of an - exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified - as far as optional is concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s - <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). - If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s - converting constructor fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt0</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">opt1</span><span class="special">;</span> - -<span class="identifier">opt1</span> <span class="special">=</span> <span class="identifier">opt0</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt1</span> <span class="special">==</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_move_equal_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> <span class="identifier">rhs</span> - <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Move-assigns another convertible - optional to an optional. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> - is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initialized and its value is moved from the value of <code class="computeroutput"><span class="identifier">rhs</span></code>; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code> - or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> - <span class="special">)</span></code> throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> If both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code> - are initially initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>assignment operator</em></span> (from <code class="computeroutput"><span class="identifier">U</span><span class="special">&&</span></code>) is used. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially initialized but <code class="computeroutput"><span class="identifier">rhs</span></code> - is uninitialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>destructor</em></span> is called. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initially uninitialized but <code class="computeroutput"><span class="identifier">rhs</span></code> is initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s - <span class="emphasis"><em>converting constructor</em></span> (from <code class="computeroutput"><span class="identifier">U</span><span class="special">&&</span></code>) is called. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> In the event of an - exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified - as far as optional is concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s - <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). - If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s - converting constructor fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt0</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">opt1</span><span class="special">;</span> - -<span class="identifier">opt1</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">opt0</span><span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt0</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt1</span> <span class="special">)</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt1</span> <span class="special">==</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_emplace"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span><span class="special">...</span> <span class="identifier">Args</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">emplace</span><span class="special">(</span> <span class="identifier">Args</span><span class="special">...&&</span> - <span class="identifier">args</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> The compiler supports rvalue - references and variadic templates. - </li> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized calls <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">=</span> <span class="identifier">none</span></code>. - Then initializes in-place the contained value as if direct-initializing - an object of type <code class="computeroutput"><span class="identifier">T</span></code> with - <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">Args</span><span class="special">>(</span><span class="identifier">args</span><span class="special">)...</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever the selected <code class="computeroutput"><span class="identifier">T</span></code>'s constructor throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - need not be <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> - or <code class="computeroutput"><span class="identifier">MoveAssignable</span></code>. On - compilers that do not support variadic templates, the signature falls - back to single-argument: <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Arg</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">emplace</span><span class="special">(</span><span class="identifier">Arg</span><span class="special">&&</span> <span class="identifier">arg</span><span class="special">)</span></code>. On compilers that do not support rvalue - references, the signature falls back to two overloads: taking <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code> - lvalue reference. - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> If an exception is - thrown during the initialization of <code class="computeroutput"><span class="identifier">T</span></code>, - <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - is <span class="emphasis"><em>uninitialized</em></span>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">;</span> -<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">(</span><span class="number">0</span><span class="special">);</span> <span class="comment">// create in-place using ctor T(int)</span> -<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">();</span> <span class="comment">// destroy previous and default-construct another T</span> -<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> <span class="comment">// destroy and copy-construct in-place (no assignment called)</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_equal_factory"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">InPlaceFactory</span><span class="special">></span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">InPlaceFactory</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">f</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">TypedInPlaceFactory</span><span class="special">></span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">TypedInPlaceFactory</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">f</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effect:</strong></span> Assigns an <code class="computeroutput"><span class="identifier">optional</span></code> - with a value of <code class="computeroutput"><span class="identifier">T</span></code> obtained - from the factory. - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> - and its value is <span class="emphasis"><em>directly given</em></span> from the factory - <code class="computeroutput"><span class="identifier">f</span></code> (i.e., the value <span class="underline">is not copied</span>). - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Whatever the <code class="computeroutput"><span class="identifier">T</span></code> - constructor called by the factory throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> See <a class="link" href="../tutorial/in_place_factories.html" title="In-Place Factories">In-Place - Factories</a> - </li> -<li class="listitem"> - <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only - be thrown during the call to the <code class="computeroutput"><span class="identifier">T</span></code> - constructor used by the factory; in that case, the <code class="computeroutput"><span class="identifier">optional</span></code> - object will be reset to be <span class="emphasis"><em>uninitialized</em></span>. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_reset_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">reset</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Deprecated:</strong></span> same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">v</span><span class="special">)</span> - <span class="special">;</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_reset"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Deprecated:</strong></span> Same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">none_t</span> - <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_get"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get</span><span class="special">()</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">get</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> - <span class="special">&)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> A reference to the contained - value - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">get</span><span class="special">()</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">get</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> - <span class="keyword">const</span><span class="special">&</span> - <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="special">&)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <span class="underline">The</span> - reference contained. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_asterisk"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> A reference to the contained - value - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - On compilers that do not support ref-qualifiers on member functions these - two overloads are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> - and non-<code class="computeroutput"><span class="keyword">const</span></code> member functions. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> -<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">u</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">opt</span><span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">T</span> <span class="identifier">w</span> <span class="special">;</span> -<span class="special">*</span><span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">w</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">w</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_asterisk_move"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&&;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> contains a value. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">val</span><span class="special">);</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - On compilers that do not support ref-qualifiers on member functions this - overload is not present. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <span class="underline">The</span> - reference contained. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - On compilers that do not support ref-qualifiers on member functions these - three overloads are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code> - member functions. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">T</span><span class="special">&</span> <span class="identifier">vref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">vref</span> <span class="special">);</span> -<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">vref2</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">opt</span><span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">vref2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="special">++</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="special">*</span><span class="identifier">val</span> <span class="special">:</span> <span class="keyword">throw</span> <span class="identifier">bad_optional_access</span><span class="special">();</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions these two overloads are replaced with - the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> - and non-<code class="computeroutput"><span class="keyword">const</span></code> member functions. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o0</span><span class="special">,</span> <span class="identifier">o1</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span><span class="special">.</span><span class="identifier">value</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">);</span> - -<span class="keyword">try</span> <span class="special">{</span> - <span class="identifier">o0</span><span class="special">.</span><span class="identifier">value</span><span class="special">();</span> <span class="comment">// throws</span> - <span class="identifier">assert</span> <span class="special">(</span> <span class="keyword">false</span> <span class="special">);</span> -<span class="special">}</span> -<span class="keyword">catch</span><span class="special">(</span><span class="identifier">bad_optional_access</span><span class="special">&)</span> <span class="special">{</span> - <span class="identifier">assert</span> <span class="special">(</span> <span class="keyword">true</span> <span class="special">);</span> -<span class="special">}</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value_move"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">val</span><span class="special">)</span> <span class="special">:</span> <span class="keyword">throw</span> - <span class="identifier">bad_optional_access</span><span class="special">();</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions this overload is not present. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value_or"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or</span><span class="special">(</span><span class="identifier">U</span> <span class="special">&&</span> - <span class="identifier">v</span><span class="special">)</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">if</span> <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="special">**</span><span class="keyword">this</span><span class="special">;</span> <span class="keyword">else</span> <span class="keyword">return</span> - <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">);</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code> - is not <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> or <code class="computeroutput"><span class="identifier">U</span> <span class="special">&&</span></code> - is not convertible to <code class="computeroutput"><span class="identifier">T</span></code>, - the program is ill-formed. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions this overload is replaced with the - <code class="computeroutput"><span class="keyword">const</span></code>-qualified member function. - On compilers without rvalue reference support the type of <code class="computeroutput"><span class="identifier">v</span></code> becomes <code class="computeroutput"><span class="identifier">U</span> - <span class="keyword">const</span><span class="special">&</span></code>. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value_or_move"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or</span><span class="special">(</span><span class="identifier">U</span> <span class="special">&&</span> - <span class="identifier">v</span><span class="special">)</span> - <span class="special">&&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">if</span> <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(**</span><span class="keyword">this</span><span class="special">);</span> <span class="keyword">else</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">);</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code> - is not <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> - or <code class="computeroutput"><span class="identifier">U</span> <span class="special">&&</span></code> - is not convertible to <code class="computeroutput"><span class="identifier">T</span></code>, - the program is ill-formed. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions this overload is not present. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value_or_call"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">F</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - is <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">F</span></code> models a <a href="http://www.sgi.com/tech/stl/Generator.html" target="_top"><code class="computeroutput"><span class="identifier">Generator</span></code></a> whose result type - is convertible to <code class="computeroutput"><span class="identifier">T</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">if</span> - <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="special">**</span><span class="keyword">this</span><span class="special">;</span> <span class="keyword">else</span> <span class="keyword">return</span> <span class="identifier">f</span><span class="special">();</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions this overload is replaced with the - <code class="computeroutput"><span class="keyword">const</span></code>-qualified member function. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">complain_and_0</span><span class="special">()</span> -<span class="special">{</span> - <span class="identifier">clog</span> <span class="special"><<</span> <span class="string">"no value returned, using default"</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> - <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> -<span class="special">}</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">o1</span> <span class="special">=</span> <span class="number">1</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">oN</span> <span class="special">=</span> <span class="identifier">none</span><span class="special">;</span> - -<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="identifier">o1</span><span class="special">.</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">complain_and_0</span><span class="special">);</span> <span class="comment">// fun not called</span> -<span class="identifier">assert</span> <span class="special">(</span><span class="identifier">i</span> <span class="special">==</span> <span class="number">1</span><span class="special">);</span> - -<span class="keyword">int</span> <span class="identifier">j</span> <span class="special">=</span> <span class="identifier">oN</span><span class="special">.</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">complain_and_0</span><span class="special">);</span> <span class="comment">// fun called</span> -<span class="identifier">assert</span> <span class="special">(</span><span class="identifier">i</span> <span class="special">==</span> <span class="number">0</span><span class="special">);</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_value_or_call_move"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">F</span> <span class="identifier">f</span><span class="special">)</span> <span class="special">&&</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> - and <code class="computeroutput"><span class="identifier">F</span></code> models a <a href="http://www.sgi.com/tech/stl/Generator.html" target="_top"><code class="computeroutput"><span class="identifier">Generator</span></code></a> - whose result type is convertible to <code class="computeroutput"><span class="identifier">T</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">if</span> - <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(**</span><span class="keyword">this</span><span class="special">);</span> <span class="keyword">else</span> <span class="keyword">return</span> - <span class="identifier">f</span><span class="special">();</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - ref-qualifiers on member functions this overload is not present. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_get_value_or_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_value_or</span><span class="special">(</span> - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_value_or</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> - <span class="keyword">default</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">&</span> - <span class="identifier">get_optional_value_or</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">o</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get_optional_value_or</span> - <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>&</span> - <span class="identifier">o</span><span class="special">,</span> - <span class="identifier">T</span><span class="special">&</span> - <span class="keyword">default</span> <span class="special">)</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Deprecated:</strong></span> Use <code class="computeroutput"><span class="identifier">value_or</span><span class="special">()</span></code> instead. - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> A reference to the contained - value, if any, or <code class="computeroutput"><span class="keyword">default</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">,</span> <span class="identifier">z</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span><span class="special">;</span> -<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">def</span><span class="special">.</span><span class="identifier">get_value_or</span><span class="special">(</span><span class="identifier">z</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">y</span> <span class="special">==</span> <span class="identifier">z</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> -<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">u</span> <span class="special">=</span> <span class="identifier">get_optional_value_or</span><span class="special">(</span><span class="identifier">opt</span><span class="special">,</span><span class="identifier">z</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">!=</span> <span class="identifier">z</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_get_ptr"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_ptr</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">*</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> - <span class="keyword">const</span><span class="special">*</span> - <span class="identifier">get_pointer</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">get_pointer</span> - <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> - <span class="special">&)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized, a pointer to the - contained value; else <code class="computeroutput"><span class="number">0</span></code> (<span class="emphasis"><em>null</em></span>). - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The contained value is permanently - stored within <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>, - so you should not hold nor delete this pointer - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span> <span class="identifier">copt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> -<span class="identifier">T</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">opt</span><span class="special">.</span><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span> -<span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">cp</span> <span class="special">=</span> <span class="identifier">copt</span><span class="special">.</span><span class="identifier">get_ptr</span><span class="special">();</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">p</span> <span class="special">==</span> <span class="identifier">get_pointer</span><span class="special">(</span><span class="identifier">opt</span><span class="special">)</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">cp</span> <span class="special">==</span> <span class="identifier">get_pointer</span><span class="special">(</span><span class="identifier">copt</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_arrow"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> - <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span> <span class="special">->()</span> - <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">T</span><span class="special">*</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span> - <span class="special">->()</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized. - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> A pointer to the contained - value. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> Nothing. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> The requirement is asserted via - <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">X</span> <span class="special">{</span> <span class="keyword">int</span> <span class="identifier">mdata</span> <span class="special">;</span> <span class="special">}</span> <span class="special">;</span> -<span class="identifier">X</span> <span class="identifier">x</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">X</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span><span class="identifier">x</span><span class="special">);</span> -<span class="identifier">opt</span><span class="special">-></span><span class="identifier">mdata</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_bool"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span> - <span class="keyword">bool</span><span class="special">()</span> - <span class="keyword">const</span> <span class="keyword">noexcept</span> - <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">!=</span> <span class="number">0</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> On compilers that do not support - explicit conversion operators this falls back to safe-bool idiom. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def</span> <span class="special">==</span> <span class="number">0</span> <span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">!=</span> <span class="number">0</span> <span class="special">);</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_operator_not"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">noexcept</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized, <code class="computeroutput"><span class="keyword">true</span></code>; - else <code class="computeroutput"><span class="keyword">false</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> This operator is provided for - those compilers which can't use the <span class="emphasis"><em>unspecified-bool-type operator</em></span> - in certain boolean contexts. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">opt</span> <span class="special">);</span> -<span class="special">*</span><span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">some_T</span> <span class="special">;</span> - -<span class="comment">// Notice the "double-bang" idiom here.</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!!</span><span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_optional_is_initialized"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">is_initialized</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Deprecated:</strong></span> Same as <code class="computeroutput"><span class="keyword">explicit</span> - <span class="keyword">operator</span> <span class="keyword">bool</span> - <span class="special">()</span> <span class="special">;</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<h5> -<a name="boost_optional.reference.detailed_semantics.h1"></a> - <span class="phrase"><a name="boost_optional.reference.detailed_semantics.free_functions"></a></span><a class="link" href="detailed_semantics.html#boost_optional.reference.detailed_semantics.free_functions">Free - functions</a> - </h5> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_make_optional_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="identifier">make_optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span></code> for the <span class="emphasis"><em>deduced</em></span> - type <code class="computeroutput"><span class="identifier">T</span></code> of <code class="computeroutput"><span class="identifier">v</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">foo</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> - -<span class="identifier">foo</span> <span class="special">(</span> <span class="identifier">make_optional</span><span class="special">(</span><span class="number">1</span><span class="special">+</span><span class="number">1</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// Creates an optional<int></span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_make_optional_bool_value"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="identifier">make_optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">condition</span><span class="special">,</span><span class="identifier">v</span><span class="special">)</span></code> for the <span class="emphasis"><em>deduced</em></span> - type <code class="computeroutput"><span class="identifier">T</span></code> of <code class="computeroutput"><span class="identifier">v</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">calculate_foo</span><span class="special">()</span> -<span class="special">{</span> - <span class="keyword">double</span> <span class="identifier">val</span> <span class="special">=</span> <span class="identifier">compute_foo</span><span class="special">();</span> - <span class="keyword">return</span> <span class="identifier">make_optional</span><span class="special">(</span><span class="identifier">is_not_nan_and_finite</span><span class="special">(</span><span class="identifier">val</span><span class="special">),</span><span class="identifier">val</span><span class="special">);</span> -<span class="special">}</span> - -<span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">calculate_foo</span><span class="special">();</span> -<span class="keyword">if</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">v</span> <span class="special">)</span> - <span class="identifier">error</span><span class="special">(</span><span class="string">"foo wasn't computed"</span><span class="special">);</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">==</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - shall meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>. - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> If both <code class="computeroutput"><span class="identifier">x</span></code> - and <code class="computeroutput"><span class="identifier">y</span></code> are initialized, - <code class="computeroutput"><span class="special">(*</span><span class="identifier">x</span> - <span class="special">==</span> <span class="special">*</span><span class="identifier">y</span><span class="special">)</span></code>. - If only <code class="computeroutput"><span class="identifier">x</span></code> or <code class="computeroutput"><span class="identifier">y</span></code> is initialized, <code class="computeroutput"><span class="keyword">false</span></code>. - If both are uninitialized, <code class="computeroutput"><span class="keyword">true</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> Pointers have shallow relational - operators while <code class="computeroutput"><span class="identifier">optional</span></code> - has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special">==</span></code> directly in generic code which expect - to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#equal" target="_top"><code class="computeroutput"><span class="identifier">equal_pointees</span><span class="special">()</span></code></a> - instead - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">)),</span> <span class="identifier">o1_</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o2</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">));</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN</span> <span class="special">);</span> <span class="comment">// Identity implies equality</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">//</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN_</span> <span class="special">);</span> <span class="comment">// Both uninitialized compare equal</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">!=</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">// Initialized unequal to initialized.</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1_</span> <span class="special">);</span> <span class="comment">// Both initialized compare as (*lhs == *rhs)</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">!=</span> <span class="identifier">o2</span> <span class="special">);</span> <span class="comment">//</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_less_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special"><</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> Expression <code class="computeroutput"><span class="special">*</span><span class="identifier">x</span> <span class="special"><</span> <span class="special">*</span><span class="identifier">y</span></code> - shall be well-formed and its result shall be convertible to <code class="computeroutput"><span class="keyword">bool</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">(!</span><span class="identifier">y</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">false</span> <span class="special">:</span> <span class="special">(!</span><span class="identifier">x</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">true</span> - <span class="special">:</span> <span class="special">*</span><span class="identifier">x</span> <span class="special"><</span> <span class="special">*</span><span class="identifier">y</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> Pointers have shallow relational - operators while <code class="computeroutput"><span class="identifier">optional</span></code> - has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> directly in generic code which expect - to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#less" target="_top"><code class="computeroutput"><span class="identifier">less_pointees</span><span class="special">()</span></code></a> - instead. <code class="computeroutput"><span class="identifier">T</span></code> need not be - <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>. Only single - <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> - is required. Other relational operations are defined in terms of this - one. If <code class="computeroutput"><span class="identifier">T</span></code>'s <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> - satisfies the axioms of <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a> (transitivity, - antisymmetry and irreflexivity), <code class="computeroutput"><span class="identifier">optinal</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> is <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o0</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">0</span><span class="special">));</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Identity implies equivalence</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o1</span> <span class="special"><</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">);</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">oN_</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Two uninitialized are equivalent</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN_</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">o0</span> <span class="special">);</span> <span class="comment">// Uninitialized is less than initialized</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o0</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> - -<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special"><</span> <span class="identifier">o2</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// Two initialized compare as (*lhs < *rhs)</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special"><</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special"><</span> <span class="identifier">o2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> -</pre> - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_not_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> - <span class="identifier">x</span> <span class="special">==</span> - <span class="identifier">y</span> <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_greater_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">></span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">(</span> - <span class="identifier">y</span> <span class="special"><</span> - <span class="identifier">x</span> <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_less_or_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special"><=</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> - <span class="identifier">y</span> <span class="special"><</span> - <span class="identifier">x</span> <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_greater_or_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">>=</span> <span class="special">(</span> - <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> - <span class="identifier">x</span> <span class="special"><</span> - <span class="identifier">y</span> <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_equal_optional_none"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">==</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> - <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">==</span> <span class="special">(</span> <span class="identifier">none_t</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">!</span><span class="identifier">x</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> - need not meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>. - </li> -</ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_operator_compare_not_equal_optional_none"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> - <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> - <span class="special">!=</span> <span class="special">(</span> <span class="identifier">none_t</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> - <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> - <span class="identifier">x</span> <span class="special">==</span> - <span class="identifier">y</span> <span class="special">);</span></code> - </li></ul></div> -<p> - <span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span> - </p> -<a name="reference_swap_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> - <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">swap</span> - <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">y</span> - <span class="special">)</span> <span class="special">;</span></code> - </p></blockquote></div> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"> - <span class="bold"><strong>Requires:</strong></span> Lvalues of type <code class="computeroutput"><span class="identifier">T</span></code> shall be swappable and <code class="computeroutput"><span class="identifier">T</span></code> shall be <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>. - </li> -<li class="listitem"> - <span class="bold"><strong>Effects:</strong></span> - <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "> -<li class="listitem"> - If <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code>, no effect, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="special">!</span><span class="identifier">rhs</span></code>, initializes the contained - value of <code class="computeroutput"><span class="identifier">rhs</span></code> as - if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code> - with the expression <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">))</span></code>, followed by <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> does not contain a value and - <code class="computeroutput"><span class="identifier">rhs</span></code> contains a - value, otherwise - </li> -<li class="listitem"> - if <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>, initializes the contained value - of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> - as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code> - with the expression <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code>, followed by <code class="computeroutput"><span class="identifier">rhs</span><span class="special">.</span><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> contains a value and <code class="computeroutput"><span class="identifier">rhs</span></code> does not contain a value, - otherwise - </li> -<li class="listitem"> - (if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> - <span class="special">&&</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>) calls <code class="computeroutput"><span class="identifier">swap</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">),</span> <span class="special">*</span><span class="identifier">rhs</span><span class="special">)</span></code>. - </li> -</ul></div> - </li> -<li class="listitem"> - <span class="bold"><strong>Postconditions:</strong></span> The states of <code class="computeroutput"><span class="identifier">x</span></code> and <code class="computeroutput"><span class="identifier">y</span></code> - interchanged. - </li> -<li class="listitem"> - <span class="bold"><strong>Throws:</strong></span> If both are initialized, whatever - <code class="computeroutput"><span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&,</span><span class="identifier">T</span><span class="special">&)</span></code> - throws. If only one is initialized, whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> - throws. - </li> -<li class="listitem"> - <span class="bold"><strong>Example:</strong></span> -<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">(</span><span class="number">12</span><span class="special">);</span> -<span class="identifier">T</span> <span class="identifier">y</span><span class="special">(</span><span class="number">21</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def0</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def1</span> <span class="special">;</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">optX</span><span class="special">(</span><span class="identifier">x</span><span class="special">);</span> -<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">optY</span><span class="special">(</span><span class="identifier">y</span><span class="special">);</span> - -<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">def1</span><span class="special">);</span> <span class="comment">// no-op</span> - -<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">optX</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def0</span> <span class="special">==</span> <span class="identifier">x</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">optX</span> <span class="special">);</span> - -<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">optX</span><span class="special">);</span> <span class="comment">// Get back to original values</span> - -<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">optX</span><span class="special">,</span><span class="identifier">optY</span><span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">);</span> -<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">optY</span> <span class="special">==</span> <span class="identifier">x</span> <span class="special">);</span> -</pre> - </li> -</ul></div> -</div> -<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> -<td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> - Distributed under the Boost Software License, Version 1.0. (See accompanying - file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) - </p> -</div></td> -</tr></table> -<hr> -<div class="spirit-nav"> -<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> -</div> -</body> -</html> diff --git a/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_.html b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_.html new file mode 100644 index 000000000..e0d8ba9ca --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_.html @@ -0,0 +1,63 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Header <boost/optional/bad_optional_access.hpp></title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/reference.html" title="Reference"> +<link rel="prev" href="../../optional/reference.html" title="Reference"> +<link rel="next" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html" title="Detailed semantics"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.reference.header__boost_optional_bad_optional_access_hpp_"></a><a class="link" href="header__boost_optional_bad_optional_access_hpp_.html" title="Header <boost/optional/bad_optional_access.hpp>">Header + <boost/optional/bad_optional_access.hpp></a> +</h3></div></div></div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.header__boost_optional_bad_optional_access_hpp_.synopsis"></a><a class="link" href="header__boost_optional_bad_optional_access_hpp_.html#boost_optional.reference.header__boost_optional_bad_optional_access_hpp_.synopsis" title="Synopsis">Synopsis</a> +</h4></div></div></div> +<p> +</p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + +<span class="keyword">class</span> <span class="identifier">bad_optional_access</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">logic_error</span> +<span class="special">{</span> +<span class="keyword">public</span><span class="special">:</span> + <span class="identifier">bad_optional_access</span><span class="special">();</span> <a class="link" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html#reference_bad_optional_access_constructor"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> +<span class="special">};</span> + +<span class="special">}</span> <span class="comment">// namespace boost</span> +</pre> +<p> + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html new file mode 100644 index 000000000..2b69cac08 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html @@ -0,0 +1,60 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Detailed semantics</title> +<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../../index.html" title="Boost.Optional"> +<link rel="up" href="../header__boost_optional_bad_optional_access_hpp_.html" title="Header <boost/optional/bad_optional_access.hpp>"> +<link rel="prev" href="../header__boost_optional_bad_optional_access_hpp_.html" title="Header <boost/optional/bad_optional_access.hpp>"> +<link rel="next" href="../io_header.html" title="Header <boost/optional/optional_io.hpp>"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../header__boost_optional_bad_optional_access_hpp_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../header__boost_optional_bad_optional_access_hpp_.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../io_header.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.header__boost_optional_bad_optional_access_hpp_.detailed_semantics"></a><a class="link" href="detailed_semantics.html" title="Detailed semantics">Detailed + semantics</a> +</h4></div></div></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<p> + <a name="reference_bad_optional_access_constructor"></a><code class="computeroutput"><span class="identifier">bad_optional_access</span><span class="special">();</span></code> + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Constructs an object of class + <code class="computeroutput"><span class="identifier">bad_optional_access</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="identifier">what</span><span class="special">()</span></code> returns an implementation-defined + NTBS. + </li> +</ul></div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../header__boost_optional_bad_optional_access_hpp_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../header__boost_optional_bad_optional_access_hpp_.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../io_header.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/header__boost_optional_hpp_.html b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_hpp_.html new file mode 100644 index 000000000..19ed6cf5a --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_hpp_.html @@ -0,0 +1,47 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Header <boost/optional.hpp></title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/reference.html" title="Reference"> +<link rel="prev" href="header__boost_optional_optional_hpp_/detailed_semantics.html" title="Detailed Semantics"> +<link rel="next" href="../dependencies_and_portability.html" title="Dependencies and Portability"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="header__boost_optional_optional_hpp_/detailed_semantics.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.reference.header__boost_optional_hpp_"></a><a class="link" href="header__boost_optional_hpp_.html" title="Header <boost/optional.hpp>">Header + <boost/optional.hpp></a> +</h3></div></div></div> +<p> + This is an alias for header <a class="link" href="../../optional/reference/header__boost_optional_optional_hpp_.html#boost_optional.reference.header__boost_optional_optional_hpp_.header_optional_optional" title="Synopsis"><code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">/</span><span class="identifier">optional</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code></a>. + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="header__boost_optional_optional_hpp_/detailed_semantics.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../dependencies_and_portability.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_fwd_hpp_.html b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_fwd_hpp_.html new file mode 100644 index 000000000..d87a47382 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_fwd_hpp_.html @@ -0,0 +1,66 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Header <boost/optional/optional_fwd.hpp></title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/reference.html" title="Reference"> +<link rel="prev" href="io_header/io_semantics.html" title="Detailed semantics"> +<link rel="next" href="../../optional/reference/header__boost_optional_optional_hpp_.html" title="Header <boost/optional/optional.hpp>"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="io_header/io_semantics.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.reference.header__boost_optional_optional_fwd_hpp_"></a><a class="link" href="header__boost_optional_optional_fwd_hpp_.html" title="Header <boost/optional/optional_fwd.hpp>">Header + <boost/optional/optional_fwd.hpp></a> +</h3></div></div></div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.header__boost_optional_optional_fwd_hpp_.synopsis"></a><a class="link" href="header__boost_optional_optional_fwd_hpp_.html#boost_optional.reference.header__boost_optional_optional_fwd_hpp_.synopsis" title="Synopsis">Synopsis</a> +</h4></div></div></div> +<p> +</p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">class</span> <span class="identifier">optional</span> <span class="special">;</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">swap</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="special">);</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">optional_swap_should_use_default_constructor</span> <span class="special">;</span> + +<span class="special">}</span> <span class="comment">// namespace boost</span> +</pre> +<p> + </p> +<p> + This header only contains declarations. + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="io_header/io_semantics.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics.html b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics.html new file mode 100644 index 000000000..a54a5834a --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics.html @@ -0,0 +1,2387 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Detailed Semantics</title> +<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../../index.html" title="Boost.Optional"> +<link rel="up" href="../../../optional/reference/header__boost_optional_optional_hpp_.html" title="Header <boost/optional/optional.hpp>"> +<link rel="prev" href="../../../optional/reference/header__boost_optional_optional_hpp_.html" title="Header <boost/optional/optional.hpp>"> +<link rel="next" href="../header__boost_optional_hpp_.html" title="Header <boost/optional.hpp>"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../header__boost_optional_hpp_.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics"></a><a class="link" href="detailed_semantics.html" title="Detailed Semantics">Detailed + Semantics</a> +</h4></div></div></div> +<p> + Because <code class="computeroutput"><span class="identifier">T</span></code> might be of reference + type, in the sequel, those entries whose semantic depends on <code class="computeroutput"><span class="identifier">T</span></code> being of reference type or not will + be distinguished using the following convention: + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code><span class="emphasis"><em>(not + a ref)</em></span><code class="computeroutput"><span class="special">></span></code>, + the description corresponds only to the case where <code class="computeroutput"><span class="identifier">T</span></code> + is not of reference type. + </li> +<li class="listitem"> + If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span></code>, the description corresponds + only to the case where <code class="computeroutput"><span class="identifier">T</span></code> + is of reference type. + </li> +<li class="listitem"> + If the entry reads: <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code>, the description is the same for + both cases. + </li> +</ul></div> +<div class="note"><table border="0" summary="Note"> +<tr> +<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td> +<th align="left">Note</th> +</tr> +<tr><td align="left" valign="top"><p> + The following section contains various <code class="computeroutput"><span class="identifier">assert</span><span class="special">()</span></code> which are used only to show the postconditions + as sample code. It is not implied that the type <code class="computeroutput"><span class="identifier">T</span></code> + must support each particular expression but that if the expression is + supported, the implied condition holds. + </p></td></tr> +</table></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<h6> +<a name="boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.h0"></a> + <span class="phrase"><a name="boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.optional_class_member_functions"></a></span><a class="link" href="detailed_semantics.html#boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.optional_class_member_functions">optional + class member functions</a> + </h6> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">optional</span><span class="special">()</span> + <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Default-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">uninitialized</span>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> T's default constructor <span class="underline">is not</span> called. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_none_t"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">none_t</span> <span class="special">)</span> + <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Constructs an <code class="computeroutput"><span class="identifier">optional</span></code> uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">uninitialized</span>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>'s + default constructor <span class="underline">is not</span> called. + The expression <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> + denotes an instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none_t</span></code> + that can be used as the parameter. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">none</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">n</span><span class="special">(</span><span class="identifier">none</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">n</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_copy_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> + is <code class="computeroutput"><span class="keyword">true</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Directly-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> + and its value is a <span class="emphasis"><em>copy</em></span> of <code class="computeroutput"><span class="identifier">v</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> is called. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">);</span></code> in that case, this constructor + has no effect. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">T</span><span class="special">&</span> + <span class="identifier">ref</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Directly-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> + and its value is an instance of an internal type wrapping the reference + <code class="computeroutput"><span class="identifier">ref</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">vref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">vref</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="special">++</span> <span class="identifier">v</span> <span class="special">;</span> <span class="comment">// mutate referee</span> +<span class="identifier">assert</span> <span class="special">(*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span><span class="special">);</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_move_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">v</span> + <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> + is <code class="computeroutput"><span class="keyword">true</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Directly-Move-Constructs an + <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> + and its value is move-constructed from <code class="computeroutput"><span class="identifier">v</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> + is called. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">);</span></code> + in that case, the state of <code class="computeroutput"><span class="identifier">v</span></code> + is determined by exception safety guarantees for <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span><span class="special">&&)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v1</span><span class="special">,</span> <span class="identifier">v2</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">v1</span><span class="special">));</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v2</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">T</span><span class="special">&&</span> + <span class="identifier">ref</span> <span class="special">)</span> + <span class="special">=</span> <span class="keyword">delete</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> This constructor is deleted + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_bool_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> + <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="special">::</span><span class="identifier">optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> + <span class="identifier">T</span><span class="special">&</span> + <span class="identifier">v</span> <span class="special">)</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + If condition is true, same as: + </li></ul></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="special">::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + otherwise, same as: + </li></ul></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">()</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="special">::</span><span class="identifier">optional</span><span class="special">()</span></code> + </p></blockquote></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">rhs</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_copy_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> + is <code class="computeroutput"><span class="keyword">true</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If rhs is initialized, + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is a <span class="emphasis"><em>copy</em></span> of the + value of <code class="computeroutput"><span class="identifier">rhs</span></code>; else + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If rhs is initialized, <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span></code> + is called. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">);</span></code> in that case, this constructor + has no effect. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">uninit</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">uninit</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init</span><span class="special">(</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">optional</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> + <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is another reference to the same object + referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; + else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> will refer to the same object + (they alias). + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">uninit</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">uninit</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> + +<span class="identifier">T</span> <span class="identifier">v</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">ref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init</span><span class="special">(</span><span class="identifier">ref</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">v</span> <span class="special">=</span> <span class="number">3</span> <span class="special">;</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_move_constructor_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span> </code><span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span></code><span class="emphasis"><em>see below</em></span><code class="computeroutput"><span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">is_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code> + is <code class="computeroutput"><span class="keyword">true</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Move-constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is move constructed from <code class="computeroutput"><span class="identifier">rhs</span></code>; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Remarks:</strong></span> The expression inside <code class="computeroutput"><span class="keyword">noexcept</span></code> is equivalent to <code class="computeroutput"><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="special">&&</span> + <span class="special">)</span></code> is called. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">);</span></code> + in that case, <code class="computeroutput"><span class="identifier">rhs</span></code> remains + initialized and the value of <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> is determined by exception safety + of <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span><span class="special">&&)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">uninit</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">uninit</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">init</span><span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">uniqye_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">init</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="keyword">nullptr</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">init2</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">optional</span> <span class="special">&&</span> + <span class="identifier">rhs</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Move-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is another reference to the same object + referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; + else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> will refer to the same object + (they alias). + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">uninit</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(!</span><span class="identifier">uninit</span><span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">uinit2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">uninit</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">uninit2</span> <span class="special">==</span> <span class="identifier">uninit</span> <span class="special">);</span> + +<span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">v</span><span class="special">(</span><span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">init</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&></span> <span class="identifier">init2</span> <span class="special">(</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">init</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">init2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> + +<span class="special">*</span><span class="identifier">v</span> <span class="special">=</span> <span class="number">3</span> <span class="special">;</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">**</span><span class="identifier">init2</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Copy-Constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is a <span class="emphasis"><em>copy</em></span> of the + value of rhs converted to type <code class="computeroutput"><span class="identifier">T</span></code>; + else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> is called if <code class="computeroutput"><span class="identifier">rhs</span></code> is initialized, which requires + a valid conversion from <code class="computeroutput"><span class="identifier">U</span></code> + to <code class="computeroutput"><span class="identifier">T</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">);</span></code> in that case, this constructor + has no effect. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span><span class="number">123.4</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="number">123.4</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span><span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="number">123</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_move_constructor_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> + <span class="identifier">rhs</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Move-constructs an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code> + is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and its value is move-constructed from <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; + else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes: </strong></span> <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">)</span></code> + is called if <code class="computeroutput"><span class="identifier">rhs</span></code> is + initialized, which requires a valid conversion from <code class="computeroutput"><span class="identifier">U</span></code> + to <code class="computeroutput"><span class="identifier">T</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> <span class="special">);</span></code> + in that case, <code class="computeroutput"><span class="identifier">rhs</span></code> remains + initialized and the value of <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> is determined by exception safety + guarantee of <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">U</span><span class="special">&&</span> + <span class="special">)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span><span class="number">123.4</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="number">123.4</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">))</span> <span class="special">;</span> +<span class="identifier">assert</span><span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="number">123</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_constructor_factory"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">InPlaceFactory</span><span class="special">></span> + <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">InPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">TypedInPlaceFactory</span><span class="special">></span> + <span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">optional</span><span class="special">(</span> + <span class="identifier">TypedInPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Constructs an <code class="computeroutput"><span class="identifier">optional</span></code> with a value of <code class="computeroutput"><span class="identifier">T</span></code> obtained from the factory. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> + and its value is <span class="emphasis"><em>directly given</em></span> from the factory + <code class="computeroutput"><span class="identifier">f</span></code> (i.e., the value + <span class="underline">is not copied</span>). + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever the <code class="computeroutput"><span class="identifier">T</span></code> constructor called by the factory + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> See <a class="link" href="../../tutorial/in_place_factories.html" title="In-Place Factories">In-Place + Factories</a> + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during the call to the <code class="computeroutput"><span class="identifier">T</span></code> + constructor used by the factory; in that case, this constructor has + no effect. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">C</span> <span class="special">{</span> <span class="identifier">C</span> <span class="special">(</span> <span class="keyword">char</span><span class="special">,</span> <span class="keyword">double</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">)</span> <span class="special">;</span> <span class="special">}</span> <span class="special">;</span> + +<span class="identifier">C</span> <span class="identifier">v</span><span class="special">(</span><span class="char">'A'</span><span class="special">,</span><span class="number">123.4</span><span class="special">,</span><span class="string">"hello"</span><span class="special">);</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">x</span><span class="special">(</span> <span class="identifier">in_place</span> <span class="special">(</span><span class="char">'A'</span><span class="special">,</span> <span class="number">123.4</span><span class="special">,</span> <span class="string">"hello"</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// InPlaceFactory used</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">y</span><span class="special">(</span> <span class="identifier">in_place</span><span class="special"><</span><span class="identifier">C</span><span class="special">>(</span><span class="char">'A'</span><span class="special">,</span> <span class="number">123.4</span><span class="special">,</span> <span class="string">"hello"</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// TypedInPlaceFactory used</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">y</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_equal_none_t"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">none_t</span> + <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized destroys its contained + value. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_equal_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">rhs</span> <span class="special">)</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Assigns the value <code class="computeroutput"><span class="identifier">rhs</span></code> to an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and its value is + a <span class="emphasis"><em>copy</em></span> of <code class="computeroutput"><span class="identifier">rhs</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span></code> or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s assignment operator is used, + otherwise, its copy-constructor is used. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> In the event of + an exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified + as far as <code class="computeroutput"><span class="identifier">optional</span></code> + is concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s + <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). + If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s + <span class="emphasis"><em>copy constructor</em></span> fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> + +<span class="identifier">T</span> <span class="identifier">y</span><span class="special">;</span> +<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">y</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">y</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> (Re)binds the wrapped reference. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and it references + the same object referenced by <code class="computeroutput"><span class="identifier">rhs</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, it is <span class="emphasis"><em>rebound</em></span> + to the new object. See <a class="link" href="../../tutorial/rebinding_semantics_for_assignment_of_optional_references.html" title="Rebinding semantics for assignment of optional references">here</a> + for details on this behavior. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">a</span> <span class="special">=</span> <span class="number">1</span> <span class="special">;</span> +<span class="keyword">int</span> <span class="identifier">b</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">ra</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">rb</span> <span class="special">=</span> <span class="identifier">b</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">ra</span><span class="special">)</span> <span class="special">;</span> + +<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">rb</span> <span class="special">;</span> <span class="comment">// binds 'def' to 'b' through 'rb'</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">b</span> <span class="special">)</span> <span class="special">;</span> +<span class="special">*</span><span class="identifier">def</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> <span class="comment">// changes the value of 'b' to a copy of the value of 'a'</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">b</span> <span class="special">==</span> <span class="identifier">a</span> <span class="special">)</span> <span class="special">;</span> +<span class="keyword">int</span> <span class="identifier">c</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> +<span class="keyword">int</span><span class="special">&</span> <span class="identifier">rc</span> <span class="special">=</span> <span class="identifier">c</span> <span class="special">;</span> +<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">rc</span> <span class="special">;</span> <span class="comment">// REBINDS to 'c' through 'rc'</span> +<span class="identifier">c</span> <span class="special">=</span> <span class="number">4</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="number">4</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_move_equal_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Moves the value <code class="computeroutput"><span class="identifier">rhs</span></code> to an <code class="computeroutput"><span class="identifier">optional</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized and its value is + moved from <code class="computeroutput"><span class="identifier">rhs</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> + or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&&)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s move-assignment operator is used, + otherwise, its move-constructor is used. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> In the event of + an exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified + as far as <code class="computeroutput"><span class="identifier">optional</span></code> + is concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s + <code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>). + If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s + <span class="emphasis"><em>move constructor</em></span> fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">;</span> + +<span class="identifier">T</span> <span class="identifier">y1</span><span class="special">,</span> <span class="identifier">y2</span><span class="special">,</span> <span class="identifier">yR</span><span class="special">;</span> +<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">y1</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">yR</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">y2</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">yR</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">=</span> + <span class="keyword">delete</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> This assignment operator is + deleted. + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_equal_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">rhs</span> <span class="special">)</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + is <a href="../../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">CopyAssignable</span></code>. + </li> +<li class="listitem"> +<p class="simpara"> + <span class="bold"><strong>Effects:</strong></span> + </p> +<div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<thead><tr> +<th> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value + </p> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + does not contain a value + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + assigns <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> + to the contained value + </p> + </td> +<td> + <p> + initializes the contained value as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> does + not contain a value + </p> + </td> +<td> + <p> + destroys the contained value by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code> + </p> + </td> +<td> + <p> + no effect + </p> + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>; + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> If any exception + is thrown, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code> + remains unchanged. If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s copy constructor, no effect. + If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s + copy assignment, the state of its contained value is as defined by + the exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s + copy assignment. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> + +<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> +<span class="comment">// previous value (copy of 'v') destroyed from within 'opt'.</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> (Re)binds thee wrapped reference. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is initialized and it references the same object referenced by <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>; + otherwise, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is uninitialized (and references no object). + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> was initialized and so is <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>, + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is <span class="emphasis"><em>rebound</em></span> to the new object. See <a class="link" href="../../tutorial/rebinding_semantics_for_assignment_of_optional_references.html" title="Rebinding semantics for assignment of optional references">here</a> + for details on this behavior. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">a</span> <span class="special">=</span> <span class="number">1</span> <span class="special">;</span> +<span class="keyword">int</span> <span class="identifier">b</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">ra</span> <span class="special">=</span> <span class="identifier">a</span> <span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">rb</span> <span class="special">=</span> <span class="identifier">b</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">ora</span><span class="special">(</span><span class="identifier">ra</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">orb</span><span class="special">(</span><span class="identifier">rb</span><span class="special">)</span> <span class="special">;</span> + +<span class="identifier">def</span> <span class="special">=</span> <span class="identifier">orb</span> <span class="special">;</span> <span class="comment">// binds 'def' to 'b' through 'rb' wrapped within 'orb'</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def</span> <span class="special">==</span> <span class="identifier">b</span> <span class="special">)</span> <span class="special">;</span> +<span class="special">*</span><span class="identifier">def</span> <span class="special">=</span> <span class="identifier">ora</span> <span class="special">;</span> <span class="comment">// changes the value of 'b' to a copy of the value of 'a'</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">b</span> <span class="special">==</span> <span class="identifier">a</span> <span class="special">)</span> <span class="special">;</span> +<span class="keyword">int</span> <span class="identifier">c</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> +<span class="keyword">int</span><span class="special">&</span> <span class="identifier">rc</span> <span class="special">=</span> <span class="identifier">c</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">&></span> <span class="identifier">orc</span><span class="special">(</span><span class="identifier">rc</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">ora</span> <span class="special">=</span> <span class="identifier">orc</span> <span class="special">;</span> <span class="comment">// REBINDS ora to 'c' through 'rc'</span> +<span class="identifier">c</span> <span class="special">=</span> <span class="number">4</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">ora</span> <span class="special">==</span> <span class="number">4</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_move_equal_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span></code><span class="emphasis"><em>see below</em></span><code class="computeroutput"><span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> + and <code class="computeroutput"><span class="identifier">MoveAssignable</span></code>. + </li> +<li class="listitem"> +<p class="simpara"> + <span class="bold"><strong>Effects:</strong></span> + </p> +<div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<thead><tr> +<th> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value + </p> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + does not contain a value + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + assigns <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> to the contained value + </p> + </td> +<td> + <p> + initializes the contained value as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> does + not contain a value + </p> + </td> +<td> + <p> + destroys the contained value by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code> + </p> + </td> +<td> + <p> + no effect + </p> + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>; + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Remarks:</strong></span> The expression inside <code class="computeroutput"><span class="keyword">noexcept</span></code> is equivalent to <code class="computeroutput"><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span> <span class="special">&&</span> + <span class="identifier">is_nothrow_move_assignable</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> If any exception + is thrown, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code> + remains unchanged. If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s move constructor, the state of + <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> + is determined by the exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s + move constructor. If an exception is thrown during the call to T's + move-assignment, the state of <code class="computeroutput"><span class="special">**</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> is determined by the exception + safety guarantee of T's move assignment. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">))</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> + +<span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Same as <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">rhs</span> <span class="special">)</span></code>. + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_equal_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> +<p class="simpara"> + <span class="bold"><strong>Effect:</strong></span> + </p> +<div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<thead><tr> +<th> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value + </p> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + does not contain a value + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + assigns <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> + to the contained value + </p> + </td> +<td> + <p> + initializes the contained value as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> does + not contain a value + </p> + </td> +<td> + <p> + destroys the contained value by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code> + </p> + </td> +<td> + <p> + no effect + </p> + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> If any exception + is thrown, the result of the expression <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code> remains unchanged. If an exception + is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s + constructor, no effect. If an exception is thrown during the call to + <code class="computeroutput"><span class="identifier">T</span></code>'s assignment, the + state of its contained value is as defined by the exception safety + guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s copy + assignment. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt0</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">opt1</span><span class="special">;</span> + +<span class="identifier">opt1</span> <span class="special">=</span> <span class="identifier">opt0</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt1</span> <span class="special">==</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_move_equal_other_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> <span class="identifier">rhs</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> +<p class="simpara"> + <span class="bold"><strong>Effect:</strong></span> + </p> +<div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<thead><tr> +<th> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value + </p> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + does not contain a value + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + assigns <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> to the contained value + </p> + </td> +<td> + <p> + initializes the contained value as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> does + not contain a value + </p> + </td> +<td> + <p> + destroys the contained value by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code> + </p> + </td> +<td> + <p> + no effect + </p> + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> If any exception + is thrown, the result of the expression <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code> remains unchanged. If an exception + is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s + constructor, no effect. If an exception is thrown during the call to + <code class="computeroutput"><span class="identifier">T</span></code>'s assignment, the + state of its contained value is as defined by the exception safety + guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s copy + assignment. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt0</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="identifier">opt1</span><span class="special">;</span> + +<span class="identifier">opt1</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">opt0</span><span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt0</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt1</span> <span class="special">)</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt1</span> <span class="special">==</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_emplace"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span><span class="special">...</span> <span class="identifier">Args</span><span class="special">></span> + <span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">emplace</span><span class="special">(</span> + <span class="identifier">Args</span><span class="special">...&&</span> + <span class="identifier">args</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> The compiler supports rvalue + references and variadic templates. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized calls <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">=</span> <span class="identifier">none</span></code>. + Then initializes in-place the contained value as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">Args</span><span class="special">>(</span><span class="identifier">args</span><span class="special">)...</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever the selected <code class="computeroutput"><span class="identifier">T</span></code>'s constructor throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + need not be <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> + or <code class="computeroutput"><span class="identifier">MoveAssignable</span></code>. + On compilers that do not support variadic templates, the signature + falls back to single-argument: <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> + <span class="identifier">Arg</span><span class="special">></span> + <span class="keyword">void</span> <span class="identifier">emplace</span><span class="special">(</span><span class="identifier">Arg</span><span class="special">&&</span> <span class="identifier">arg</span><span class="special">)</span></code>. On compilers that do not support + rvalue references, the signature falls back to two overloads: taking + <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code> lvalue reference. + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> If an exception + is thrown during the initialization of <code class="computeroutput"><span class="identifier">T</span></code>, + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + is <span class="emphasis"><em>uninitialized</em></span>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">;</span> +<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">(</span><span class="number">0</span><span class="special">);</span> <span class="comment">// create in-place using ctor T(int)</span> +<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">();</span> <span class="comment">// destroy previous and default-construct another T</span> +<span class="identifier">opt</span><span class="special">.</span><span class="identifier">emplace</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> <span class="comment">// destroy and copy-construct in-place (no assignment called)</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_equal_factory"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">InPlaceFactory</span><span class="special">></span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">InPlaceFactory</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">f</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="identifier">TypedInPlaceFactory</span><span class="special">></span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">TypedInPlaceFactory</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">f</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Assigns an <code class="computeroutput"><span class="identifier">optional</span></code> + with a value of <code class="computeroutput"><span class="identifier">T</span></code> obtained + from the factory. + </li> +<li class="listitem"> + <span class="bold"><strong>Postconditions: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is <span class="underline">initialized</span> + and its value is <span class="emphasis"><em>directly given</em></span> from the factory + <code class="computeroutput"><span class="identifier">f</span></code> (i.e., the value + <span class="underline">is not copied</span>). + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Whatever the <code class="computeroutput"><span class="identifier">T</span></code> constructor called by the factory + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> See <a class="link" href="../../tutorial/in_place_factories.html" title="In-Place Factories">In-Place + Factories</a> + </li> +<li class="listitem"> + <span class="bold"><strong>Exception Safety:</strong></span> Exceptions can only + be thrown during the call to the <code class="computeroutput"><span class="identifier">T</span></code> + constructor used by the factory; in that case, the <code class="computeroutput"><span class="identifier">optional</span></code> + object will be reset to be <span class="emphasis"><em>uninitialized</em></span>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_reset_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">reset</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Deprecated:</strong></span> same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=</span> + <span class="special">(</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">v</span><span class="special">)</span> + <span class="special">;</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_reset"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Deprecated:</strong></span> Same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span> + <span class="identifier">none_t</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_get"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get</span><span class="special">()</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">get</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span> + <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> + <span class="special">&)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> A reference to the contained + value + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="identifier">get</span><span class="special">()</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">get</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> + <span class="keyword">const</span><span class="special">&</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span> + <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="special">&)</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <span class="underline">The</span> + reference contained. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_asterisk"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> A reference to the contained + value + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + On compilers that do not support ref-qualifiers on member functions + these two overloads are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code> + member functions. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> +<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">u</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">opt</span><span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">T</span> <span class="identifier">w</span> <span class="special">;</span> +<span class="special">*</span><span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">w</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">w</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_asterisk_move"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&&;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> contains a value. + </li> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">val</span><span class="special">);</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + On compilers that do not support ref-qualifiers on member functions + this overload is not present. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> + <span class="special">&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&>::</span><span class="keyword">operator</span><span class="special">*()</span> + <span class="special">&&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <span class="underline">The</span> + reference contained. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + On compilers that do not support ref-qualifiers on member functions + these three overloads are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code> + member functions. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">T</span><span class="special">&</span> <span class="identifier">vref</span> <span class="special">=</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">vref</span> <span class="special">);</span> +<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">vref2</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">opt</span><span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">vref2</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="special">++</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="special">*</span><span class="identifier">val</span> <span class="special">:</span> <span class="keyword">throw</span> <span class="identifier">bad_optional_access</span><span class="special">();</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions these two overloads are replaced + with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> + and non-<code class="computeroutput"><span class="keyword">const</span></code> member functions. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o0</span><span class="special">,</span> <span class="identifier">o1</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span><span class="special">.</span><span class="identifier">value</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">);</span> + +<span class="keyword">try</span> <span class="special">{</span> + <span class="identifier">o0</span><span class="special">.</span><span class="identifier">value</span><span class="special">();</span> <span class="comment">// throws</span> + <span class="identifier">assert</span> <span class="special">(</span> <span class="keyword">false</span> <span class="special">);</span> +<span class="special">}</span> +<span class="keyword">catch</span><span class="special">(</span><span class="identifier">bad_optional_access</span><span class="special">&)</span> <span class="special">{</span> + <span class="identifier">assert</span> <span class="special">(</span> <span class="keyword">true</span> <span class="special">);</span> +<span class="special">}</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value_move"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">val</span><span class="special">)</span> <span class="special">:</span> <span class="keyword">throw</span> <span class="identifier">bad_optional_access</span><span class="special">();</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions this overload is not present. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value_or"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or</span><span class="special">(</span><span class="identifier">U</span> <span class="special">&&</span> + <span class="identifier">v</span><span class="special">)</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">if</span> <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="special">**</span><span class="keyword">this</span><span class="special">;</span> <span class="keyword">else</span> <span class="keyword">return</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">);</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code> + is not <a href="../../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> or <code class="computeroutput"><span class="identifier">U</span> <span class="special">&&</span></code> + is not convertible to <code class="computeroutput"><span class="identifier">T</span></code>, + the program is ill-formed. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions this overload is replaced with the + <code class="computeroutput"><span class="keyword">const</span></code>-qualified member + function. On compilers without rvalue reference support the type of + <code class="computeroutput"><span class="identifier">v</span></code> becomes <code class="computeroutput"><span class="identifier">U</span> <span class="keyword">const</span><span class="special">&</span></code>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value_or_move"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or</span><span class="special">(</span><span class="identifier">U</span> <span class="special">&&</span> + <span class="identifier">v</span><span class="special">)</span> + <span class="special">&&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">if</span> <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(**</span><span class="keyword">this</span><span class="special">);</span> <span class="keyword">else</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">U</span><span class="special">>(</span><span class="identifier">v</span><span class="special">);</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code> + is not <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> + or <code class="computeroutput"><span class="identifier">U</span> <span class="special">&&</span></code> + is not convertible to <code class="computeroutput"><span class="identifier">T</span></code>, + the program is ill-formed. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions this overload is not present. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value_or_call"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">F</span> <span class="identifier">f</span><span class="special">)</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + is <a href="../../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">F</span></code> models a <a href="http://www.sgi.com/tech/stl/Generator.html" target="_top"><code class="computeroutput"><span class="identifier">Generator</span></code></a> whose result type + is convertible to <code class="computeroutput"><span class="identifier">T</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">if</span> + <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="special">**</span><span class="keyword">this</span><span class="special">;</span> <span class="keyword">else</span> <span class="keyword">return</span> <span class="identifier">f</span><span class="special">();</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions this overload is replaced with the + <code class="computeroutput"><span class="keyword">const</span></code>-qualified member + function. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">complain_and_0</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">clog</span> <span class="special"><<</span> <span class="string">"no value returned, using default"</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">o1</span> <span class="special">=</span> <span class="number">1</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">oN</span> <span class="special">=</span> <span class="identifier">none</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="identifier">o1</span><span class="special">.</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">complain_and_0</span><span class="special">);</span> <span class="comment">// fun not called</span> +<span class="identifier">assert</span> <span class="special">(</span><span class="identifier">i</span> <span class="special">==</span> <span class="number">1</span><span class="special">);</span> + +<span class="keyword">int</span> <span class="identifier">j</span> <span class="special">=</span> <span class="identifier">oN</span><span class="special">.</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">complain_and_0</span><span class="special">);</span> <span class="comment">// fun called</span> +<span class="identifier">assert</span> <span class="special">(</span><span class="identifier">i</span> <span class="special">==</span> <span class="number">0</span><span class="special">);</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_value_or_call_move"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">F</span> <span class="identifier">f</span><span class="special">)</span> <span class="special">&&</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code> + and <code class="computeroutput"><span class="identifier">F</span></code> models a <a href="http://www.sgi.com/tech/stl/Generator.html" target="_top"><code class="computeroutput"><span class="identifier">Generator</span></code></a> + whose result type is convertible to <code class="computeroutput"><span class="identifier">T</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">if</span> + <span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(**</span><span class="keyword">this</span><span class="special">);</span> <span class="keyword">else</span> <span class="keyword">return</span> + <span class="identifier">f</span><span class="special">();</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + ref-qualifiers on member functions this overload is not present. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_get_value_or_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_value_or</span><span class="special">(</span> + <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">&</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_value_or</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&</span> <span class="keyword">default</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">&</span> + <span class="identifier">get_optional_value_or</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">o</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span> <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get_optional_value_or</span> + <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>&</span> + <span class="identifier">o</span><span class="special">,</span> + <span class="identifier">T</span><span class="special">&</span> + <span class="keyword">default</span> <span class="special">)</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Deprecated:</strong></span> Use <code class="computeroutput"><span class="identifier">value_or</span><span class="special">()</span></code> instead. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> A reference to the contained + value, if any, or <code class="computeroutput"><span class="keyword">default</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">,</span> <span class="identifier">z</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span><span class="special">;</span> +<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">def</span><span class="special">.</span><span class="identifier">get_value_or</span><span class="special">(</span><span class="identifier">z</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">y</span> <span class="special">==</span> <span class="identifier">z</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">);</span> +<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">u</span> <span class="special">=</span> <span class="identifier">get_optional_value_or</span><span class="special">(</span><span class="identifier">opt</span><span class="special">,</span><span class="identifier">z</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">==</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">u</span> <span class="special">!=</span> <span class="identifier">z</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_get_ptr"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_ptr</span><span class="special">()</span> + <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">*</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span> + <span class="keyword">const</span><span class="special">*</span> + <span class="identifier">get_pointer</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">inline</span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">get_pointer</span> + <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> + <span class="special">&)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized, a pointer to the + contained value; else <code class="computeroutput"><span class="number">0</span></code> + (<span class="emphasis"><em>null</em></span>). + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The contained value is permanently + stored within <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>, + so you should not hold nor delete this pointer + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span> <span class="identifier">copt</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="identifier">T</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">opt</span><span class="special">.</span><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span> +<span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">cp</span> <span class="special">=</span> <span class="identifier">copt</span><span class="special">.</span><span class="identifier">get_ptr</span><span class="special">();</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">p</span> <span class="special">==</span> <span class="identifier">get_pointer</span><span class="special">(</span><span class="identifier">opt</span><span class="special">)</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">cp</span> <span class="special">==</span> <span class="identifier">get_pointer</span><span class="special">(</span><span class="identifier">copt</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_arrow"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> + <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span> <span class="special">->()</span> + <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">T</span><span class="special">*</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">>::</span><span class="keyword">operator</span> + <span class="special">->()</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> A pointer to the contained + value. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> Nothing. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> The requirement is asserted + via <code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">X</span> <span class="special">{</span> <span class="keyword">int</span> <span class="identifier">mdata</span> <span class="special">;</span> <span class="special">}</span> <span class="special">;</span> +<span class="identifier">X</span> <span class="identifier">x</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">X</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span><span class="identifier">x</span><span class="special">);</span> +<span class="identifier">opt</span><span class="special">-></span><span class="identifier">mdata</span> <span class="special">=</span> <span class="number">2</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_bool"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">explicit</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span> + <span class="keyword">bool</span><span class="special">()</span> + <span class="keyword">const</span> <span class="keyword">noexcept</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">!=</span> <span class="number">0</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> On compilers that do not support + explicit conversion operators this falls back to safe-bool idiom. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def</span> <span class="special">==</span> <span class="number">0</span> <span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">(</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt</span> <span class="special">!=</span> <span class="number">0</span> <span class="special">);</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_operator_not"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">noexcept</span> + <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized, <code class="computeroutput"><span class="keyword">true</span></code>; else <code class="computeroutput"><span class="keyword">false</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> This operator is provided for + those compilers which can't use the <span class="emphasis"><em>unspecified-bool-type + operator</em></span> in certain boolean contexts. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">opt</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">opt</span> <span class="special">);</span> +<span class="special">*</span><span class="identifier">opt</span> <span class="special">=</span> <span class="identifier">some_T</span> <span class="special">;</span> + +<span class="comment">// Notice the "double-bang" idiom here.</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!!</span><span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_optional_is_initialized"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">is_initialized</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Deprecated:</strong></span> Same as <code class="computeroutput"><span class="keyword">explicit</span> <span class="keyword">operator</span> + <span class="keyword">bool</span> <span class="special">()</span> + <span class="special">;</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<h6> +<a name="boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.h1"></a> + <span class="phrase"><a name="boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.free_functions"></a></span><a class="link" href="detailed_semantics.html#boost_optional.reference.header__boost_optional_optional_hpp_.detailed_semantics.free_functions">Free + functions</a> + </h6> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_make_optional_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="identifier">make_optional</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">v</span><span class="special">)</span></code> for the <span class="emphasis"><em>deduced</em></span> + type <code class="computeroutput"><span class="identifier">T</span></code> of <code class="computeroutput"><span class="identifier">v</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">foo</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> + +<span class="identifier">foo</span> <span class="special">(</span> <span class="identifier">make_optional</span><span class="special">(</span><span class="number">1</span><span class="special">+</span><span class="number">1</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// Creates an optional<int></span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_make_optional_bool_value"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">></span> <span class="identifier">make_optional</span><span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> + <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">condition</span><span class="special">,</span><span class="identifier">v</span><span class="special">)</span></code> for the <span class="emphasis"><em>deduced</em></span> + type <code class="computeroutput"><span class="identifier">T</span></code> of <code class="computeroutput"><span class="identifier">v</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">calculate_foo</span><span class="special">()</span> +<span class="special">{</span> + <span class="keyword">double</span> <span class="identifier">val</span> <span class="special">=</span> <span class="identifier">compute_foo</span><span class="special">();</span> + <span class="keyword">return</span> <span class="identifier">make_optional</span><span class="special">(</span><span class="identifier">is_not_nan_and_finite</span><span class="special">(</span><span class="identifier">val</span><span class="special">),</span><span class="identifier">val</span><span class="special">);</span> +<span class="special">}</span> + +<span class="identifier">optional</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">calculate_foo</span><span class="special">();</span> +<span class="keyword">if</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">v</span> <span class="special">)</span> + <span class="identifier">error</span><span class="special">(</span><span class="string">"foo wasn't computed"</span><span class="special">);</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">==</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + shall meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> If both <code class="computeroutput"><span class="identifier">x</span></code> + and <code class="computeroutput"><span class="identifier">y</span></code> are initialized, + <code class="computeroutput"><span class="special">(*</span><span class="identifier">x</span> + <span class="special">==</span> <span class="special">*</span><span class="identifier">y</span><span class="special">)</span></code>. + If only <code class="computeroutput"><span class="identifier">x</span></code> or <code class="computeroutput"><span class="identifier">y</span></code> is initialized, <code class="computeroutput"><span class="keyword">false</span></code>. + If both are uninitialized, <code class="computeroutput"><span class="keyword">true</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> This definition guarantees + that <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> + not containing a value is compared unequal to any <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> containing any value, and equal + to any other <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> not containing a value. Pointers + have shallow relational operators while <code class="computeroutput"><span class="identifier">optional</span></code> + has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special">==</span></code> directly in generic code which expect + to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> or a pointer; use <a href="../../../../../../utility/OptionalPointee.html#equal" target="_top"><code class="computeroutput"><span class="identifier">equal_pointees</span><span class="special">()</span></code></a> + instead + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">)),</span> <span class="identifier">o1_</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o2</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">));</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN</span> <span class="special">);</span> <span class="comment">// Identity implies equality</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">//</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN_</span> <span class="special">);</span> <span class="comment">// Both uninitialized compare equal</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">!=</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">// Initialized unequal to initialized.</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1_</span> <span class="special">);</span> <span class="comment">// Both initialized compare as (*lhs == *rhs)</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">!=</span> <span class="identifier">o2</span> <span class="special">);</span> <span class="comment">//</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_less_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special"><</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> Expression <code class="computeroutput"><span class="special">*</span><span class="identifier">x</span> <span class="special"><</span> <span class="special">*</span><span class="identifier">y</span></code> shall be well-formed and its result + shall be convertible to <code class="computeroutput"><span class="keyword">bool</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">(!</span><span class="identifier">y</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">false</span> <span class="special">:</span> <span class="special">(!</span><span class="identifier">x</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">true</span> <span class="special">:</span> <span class="special">*</span><span class="identifier">x</span> <span class="special"><</span> + <span class="special">*</span><span class="identifier">y</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> This definition guarantees + that <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> + not containing a value is ordered as less than any <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> containing any value, and equivalent + to any other <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> not containing a value. Pointers + have shallow relational operators while <code class="computeroutput"><span class="identifier">optional</span></code> + has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> directly in generic code which + expect to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> or a pointer; use <a href="../../../../../../utility/OptionalPointee.html#less" target="_top"><code class="computeroutput"><span class="identifier">less_pointees</span><span class="special">()</span></code></a> + instead. <code class="computeroutput"><span class="identifier">T</span></code> need not + be <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>. Only + single <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> + is required. Other relational operations are defined in terms of this + one. If <code class="computeroutput"><span class="identifier">T</span></code>'s <code class="computeroutput"><span class="keyword">operator</span><span class="special"><</span></code> + satisfies the axioms of <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a> (transitivity, + antisymmetry and irreflexivity), <code class="computeroutput"><span class="identifier">optinal</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> is <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o0</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">0</span><span class="special">));</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Identity implies equivalence</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o1</span> <span class="special"><</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">);</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">oN_</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Two uninitialized are equivalent</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN_</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special"><</span> <span class="identifier">o0</span> <span class="special">);</span> <span class="comment">// Uninitialized is less than initialized</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o0</span> <span class="special"><</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> + +<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special"><</span> <span class="identifier">o2</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// Two initialized compare as (*lhs < *rhs)</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special"><</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special"><</span> <span class="identifier">o2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span> +</pre> + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_not_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">!=</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> + <span class="identifier">x</span> <span class="special">==</span> + <span class="identifier">y</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_greater_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">></span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">(</span> + <span class="identifier">y</span> <span class="special"><</span> + <span class="identifier">x</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_less_or_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special"><=</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> + <span class="identifier">y</span> <span class="special"><</span> + <span class="identifier">x</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_greater_or_equal_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">>=</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">);</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> + <span class="identifier">x</span> <span class="special"><</span> + <span class="identifier">y</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_equal_optional_none"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">==</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> <span class="special">)</span> + <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">==</span> <span class="special">(</span> + <span class="identifier">none_t</span><span class="special">,</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">!</span><span class="identifier">x</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + need not meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_operator_compare_not_equal_optional_none"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">!=</span> <span class="special">(</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> <span class="special">)</span> + <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span> + <span class="special">!=</span> <span class="special">(</span> + <span class="identifier">none_t</span><span class="special">,</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span> + <span class="identifier">x</span> <span class="special">==</span> + <span class="identifier">y</span> <span class="special">);</span></code> + </li></ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> + </p> +<a name="reference_swap_optional_optional"></a><div class="blockquote"><blockquote class="blockquote"><p> + <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">swap</span> + <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">y</span> + <span class="special">)</span> <span class="special">;</span></code> + </p></blockquote></div> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> Lvalues of type <code class="computeroutput"><span class="identifier">T</span></code> shall be swappable and <code class="computeroutput"><span class="identifier">T</span></code> shall be <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>. + </li> +<li class="listitem"> +<p class="simpara"> + <span class="bold"><strong>Effects:</strong></span> + </p> +<div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<thead><tr> +<th> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value + </p> + </th> +<th> + <p> + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + does not contain a value + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + calls <code class="computeroutput"><span class="identifier">swap</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">),</span> <span class="special">*</span><span class="identifier">rhs</span><span class="special">)</span></code> + </p> + </td> +<td> + <p> + initializes the contained value of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> as if direct-initializing + an object of type <code class="computeroutput"><span class="identifier">T</span></code> + with the expression <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code>, followed by <code class="computeroutput"><span class="identifier">rhs</span><span class="special">.</span><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, + <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> + contains a value and <code class="computeroutput"><span class="identifier">rhs</span></code> + does not contain a value + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">rhs</span></code> does + not contain a value + </p> + </td> +<td> + <p> + initializes the contained value of <code class="computeroutput"><span class="identifier">rhs</span></code> + as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code> with the expression + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">))</span></code>, + followed by <code class="computeroutput"><span class="identifier">val</span><span class="special">-></span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> does not contain a value + and <code class="computeroutput"><span class="identifier">rhs</span></code> contains + a value + </p> + </td> +<td> + <p> + no effect + </p> + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> + <span class="bold"><strong>Postconditions:</strong></span> The states of <code class="computeroutput"><span class="identifier">x</span></code> and <code class="computeroutput"><span class="identifier">y</span></code> + interchanged. + </li> +<li class="listitem"> + <span class="bold"><strong>Throws:</strong></span> If both are initialized, whatever + <code class="computeroutput"><span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&,</span><span class="identifier">T</span><span class="special">&)</span></code> + throws. If only one is initialized, whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="special">)</span></code> + throws. + </li> +<li class="listitem"> + <span class="bold"><strong>Example:</strong></span> +<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">(</span><span class="number">12</span><span class="special">);</span> +<span class="identifier">T</span> <span class="identifier">y</span><span class="special">(</span><span class="number">21</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def0</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">def1</span> <span class="special">;</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">optX</span><span class="special">(</span><span class="identifier">x</span><span class="special">);</span> +<span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">optY</span><span class="special">(</span><span class="identifier">y</span><span class="special">);</span> + +<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">def1</span><span class="special">);</span> <span class="comment">// no-op</span> + +<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">optX</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">def0</span> <span class="special">==</span> <span class="identifier">x</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!</span><span class="identifier">optX</span> <span class="special">);</span> + +<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">def0</span><span class="special">,</span><span class="identifier">optX</span><span class="special">);</span> <span class="comment">// Get back to original values</span> + +<span class="identifier">boost</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">optX</span><span class="special">,</span><span class="identifier">optY</span><span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">y</span> <span class="special">);</span> +<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">optY</span> <span class="special">==</span> <span class="identifier">x</span> <span class="special">);</span> +</pre> + </li> +</ul></div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../optional/reference/header__boost_optional_optional_hpp_.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../header__boost_optional_hpp_.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/io_header.html b/libs/optional/doc/html/boost_optional/reference/io_header.html new file mode 100644 index 000000000..c61e5c6c8 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/io_header.html @@ -0,0 +1,72 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Header <boost/optional/optional_io.hpp></title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/reference.html" title="Reference"> +<link rel="prev" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html" title="Detailed semantics"> +<link rel="next" href="io_header/io_semantics.html" title="Detailed semantics"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" 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+</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.reference.io_header"></a><a class="link" href="io_header.html" title="Header <boost/optional/optional_io.hpp>">Header <boost/optional/optional_io.hpp></a> +</h3></div></div></div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.io_header.io_synop"></a><a class="link" href="io_header.html#boost_optional.reference.io_header.io_synop" title="Synopsis">Synopsis</a> +</h4></div></div></div> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">istream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">ostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">/</span><span class="identifier">optional</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> + +<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> + <span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span><span class="special">);</span> <a class="link" href="io_header/io_semantics.html#reference_operator_ostream"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> + + <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> + <span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">none_t</span> <span class="keyword">const</span><span class="special">&);</span> <a class="link" href="io_header/io_semantics.html#reference_operator_ostream_none"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> + +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> + <span class="keyword">operator</span><span class="special">>>(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> <span class="identifier">in</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">v</span><span class="special">);</span> <a class="link" href="io_header/io_semantics.html#reference_operator_istream"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> + +<span class="special">}</span> <span class="comment">// namespace boost</span> +</pre> +<p> + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="io_header/io_semantics.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/io_header/io_semantics.html b/libs/optional/doc/html/boost_optional/reference/io_header/io_semantics.html new file mode 100644 index 000000000..c368ac728 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/reference/io_header/io_semantics.html @@ -0,0 +1,112 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Detailed semantics</title> +<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../../index.html" title="Boost.Optional"> +<link rel="up" href="../io_header.html" title="Header <boost/optional/optional_io.hpp>"> +<link rel="prev" href="../io_header.html" title="Header <boost/optional/optional_io.hpp>"> +<link rel="next" href="../header__boost_optional_optional_fwd_hpp_.html" title="Header <boost/optional/optional_fwd.hpp>"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../io_header.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_header.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../header__boost_optional_optional_fwd_hpp_.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boost_optional.reference.io_header.io_semantics"></a><a class="link" href="io_semantics.html" title="Detailed semantics">Detailed + semantics</a> +</h4></div></div></div> +<p> + <a name="reference_operator_ostream"></a><code class="computeroutput"><span class="keyword">template</span> + <span class="special"><</span><span class="keyword">class</span> + <span class="identifier">CharType</span><span class="special">,</span> + <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span></code> + <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span></code> <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> + <span class="identifier">out</span><span class="special">,</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span><span class="special">);</span></code> + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Outputs an implementation-defined + string. The output contains the information about whether the optional + object contains a value or not. If <code class="computeroutput"><span class="identifier">v</span></code> + contains a value, the output contains result of calling <code class="computeroutput"><span class="identifier">out</span> <span class="special"><<</span> + <span class="special">*</span><span class="identifier">v</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="identifier">out</span></code>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> <a name="reference_operator_ostream_none"></a> + </p> +<p> + <code class="computeroutput"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> + <span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span></code> <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span></code> + <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">none_t</span><span class="special">);</span></code> + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Outputs an implementation-defined + string. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="identifier">out</span></code>. + </li> +</ul></div> +<p> + <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span> <a name="reference_operator_istream"></a> + </p> +<p> + <code class="computeroutput"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> + <span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span></code> <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span></code> + <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special">>>(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special"><</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">>&</span> <span class="identifier">in</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">v</span><span class="special">);</span></code> + </p> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> + is <a href="http://www.sgi.com/tech/stl/DefaultConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">DefaultConstructible</span></code></a> and + <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>. + </li> +<li class="listitem"> + <span class="bold"><strong>Effect:</strong></span> Reads the value of optional + object from <code class="computeroutput"><span class="identifier">in</span></code>. If + the string representation indicates that the optional object should + contain a value, <code class="computeroutput"><span class="identifier">v</span></code> + contains a value and its contained value is obtained as if by default-constructing + an object <code class="computeroutput"><span class="identifier">o</span></code> of type + <code class="computeroutput"><span class="identifier">T</span></code> and then calling + <code class="computeroutput"><span class="identifier">in</span> <span class="special">>></span> + <span class="identifier">o</span></code>; otherwise <code class="computeroutput"><span class="identifier">v</span></code> does not contain a value, and the + previously contained value (if any) has been destroyed. + </li> +<li class="listitem"> + <span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="identifier">out</span></code>. + </li> +</ul></div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../io_header.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_header.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../header__boost_optional_optional_fwd_hpp_.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/reference/synopsis.html b/libs/optional/doc/html/boost_optional/reference/synopsis.html deleted file mode 100644 index 99adcfddd..000000000 --- a/libs/optional/doc/html/boost_optional/reference/synopsis.html +++ /dev/null @@ -1,174 +0,0 @@ -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> -<title>Synopsis</title> -<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> -<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> -<link rel="home" href="../../index.html" title="Chapter 1. Boost.Optional"> -<link rel="up" href="../../optional/reference.html" title="Reference"> -<link rel="prev" href="../../optional/reference.html" title="Reference"> -<link rel="next" href="detailed_semantics.html" title="Detailed Semantics"> -</head> -<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> -<table cellpadding="2" width="100%"><tr> -<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> -<td align="center"><a href="../../../../../../index.html">Home</a></td> -<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> -<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> -<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> -<td align="center"><a href="../../../../../../more/index.htm">More</a></td> -</tr></table> -<hr> -<div class="spirit-nav"> -<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="detailed_semantics.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> -</div> -<div class="section"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="boost_optional.reference.synopsis"></a><a class="link" href="synopsis.html" title="Synopsis">Synopsis</a> -</h3></div></div></div> -<pre class="programlisting"><code class="computeroutput"><span class="comment">// In Header: <</span></code><a href="../../../../../../boost/optional/optional.hpp" target="_top">boost/optional/optional.hpp</a><span class="comment">></span> - -<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> -<span class="keyword">class</span> <span class="identifier">optional</span> -<span class="special">{</span> - <span class="keyword">public</span> <span class="special">:</span> - - <span class="comment">// (If T is of reference type, the parameters and results by reference are by value)</span> - - <span class="identifier">optional</span> <span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_none_t"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_move_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="comment">// [new in 1.34]</span> - <span class="identifier">optional</span> <span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_bool_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">optional</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="emphasis"><em>see below</em></span><span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_move_constructor_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_other_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_move_constructor_other_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">InPlaceFactory</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">InPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_factory"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">TypedInPlaceFactory</span><span class="special">></span> <span class="keyword">explicit</span> <span class="identifier">optional</span> <span class="special">(</span> <span class="identifier">TypedInPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_constructor_factory"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_none_t"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_move_equal_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="emphasis"><em>see below</em></span><span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_move_equal_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_other_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">>&&</span> <span class="identifier">rhs</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_move_equal_other_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span><span class="special">...</span> <span class="identifier">Args</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">emplace</span> <span class="special">(</span> <span class="identifier">Args</span><span class="special">...&&</span> <span class="identifier">args</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_emplace"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">InPlaceFactory</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">InPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_factory"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">TypedInPlaceFactory</span><span class="special">></span> <span class="identifier">optional</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">=</span> <span class="special">(</span> <span class="identifier">TypedInPlaceFactory</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">f</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_equal_factory"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">get</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span><span class="special">()</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="keyword">operator</span> <span class="special">->()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_arrow"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">*</span> <span class="keyword">operator</span> <span class="special">->()</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_arrow"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_asterisk"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">&</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="special">&;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_asterisk"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">&&</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="special">&&;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_asterisk"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">&</span> <span class="identifier">value</span><span class="special">()</span> <span class="special">&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">&&</span> <span class="identifier">value</span><span class="special">()</span> <span class="special">&&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">value_or</span><span class="special">(</span> <span class="identifier">U</span> <span class="special">&&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_value_or"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">></span> <span class="identifier">T</span> <span class="identifier">value_or</span><span class="special">(</span> <span class="identifier">U</span> <span class="special">&&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">&&</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_value_or"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">get_ptr</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - <span class="identifier">T</span><span class="special">*</span> <span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_bool"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_operator_not"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="comment">// deprecated methods</span> - - <span class="comment">// (deprecated)</span> - <span class="keyword">void</span> <span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_reset"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="comment">// (deprecated)</span> - <span class="keyword">void</span> <span class="identifier">reset</span> <span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_reset_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="comment">// (deprecated)</span> - <span class="keyword">bool</span> <span class="identifier">is_initialized</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_is_initialized"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - - <span class="comment">// (deprecated)</span> - <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">get_value_or</span><span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span> <span class="special">)</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_value_or_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> -<span class="special">};</span> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">==</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_equal_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_not_equal_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special"><</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_less_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">></span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_greater_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special"><=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_less_or_equal_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">>=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_greater_or_equal_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">==</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_equal_optional_none"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">bool</span> <span class="keyword">operator</span> <span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span> <span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_operator_compare_not_equal_optional_none"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">make_optional</span> <span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_make_optional_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">make_optional</span> <span class="special">(</span> <span class="keyword">bool</span> <span class="identifier">condition</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_make_optional_bool_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">get_optional_value_or</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">opt</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="keyword">default</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_value_or_value"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">get</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>*</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">get_pointer</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">get_pointer</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">&</span> <span class="identifier">opt</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">inline</span> <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span> <span class="identifier">y</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics.html#reference_swap_optional_optional"><span class="inlinemediaobject"><img src="../../images/callouts/R.png" alt="R"></span></a> - -<span class="special">}</span> <span class="comment">// namespace boost</span> -</pre> -</div> -<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> -<td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> - Distributed under the Boost Software License, Version 1.0. (See accompanying - file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) - </p> -</div></td> -</tr></table> -<hr> -<div class="spirit-nav"> -<a accesskey="p" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="detailed_semantics.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> -</div> -</body> -</html> diff --git a/libs/optional/doc/html/boost_optional/relnotes.html b/libs/optional/doc/html/boost_optional/relnotes.html new file mode 100644 index 000000000..3fb495b3a --- /dev/null +++ b/libs/optional/doc/html/boost_optional/relnotes.html @@ -0,0 +1,144 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Release Notes</title> +<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../index.html" title="Boost.Optional"> +<link rel="up" href="../index.html" title="Boost.Optional"> +<link rel="prev" href="dependencies_and_portability/optional_reference_binding.html" title="Optional Reference Binding"> +<link rel="next" href="acknowledgements.html" title="Acknowledgements"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> +<td align="center"><a href="../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledgements.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="boost_optional.relnotes"></a><a class="link" href="relnotes.html" title="Release Notes">Release Notes</a> +</h2></div></div></div> +<h4> +<a name="boost_optional.relnotes.h0"></a> + <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_58"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_58">Boost + Release 1.58</a> + </h4> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none_t</span></code> is no longer convertible from + literal <code class="computeroutput"><span class="number">0</span></code>. This avoids a bug + where <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">rational</span><span class="special"><</span><span class="keyword">int</span><span class="special">>></span> <span class="identifier">oi</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></code> would + initialize an optional object with no contained value. + </li> +<li class="listitem"> + Improved the trick that prevents streaming out <code class="computeroutput"><span class="identifier">optional</span></code> + without header <code class="computeroutput"><span class="identifier">optional_io</span><span class="special">.</span><span class="identifier">hpp</span></code> + by using safe-bool idiom. This addresses <a href="https://svn.boost.org/trac/boost/ticket/10825" target="_top">Trac + #10825</a> + </li> +<li class="listitem"> + IOStream operators are now mentioned in documentation. + </li> +<li class="listitem"> + Added a way to manually disable move semantics: just define macro <code class="computeroutput"><span class="identifier">BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES</span></code>. + This can be used to work around <a href="https://svn.boost.org/trac/boost/ticket/10399" target="_top">Trac + #10399</a> + </li> +<li class="listitem"> + It is no longer possible to assign <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span></code> to <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> when <code class="computeroutput"><span class="identifier">U</span></code> + is not assignable or convertible to <code class="computeroutput"><span class="identifier">T</span></code> + (<a href="https://svn.boost.org/trac/boost/ticket/11087" target="_top">Trac #11087</a>). + </li> +<li class="listitem"> + Value accessors now work correctly on rvalues of <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">&></span></code> (<a href="https://svn.boost.org/trac/boost/ticket/10839" target="_top">Trac + #10839</a>). + </li> +</ul></div> +<h4> +<a name="boost_optional.relnotes.h1"></a> + <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_57"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_57">Boost + Release 1.57</a> + </h4> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> + <a href="https://github.com/boostorg/optional/pull/9" target="_top">Git pull #9</a>: + <span class="emphasis"><em>"Supply <code class="computeroutput"><span class="special"><</span><span class="identifier">string</span><span class="special">></span></code> + to fix C++03 compile error on <code class="computeroutput"><span class="identifier">logic_error</span><span class="special">(</span><span class="string">"..."</span><span class="special">)</span></code>"</em></span>. + </li></ul></div> +<h4> +<a name="boost_optional.relnotes.h2"></a> + <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_56"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_56">Boost + Release 1.56</a> + </h4> +<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> +<li class="listitem"> + Added support for rvalue references. Now <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> works with moveable but non-copyable + <code class="computeroutput"><span class="identifier">T</span></code>'s, + </li> +<li class="listitem"> + Improved <code class="computeroutput"><span class="identifier">swap</span></code> (now uses + move operations), + </li> +<li class="listitem"> + Added function <code class="computeroutput"><span class="identifier">emplace</span><span class="special">()</span></code>. This is the last of the requests from + <a href="https://svn.boost.org/trac/boost/ticket/1841" target="_top">Trac #1841</a>, + </li> +<li class="listitem"> + <code class="computeroutput"><span class="identifier">optional</span></code> is moveable, including + conditional <code class="computeroutput"><span class="keyword">noexcept</span></code> specifications, + which make it <code class="computeroutput"><span class="identifier">move_if_noexcept</span></code>-friendly, + </li> +<li class="listitem"> + Using explicit operator bool() on platforms that support it (<a href="https://svn.boost.org/trac/boost/ticket/4227" target="_top">Trac + #4227</a>) (breaking change), + </li> +<li class="listitem"> + Forward declaration of <code class="computeroutput"><span class="keyword">operator</span><span class="special"><<(</span><span class="identifier">ostream</span><span class="special">&,</span> <span class="identifier">optional</span> + <span class="keyword">const</span><span class="special">&)</span></code> + to prevent inadvertent incorrect serialization of optional objects, + </li> +<li class="listitem"> + Removed deprecated function <code class="computeroutput"><span class="identifier">reset</span><span class="special">()</span></code> from examples (<a href="https://svn.boost.org/trac/boost/ticket/9005" target="_top">Trac + #9005</a>), + </li> +<li class="listitem"> + Equality comparison with <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> + does not require that <code class="computeroutput"><span class="identifier">T</span></code> + be EqualityComparable, + </li> +<li class="listitem"> + Optional rvalue references are explicitly disallowed, + </li> +<li class="listitem"> + Binding temporaries to optional references is explicitly disallowed (breaking + change), + </li> +<li class="listitem"> + More ways to access the contained value, functions <code class="computeroutput"><span class="identifier">value</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">value_or</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">value_or_eval</span><span class="special">()</span></code>, + </li> +<li class="listitem"> + Updated and reorganized documentation, added tutorial and quick guide sections. + </li> +</ul></div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="dependencies_and_portability/optional_reference_binding.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledgements.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/a_note_about_optional_bool_.html b/libs/optional/doc/html/boost_optional/tutorial/a_note_about_optional_bool_.html index ea3618b87..def5bbfd2 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/a_note_about_optional_bool_.html +++ b/libs/optional/doc/html/boost_optional/tutorial/a_note_about_optional_bool_.html @@ -94,7 +94,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/design_overview.html b/libs/optional/doc/html/boost_optional/tutorial/design_overview.html index d6598bca6..cc5e3b467 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/design_overview.html +++ b/libs/optional/doc/html/boost_optional/tutorial/design_overview.html @@ -170,7 +170,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_interface.html b/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_interface.html index 984ae4bf1..c3833ffb8 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_interface.html +++ b/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_interface.html @@ -63,8 +63,8 @@ </p> <h6> <a name="boost_optional.tutorial.design_overview.the_interface.h0"></a> - <span class="phrase"><a name="boost_optional.tutorial.design_overview.the_interface.lexically_hinted_value_access_in_the_presence_of_possibly_untitialized_optional_objects__the_operators___and___gt_"></a></span><a class="link" href="the_interface.html#boost_optional.tutorial.design_overview.the_interface.lexically_hinted_value_access_in_the_presence_of_possibly_untitialized_optional_objects__the_operators___and___gt_">Lexically-hinted - Value Access in the presence of possibly untitialized optional objects: + <span class="phrase"><a name="boost_optional.tutorial.design_overview.the_interface.lexically_hinted_value_access_in_the_presence_of_possibly_uninitialized_optional_objects__the_operators___and___gt_"></a></span><a class="link" href="the_interface.html#boost_optional.tutorial.design_overview.the_interface.lexically_hinted_value_access_in_the_presence_of_possibly_uninitialized_optional_objects__the_operators___and___gt_">Lexically-hinted + Value Access in the presence of possibly uninitialized optional objects: The operators * and -></a> </h6> <p> @@ -173,7 +173,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_semantics.html b/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_semantics.html index 5dbc63b32..9a38fefe8 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_semantics.html +++ b/libs/optional/doc/html/boost_optional/tutorial/design_overview/the_semantics.html @@ -107,7 +107,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/exception_safety_guarantees.html b/libs/optional/doc/html/boost_optional/tutorial/exception_safety_guarantees.html index ea3fa8f5e..dfa34c85c 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/exception_safety_guarantees.html +++ b/libs/optional/doc/html/boost_optional/tutorial/exception_safety_guarantees.html @@ -161,7 +161,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/in_place_factories.html b/libs/optional/doc/html/boost_optional/tutorial/in_place_factories.html index d6907b9e3..4cfef3256 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/in_place_factories.html +++ b/libs/optional/doc/html/boost_optional/tutorial/in_place_factories.html @@ -183,7 +183,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/io_operators.html b/libs/optional/doc/html/boost_optional/tutorial/io_operators.html new file mode 100644 index 000000000..8443a4922 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/tutorial/io_operators.html @@ -0,0 +1,87 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>IO operators</title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/tutorial.html" title="Tutorial"> +<link rel="prev" href="relational_operators.html" title="Relational operators"> +<link rel="next" href="optional_references.html" title="Optional references"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="relational_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.tutorial.io_operators"></a><a class="link" href="io_operators.html" title="IO operators">IO operators</a> +</h3></div></div></div> +<p> + It is possible to use <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> + with IO streams, provided that <code class="computeroutput"><span class="identifier">T</span></code> + can be used with streams. IOStream operators are defined in a separate header. + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">/</span><span class="identifier">optional_io</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">o1</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">oN</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">o1</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cin</span> <span class="special">>></span> <span class="identifier">oN</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +<p> + The current implementation does not guarantee any particular output. What + it guarantees is that if streaming out and then back in <code class="computeroutput"><span class="identifier">T</span></code> + gives the same value, then streaming out and then back in <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> + will also give back the same result: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">sstream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">/</span><span class="identifier">optional_io</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">o1</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">oN</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span><span class="special">;</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">x1</span><span class="special">,</span> <span class="identifier">x2</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">stringstream</span> <span class="identifier">s</span><span class="special">;</span> + <span class="identifier">s</span> <span class="special"><<</span> <span class="identifier">o1</span> <span class="special"><<</span> <span class="identifier">oN</span><span class="special">;</span> + <span class="identifier">s</span> <span class="special">>></span> <span class="identifier">x1</span> <span class="special">>></span> <span class="identifier">x2</span><span class="special">;</span> + <span class="identifier">assert</span> <span class="special">(</span><span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">x1</span><span class="special">);</span> + <span class="identifier">assert</span> <span class="special">(</span><span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">x2</span><span class="special">);</span> +<span class="special">}</span> +</pre> +<p> + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="relational_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/optional_references.html b/libs/optional/doc/html/boost_optional/tutorial/optional_references.html index 4e067c2d9..13209411f 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/optional_references.html +++ b/libs/optional/doc/html/boost_optional/tutorial/optional_references.html @@ -6,7 +6,7 @@ <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../index.html" title="Boost.Optional"> <link rel="up" href="../../optional/tutorial.html" title="Tutorial"> -<link rel="prev" href="relational_operators.html" title="Relational operators"> +<link rel="prev" href="io_operators.html" title="IO operators"> <link rel="next" href="rebinding_semantics_for_assignment_of_optional_references.html" title="Rebinding semantics for assignment of optional references"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> @@ -20,7 +20,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="relational_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rebinding_semantics_for_assignment_of_optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="io_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rebinding_semantics_for_assignment_of_optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> @@ -101,7 +101,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -109,7 +109,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="relational_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rebinding_semantics_for_assignment_of_optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="io_operators.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rebinding_semantics_for_assignment_of_optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/performance_considerations.html b/libs/optional/doc/html/boost_optional/tutorial/performance_considerations.html new file mode 100644 index 000000000..2e2d4ca72 --- /dev/null +++ b/libs/optional/doc/html/boost_optional/tutorial/performance_considerations.html @@ -0,0 +1,223 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Performance considerations</title> +<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../../index.html" title="Boost.Optional"> +<link rel="up" href="../../optional/tutorial.html" title="Tutorial"> +<link rel="prev" href="type_requirements.html" title="Type requirements"> +<link rel="next" href="../../optional/reference.html" title="Reference"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> +<td align="center"><a href="../../../../../../index.html">Home</a></td> +<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="type_requirements.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="boost_optional.tutorial.performance_considerations"></a><a class="link" href="performance_considerations.html" title="Performance considerations">Performance + considerations</a> +</h3></div></div></div> +<p> + Technical details aside, the memory layout of <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> + is more-less this: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">optional</span> +<span class="special">{</span> + <span class="keyword">bool</span> <span class="identifier">_initialized</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">aligned_storage_t</span><span class="special"><</span><span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">t</span><span class="special">),</span> <span class="keyword">alignof</span><span class="special">(</span><span class="identifier">T</span><span class="special">)></span> <span class="identifier">_storage</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + But for the purpose of this analysis, considering memory layouts, we can + think of it as: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">optional</span> +<span class="special">{</span> + <span class="keyword">bool</span> <span class="identifier">_initialized</span><span class="special">;</span> + <span class="identifier">T</span> <span class="identifier">_storage</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + Given type <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code>, and + assuming that <code class="computeroutput"><span class="keyword">sizeof</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> <span class="special">==</span> + <span class="number">4</span></code>, we will get <code class="computeroutput"><span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">>)</span> + <span class="special">==</span> <span class="number">8</span></code>. + This is so because of the alignment rules, for our two members we get the + following alignment: + </p> +<p> + <span class="inlinemediaobject"><img src="../../images/opt_align1.png" alt="opt_align1"></span> + </p> +<p> + This means you can fit twice as many <code class="computeroutput"><span class="keyword">int</span></code>s + as <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code>s into + the same space of memory. Therefore, if the size of the objects is critical + for your application (e.g., because you want to utilize your CPU cache in + order to gain performance) and you have determined you are willing to trade + the code clarity, it is recommended that you simply go with type <code class="computeroutput"><span class="keyword">int</span></code> and use some 'magic value' to represent + <span class="emphasis"><em>not-an-int</em></span>. + </p> +<p> + Even if you cannot spare any value of <code class="computeroutput"><span class="keyword">int</span></code> + to represent <span class="emphasis"><em>not-an-int</em></span> (e.g., because every value is + useful, or you do want to signal <span class="emphasis"><em>not-an-int</em></span> explicitly), + at least for <code class="computeroutput"><span class="identifier">Trivial</span></code> types + you should consider storing the value and the <code class="computeroutput"><span class="keyword">bool</span></code> + flag representing the <span class="emphasis"><em>null-state</em></span> separately. Consider + the following class: + </p> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Record</span> +<span class="special">{</span> + <span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">_min</span><span class="special">;</span> + <span class="identifier">optional</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">_max</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + Its memory layout can be depicted as follows: + </p> +<p> + <span class="inlinemediaobject"><img src="../../images/opt_align2.png" alt="opt_align2"></span> + </p> +<p> + This is exactly the same as if we had the following members: + </p> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Record</span> +<span class="special">{</span> + <span class="keyword">bool</span> <span class="identifier">_has_min</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">_min</span><span class="special">;</span> + <span class="keyword">bool</span> <span class="identifier">_has_max</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">_max</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + But when they are stored separately, we at least have an option to reorder + them like this: + </p> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Record</span> +<span class="special">{</span> + <span class="keyword">bool</span> <span class="identifier">_has_min</span><span class="special">;</span> + <span class="keyword">bool</span> <span class="identifier">_has_max</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">_min</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">_max</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + Which gives us the following layout (and smaller total size): + </p> +<p> + <span class="inlinemediaobject"><img src="../../images/opt_align3.png" alt="opt_align3"></span> + </p> +<p> + Sometimes it requires detailed consideration what data we make optional. + In our case above, if we determine that both minimum and maximum value can + be provided or not provided together, but one is never provided without the + other, we can make only one optional memebr: + </p> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Limits</span> +<span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">_min</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">_max</span><span class="special">;</span> +<span class="special">};</span> + +<span class="keyword">struct</span> <span class="identifier">Record</span> +<span class="special">{</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">Limits</span><span class="special">></span> <span class="identifier">_limits</span><span class="special">;</span> +<span class="special">};</span> +</pre> +<p> + This would give us the following layout: + </p> +<p> + <span class="inlinemediaobject"><img src="../../images/opt_align4.png" alt="opt_align4"></span> + </p> +<h5> +<a name="boost_optional.tutorial.performance_considerations.h0"></a> + <span class="phrase"><a name="boost_optional.tutorial.performance_considerations.optional_function_parameters"></a></span><a class="link" href="performance_considerations.html#boost_optional.tutorial.performance_considerations.optional_function_parameters">Optional + function parameters</a> + </h5> +<p> + Having function parameters of type <code class="computeroutput"><span class="keyword">const</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">>&</span></code> + may incur certain unexpected run-time cost connected to copy construction + of <code class="computeroutput"><span class="identifier">T</span></code>. Consider the following + code. + </p> +<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">fun</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">optional</span><span class="special"><</span><span class="identifier">Big</span><span class="special">>&</span> <span class="identifier">v</span><span class="special">)</span> +<span class="special">{</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">v</span><span class="special">)</span> <span class="identifier">doSomethingWith</span><span class="special">(*</span><span class="identifier">v</span><span class="special">);</span> + <span class="keyword">else</span> <span class="identifier">doSomethingElse</span><span class="special">();</span> +<span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">Big</span><span class="special">></span> <span class="identifier">ov</span><span class="special">;</span> + <span class="identifier">Big</span> <span class="identifier">v</span><span class="special">;</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">none</span><span class="special">);</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">ov</span><span class="special">);</span> <span class="comment">// no copy</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> <span class="comment">// copy constructor of Big</span> +<span class="special">}</span> +</pre> +<p> + No copy elision or move semantics can save us from copying type <code class="computeroutput"><span class="identifier">Big</span></code> here. Not that we need any copy, but + this is how <code class="computeroutput"><span class="identifier">optional</span></code> works. + In order to avoid copying in this case, one could provide second overload + of <code class="computeroutput"><span class="identifier">fun</span></code>: + </p> +<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">fun</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Big</span><span class="special">&</span> <span class="identifier">v</span><span class="special">)</span> +<span class="special">{</span> + <span class="identifier">doSomethingWith</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> +<span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">Big</span><span class="special">></span> <span class="identifier">ov</span><span class="special">;</span> + <span class="identifier">Big</span> <span class="identifier">v</span><span class="special">;</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">ov</span><span class="special">);</span> <span class="comment">// no copy</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> <span class="comment">// no copy: second overload selected</span> +<span class="special">}</span> +</pre> +<p> + Alternatively, you could consider using an optional reference instead: + </p> +<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">fun</span><span class="special">(</span><span class="identifier">optional</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">Big</span><span class="special">&></span> <span class="identifier">v</span><span class="special">)</span> <span class="comment">// note where the reference is</span> +<span class="special">{</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">v</span><span class="special">)</span> <span class="identifier">doSomethingWith</span><span class="special">(*</span><span class="identifier">v</span><span class="special">);</span> + <span class="keyword">else</span> <span class="identifier">doSomethingElse</span><span class="special">();</span> +<span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">optional</span><span class="special"><</span><span class="identifier">Big</span><span class="special">></span> <span class="identifier">ov</span><span class="special">;</span> + <span class="identifier">Big</span> <span class="identifier">v</span><span class="special">;</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">none</span><span class="special">);</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">ov</span><span class="special">);</span> <span class="comment">// doesn't compile</span> + <span class="identifier">fun</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> <span class="comment">// no copy</span> +<span class="special">}</span> +</pre> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="type_requirements.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/rebinding_semantics_for_assignment_of_optional_references.html b/libs/optional/doc/html/boost_optional/tutorial/rebinding_semantics_for_assignment_of_optional_references.html index 26bbf6600..a4c566ffc 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/rebinding_semantics_for_assignment_of_optional_references.html +++ b/libs/optional/doc/html/boost_optional/tutorial/rebinding_semantics_for_assignment_of_optional_references.html @@ -135,7 +135,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> diff --git a/libs/optional/doc/html/boost_optional/tutorial/relational_operators.html b/libs/optional/doc/html/boost_optional/tutorial/relational_operators.html index bc97e7b72..31914272a 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/relational_operators.html +++ b/libs/optional/doc/html/boost_optional/tutorial/relational_operators.html @@ -7,7 +7,7 @@ <link rel="home" href="../../index.html" title="Boost.Optional"> <link rel="up" href="../../optional/tutorial.html" title="Tutorial"> <link rel="prev" href="when_to_use_optional.html" title="When to use Optional"> -<link rel="next" href="optional_references.html" title="Optional references"> +<link rel="next" href="io_operators.html" title="IO operators"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> @@ -20,7 +20,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="when_to_use_optional.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="when_to_use_optional.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="io_operators.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> @@ -30,7 +30,7 @@ <p> Type <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> is <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a> whenever <code class="computeroutput"><span class="identifier">T</span></code> is <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>. Two optional - objects containing a value compare in the same as their contained values. + objects containing a value compare in the same way as their contained values. The uninitialized state of <code class="computeroutput"><span class="identifier">optional</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span></code> is treated as a distinct value, equal to itself, and unequal to any value of type <code class="computeroutput"><span class="identifier">T</span></code>: @@ -99,7 +99,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -107,7 +107,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="when_to_use_optional.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="optional_references.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="when_to_use_optional.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="io_operators.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/type_requirements.html b/libs/optional/doc/html/boost_optional/tutorial/type_requirements.html index 38a106d16..12cc30a59 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/type_requirements.html +++ b/libs/optional/doc/html/boost_optional/tutorial/type_requirements.html @@ -7,7 +7,7 @@ <link rel="home" href="../../index.html" title="Boost.Optional"> <link rel="up" href="../../optional/tutorial.html" title="Tutorial"> <link rel="prev" href="exception_safety_guarantees.html" title="Exception Safety Guarantees"> -<link rel="next" href="../../optional/reference.html" title="Reference"> +<link rel="next" href="performance_considerations.html" title="Performance considerations"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> @@ -20,7 +20,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="exception_safety_guarantees.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="exception_safety_guarantees.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="performance_considerations.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> @@ -95,7 +95,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> @@ -103,7 +103,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="exception_safety_guarantees.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../optional/reference.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="exception_safety_guarantees.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../optional/tutorial.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="performance_considerations.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html> diff --git a/libs/optional/doc/html/boost_optional/tutorial/when_to_use_optional.html b/libs/optional/doc/html/boost_optional/tutorial/when_to_use_optional.html index 58834461d..fd27d8026 100644 --- a/libs/optional/doc/html/boost_optional/tutorial/when_to_use_optional.html +++ b/libs/optional/doc/html/boost_optional/tutorial/when_to_use_optional.html @@ -128,7 +128,7 @@ </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> -<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014 Andrzej Krzemieński<p> +<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014, 2015 Andrzej Krzemieński<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) </p> |