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<html>
<head>
<title>BOOST_PP_IDENTITY</title>
<link rel="stylesheet" type="text/css" href="../styles.css">
</head>
<body>
<div style="margin-left: 0px;">
The <b>BOOST_PP_IDENTITY</b> macro expands to its argument when invoked.
</div>
<h4>Usage</h4>
<div class="code">
<b>BOOST_PP_IDENTITY</b>(<i>item</i>)()
</div>
<h4>Arguments</h4>
<dl>
<dt>item</dt>
<dd>
The result of the expansion.
</dd>
</dl>
<h4>Remarks</h4>
<div>
This macro is designed to be used with <b>BOOST_PP_IF</b> and <b>BOOST_PP_IIF</b> when only one of the clauses needs to be invoked.
</div>
<h4>See Also</h4>
<ul>
<li><a href="if.html">BOOST_PP_IF</a></li>
<li><a href="iif.html">BOOST_PP_IIF</a></li>
</ul>
<h4>Requirements</h4>
<div>
<b>Header:</b> <a href="../headers/facilities/identity.html"><boost/preprocessor/facilities/identity.hpp></a>
</div>
<h4>Sample Code</h4>
<div><pre>
#include <<a href="../headers/control/if.html">boost/preprocessor/control/if.hpp</a>>
#include <<a href="../headers/facilities/empty.html">boost/preprocessor/facilities/empty.hpp</a>>
#include <<a href="../headers/facilities/identity.html">boost/preprocessor/facilities/identity.hpp</a>>
#define MACRO(n) <a href="if.html">BOOST_PP_IF</a>(n, <a href="identity.html">BOOST_PP_IDENTITY</a>(x), <a href="empty.html">BOOST_PP_EMPTY</a>)()
MACRO(0) // expands to nothing
MACRO(1) // expands to x
</pre></div>
<hr size="1">
<div style="margin-left: 0px;">
<i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
</br><i>© Copyright Paul Mensonides 2002</i>
</div>
<div style="margin-left: 0px;">
<p><small>Distributed under the Boost Software License, Version 1.0. (See
accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
copy at <a href=
"http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
</div>
</body>
</html>
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