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diff --git a/libs/python/doc/v2/class.html b/libs/python/doc/v2/class.html new file mode 100644 index 000000000..edfc60970 --- /dev/null +++ b/libs/python/doc/v2/class.html @@ -0,0 +1,790 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> + +<!-- Copyright David Abrahams 2006. Distributed under the Boost --> +<!-- Software License, Version 1.0. (See accompanying --> +<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) --> +<html> +<head> + <meta name="generator" content= + "HTML Tidy for Cygwin (vers 1st September 2004), see www.w3.org"> + <meta http-equiv="Content-Type" content="text/html; charset=iso-latin-1-dos"> + <link rel="stylesheet" type="text/css" href="../boost.css"> + + <title>Boost.Python - <boost/python/class.hpp>, + <boost/python/class_fwd.hpp></title> +</head> + +<body link="#0000FF" vlink="#800080"> + <table border="0" cellpadding="7" cellspacing="0" width="100%" summary= + "header"> + <tr> + <td valign="top" width="300"> + <h3><a href="../../../../index.htm"><img height="86" width="277" alt= + "C++ Boost" src="../../../../boost.png" border="0"></a></h3> + </td> + + <td valign="top"> + <h1 align="center"><a href="../index.html">Boost.Python</a></h1> + + <h2 align="center">Headers <boost/python/class.hpp>, + <boost/python/class_fwd.hpp></h2> + </td> + </tr> + </table> + <hr> + + <h2>Contents</h2> + + <dl class="page-index"> + <dt><a href="#introduction">Introduction</a></dt> + + <dt><a href="#classes">Classes</a></dt> + + <dd> + <dl class="page-index"> + <dt><a href="#class_-spec">Class template + <code>class_</code></a></dt> + + <dd> + <dl class="page-index"> + <dt><a href="#class_-spec-synopsis">Class <code>class_</code> + synopsis</a></dt> + + <dt><a href="#class_-spec-ctors">Class <code>class_</code> + constructors</a></dt> + + <dt><a href="#class_-spec-modifiers">Class <code>class_</code> + modifier functions</a></dt> + </dl> + </dd> + + <dt><a href="#bases-spec">Class template <code>bases</code></a></dt> + + <dd> + <dl class="page-index"> + <dt><a href="#bases-spec-synopsis">Class template + <code>bases</code> synopsis</a></dt> + </dl> + </dd> + </dl> + </dd> + + <dt><a href="#examples">Example(s)</a></dt> + </dl> + <hr> + + <h2><a name="introduction" id="introduction"></a>Introduction</h2> + + <p><code><boost/python/class.hpp></code> defines the interface + through which users expose their C++ classes to Python. It declares the + <code>class_</code> class template, which is parameterized on the class + type being exposed. It also exposes the <code>init</code>, + <code>optional</code> and <code>bases</code> utility class templates, which + are used in conjunction with <code>class_</code>.</p> + + <p><code><boost/python/class_fwd.hpp></code> contains a forward + declaration of the <code>class_</code> class template.</p> + + <h2><a name="classes" id="classes"></a>Classes</h2> + + <h3><a name="class_-spec" id="class_-spec"></a>Class template + <code>class_<T, <font color="#007F00">Bases, HeldType, + NonCopyable</font>></code></h3> + + <p>Creates a Python class associated with the C++ type passed as its first + parameter. Although it has four template parameters, only the first one is + required. The three optional arguments can actually be supplied + <font color="#007F00"><b>in any order</b></font>; Boost.Python determines + the role of the argument from its type.<br> + <br></p> + + <table border="1" summary="class_ template parameters"> + <tr> + <th>Template Parameter</th> + + <th>Requirements</th> + + <th>Semantics</th> + + <th>Default</th> + </tr> + + <tr> + <td><code>T</code></td> + + <td>A class type.</td> + + <td>The class being wrapped</td> + </tr> + + <tr> + <td><code><font color="#007F00">Bases</font></code></td> + + <td>A specialization of <a href= + "#bases-spec"><code>bases<</code>...<code>></code></a> which + specifies previously-exposed C++ base classes of <code>T</code><a href= + "#footnote_1">[1]</a>.</td> + + <td>Registers <code>from_python</code> conversions from wrapped + <code>T</code> instances to each of its exposed direct and indirect + bases. For each polymorphic base <code>B</code>, registers conversions + from indirectly-held wrapped <code>B</code> instances to + <code>T</code>.</td> + + <td><code><a href="#bases-spec">bases<></a></code></td> + </tr> + + <tr> + <td><code><font color="#007F00">HeldType</font></code></td> + + <td>Must be <code>T</code>, a class derived from <code>T</code>, or a + <a href="Dereferenceable.html">Dereferenceable</a> type for which + <code><a href= + "pointee.html#pointee-spec">pointee</a><HeldType>::type</code> is + <code>T</code> or a class derived from <code>T</code>.</td> + + <td>Specifies the type that is actually embedded in a Python object + wrapping a <code>T</code> instance when <code>T</code>'s constructor is + called or when a <code>T</code> or <code>T*</code> is converted to + Python without the use of <a href= + "http://www.boost.org/libs/python/doc/v2/callbacks.html#argument_handling"> + <code>ptr</code></a>, <a href= + "http://www.boost.org/libs/python/doc/v2/callbacks.html#argument_handling"> + <code>ref</code></a>, or <a href="CallPolicies.html">Call Policies</a> + such as <code><a href= + "return_internal_reference.html">return_internal_reference</a></code>. + More details <a href="#HeldType">below</a>.</td> + + <td><code>T</code></td> + </tr> + + <tr> + <td><code><font color="#007F00">NonCopyable</font></code></td> + + <td>If supplied, must be <a href= + "../../../utility/utility.htm#Class_noncopyable">boost::noncopyable</a>.</td> + + <td>Suppresses automatic registration of <code>to_python</code> + conversions which copy <code>T</code> instances. Required when + <code>T</code> has no publicly-accessible copy constructor.</td> + + <td>An unspecified type other than + <code>boost::noncopyable</code>.</td> + </tr> + </table> + + <h4><a name="HeldType" id="HeldType">HeldType Semantics</a></h4> + + <ol> + <li>If <code>HeldType</code> is derived from T, its exposed + constructor(s) must accept an initial <code>PyObject*</code> argument + which refers back to the Python object that contains the + <code>HeldType</code> instance, as shown in <a href= + "call_method.html#examples">this example</a>. This argument is not + included in the <em><a href= + "init.html#init-expressions">init-expression</a></em> passed to <a href= + "#class_-spec-modifiers"><code>def(init_expr)</code></a>, below, nor is + it passed explicitly by users when Python instances of <code>T</code> are + created. This idiom allows C++ virtual functions which will be overridden + in Python to access the Python object so the Python method can be + invoked. Boost.Python automatically registers additional converters which + allow wrapped instances of <code>T</code> to be passed to wrapped C++ + functions expecting <code>HeldType</code> arguments.</li> + + <li>Because Boost.Python will always allow wrapped instances of + <code>T</code> to be passed in place of <code>HeldType</code> arguments, + specifying a smart pointer for <code>HeldType</code> allows users to pass + Python <code>T</code> instances where a smart pointer-to-<code>T</code> + is expected. Smart pointers such as <code>std::auto_ptr<></code> or + <code><a href= + "../../../smart_ptr/shared_ptr.htm">boost::shared_ptr<></a></code> + which contain a nested type <code>element_type</code> designating the + referent type are automatically supported; additional smart pointer types + can be supported by specializing <a href= + "pointee.html#pointee-spec">pointee<HeldType></a>.</li> + + <li>As in case 1 above, when <code>HeldType</code> is a smart pointer to + a class derived from <code>T</code>, the initial <code>PyObject*</code> + argument must be supplied by all of <code>HeldType</code>'s exposed + constructors.</li> + + <li>Except in cases 1 and 3, users may optionally specify that T itself + gets initialized with a similar initial <code>PyObject*</code> argument + by specializing <a href= + "has_back_reference.html#has_back_reference-spec">has_back_reference<T></a>.</li> + </ol> + + <h4><a name="class_-spec-synopsis" id="class_-spec-synopsis"></a>Class + template <code>class_</code> synopsis</h4> + <pre> +namespace boost { namespace python +{ + template <class T + <font color="#007F00"> , class Bases = bases<> + , class HeldType = T + , class NonCopyable = <i>unspecified</i> + > +</font> class class_ : public <a href="object.html#object-spec">object</a> + { + // Constructors with default __init__ + class_(char const* name); + class_(char const* name, char const* docstring); + + // Constructors, specifying non-default __init__ + template <class Init> + class_(char const* name, Init); + template <class Init> + class_(char const* name, char const* docstring, Init); + + // Exposing additional __init__ functions + template <class Init> + class_& def(Init); + + // defining methods + template <class F> + class_& def(char const* name, F f); + template <class Fn, class A1> + class_& def(char const* name, Fn fn, A1 const&); + template <class Fn, class A1, class A2> + class_& def(char const* name, Fn fn, A1 const&, A2 const&); + template <class Fn, class A1, class A2, class A3> + class_& def(char const* name, Fn fn, A1 const&, A2 const&, A3 const&); + + // declaring method as static + class_& staticmethod(char const* name); + + // exposing operators + template <<i>unspecified</i>> + class_& def(<a href= +"operators.html#operator_-spec">detail::operator_</a><unspecified>); + + // Raw attribute modification + template <class U> + class_& setattr(char const* name, U const&); + + // exposing data members + template <class D> + class_& def_readonly(char const* name, D T::*pm); + + template <class D> + class_& def_readwrite(char const* name, D T::*pm); + + // exposing static data members + template <class D> + class_& def_readonly(char const* name, D const& d); + template <class D> + class_& def_readwrite(char const* name, D& d); + + // property creation + template <class Get> + void add_property(char const* name, Get const& fget, char const* doc=0); + template <class Get, class Set> + void add_property( + char const* name, Get const& fget, Set const& fset, char const* doc=0); + + template <class Get> + void add_static_property(char const* name, Get const& fget); + template <class Get, class Set> + void add_static_property(char const* name, Get const& fget, Set const& fset); + + // pickle support + template <typename PickleSuite> + self& def_pickle(PickleSuite const&); + self& enable_pickling(); + }; +}} +</pre> + + <h4><a name="class_-spec-ctors" id="class_-spec-ctors"></a>Class template + <code>class_</code> constructors</h4> + <pre> +class_(char const* name); +class_(char const* name, char const* docstring); +template <class Init> +class_(char const* name, Init init_spec); +template <class Init> +class_(char const* name, char const* docstring, Init init_spec); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>. If <code>docstring</code> is supplied, it must be an + <a href="definitions.html#ntbs">ntbs</a>. If <code>init_spec</code> is + supplied, it must be either the special enumeration constant + <code>no_init</code> or an <a href= + "init.html#init-expressions">init-expression</a> compatible with + <code>T</code>.</dt> + + <dt><b>Effects:</b> Constructs a <code>class_</code> object holding a + Boost.Python extension class named <code>name</code>. The + <code>name</code>d attribute of the <a href= + "scope.html#introduction">current scope</a> is bound to the new extension + class.</dt> + + <dd> + <ul> + <li>If supplied, the value of <code>docstring</code> is bound to the + <code>__doc__</code> attribute of the extension class.</li> + + <li>If <code>init_spec</code> is <code>no_init</code>, a special + <code>__init__</code> function is generated which always raises a + Python exception. Otherwise, <code>this->def(init_spec)</code> is + called.</li> + + <li>If <code>init_spec</code> is not supplied, + <code>this->def(init<>())</code> is called.</li> + </ul> + </dd> + + <dt><b>Rationale:</b>Allowing the user to specify constructor arguments + in the <code>class_<></code> constructor helps her to avoid the + common run-time errors which result from invoking wrapped member + functions without having exposed an <code>__init__</code> function which + creates the requisite <code>T</code> instance. Types which are not + default-constructible will cause a compile-time error unless + <code>Init</code> is supplied. The user must always supply + <code>name</code> as there is currently no portable method to derive the + text of the class name from its type.</dt> + </dl> + + <h4><a name="class_-spec-modifiers" id="class_-spec-modifiers"></a>Class + template <code>class_</code> modifier functions</h4> + <pre> +template <class Init> +class_& def(Init init_expr); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>init_expr</code> is the result of an <a href= + "init.html#init-expressions">init-expression</a> compatible with + <code>T</code>.</dt> + + <dt><b>Effects:</b> For each <a href="init.html#init-expressions">valid + prefix</a> <em>P</em> of <code>Init</code>, adds an + <code>__init__(</code>...<code>)</code> function overload to the + extension class accepting <em>P</em> as arguments. Each overload + generated constructs an object of <code>HeldType</code> according to the + semantics described <a href="#HeldType">above</a>, using a copy of + <code>init_expr</code>'s <a href="CallPolicies.html">call policies</a>. + If the longest <a href="init.html#init-expressions">valid prefix</a> of + <code>Init</code> contains <em>N</em> types and <code>init_expr</code> + holds <em>M</em> keywords, an initial sequence of the keywords are used + for all but the first <em>N</em> - <em>M</em> arguments of each + overload.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Allows users to easily expose a class' constructor + to Python.</dt> + </dl><br> + <pre> +template <class F> +class_& def(char const* name, Fn fn); +template <class Fn, class A1> +class_& def(char const* name, Fn fn, A1 const& a1); +template <class Fn, class A1, class A2> +class_& def(char const* name, Fn fn, A1 const& a1, A2 const& a2); +template <class Fn, class A1, class A2, class A3> +class_& def(char const* name, Fn fn, A1 const& a1, A2 const& a2, A3 const& a3); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>.</dt> + + <dd> + <ul> + <li>If <code>a1</code> is the result of an <a href= + "overloads.html#overload-dispatch-expression"><em>overload-dispatch-expression</em></a>, + only the second form is allowed and fn must be a pointer to function + or pointer to member function whose <a href="definitions.html#arity"> + arity</a> is the same as A1's <a href= + "overloads.html#overload-dispatch-expression"><em>maximum + arity</em></a>. + + <dl> + <dt><b>Effects:</b> For each prefix <em>P</em> of + <code>Fn</code>'s sequence of argument types, beginning with the + one whose length is <code>A1</code>'s <a href= + "overloads.html#overload-dispatch-expression"><em>minimum + arity</em></a>, adds a + <code><em>name</em>(</code>...<code>)</code> method overload to + the extension class. Each overload generated invokes + <code>a1</code>'s call-expression with <em>P</em>, using a copy + of <code>a1</code>'s <a href="CallPolicies.html">call + policies</a>. If the longest valid prefix of <code>A1</code> + contains <em>N</em> types and <code>a1</code> holds <em>M</em> + keywords, an initial sequence of the keywords are used for all + but the first <em>N</em> - <em>M</em> arguments of each + overload.<br></dt> + </dl> + </li> + + <li>Otherwise, a single method overload is built around fn, which + must not be null: + + <ul> + <li>If fn is a function pointer, its first argument must be of + the form <code>U</code>, <code>U <em>cv</em>&</code>, <code>U + <em>cv</em>*</code>, or <code>U <em>cv</em>* const&</code>, + where <code>T*</code> is convertible to <code>U*</code>, and + <code>a1</code>-<code>a3</code>, if supplied, may be selected in + any order from the table below.</li> + + <li>Otherwise, if fn is a member function pointer, its target + must be <code>T</code> or one of its public base classes, and + <code>a1</code>-<code>a3</code>, if supplied, may be selected in + any order from the table below.</li> + + <li>Otherwise, <code>Fn</code> must be [derived from] + <code><a href="object.html#object-spec">object</a></code>, and + <code>a1-a2</code>, if supplied, may be selcted in any order from + the first two rows of the table below. To be useful, + <code>fn</code> should be <a href= + "http://www.python.org/doc/current/lib/built-in-funcs.html#l2h-6"> + callable</a>.</li> + </ul> + + <table border="1" summary="def() optional arguments"> + <tr> + <th>Memnonic Name</th> + + <th>Requirements/Type properties</th> + + <th>Effects</th> + </tr> + + <tr> + <td>docstring</td> + + <td>Any <a href="definitions.html#ntbs">ntbs</a>.</td> + + <td>Value will be bound to the <code>__doc__</code> attribute + of the resulting method overload. If an earlier overload + supplied a docstring, two newline characters and the new + docstring are appended to it.</td> + </tr> + + <tr> + <td>policies</td> + + <td>A model of <a href= + "CallPolicies.html">CallPolicies</a></td> + + <td>A copy will be used as the call policies of the resulting + method overload.</td> + </tr> + + <tr> + <td>keywords</td> + + <td>The result of a <a href= + "args.html#keyword-expression"><em>keyword-expression</em></a> + specifying no more arguments than the <a href= + "definitions.html#arity">arity</a> of <code>fn</code>.</td> + + <td>A copy will be used as the call policies of the resulting + method overload.</td> + </tr> + </table> + </li> + </ul> + </dd> + + <dt><b>Returns:</b> <code>*this</code></dt> + </dl> + <pre> +class_& staticmethod(char const* name); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>, and corresponds to a method whose overloads have all + been defined.</dt> + + <dt><b>Effects:</b> Replaces the existing named attribute <i>x</i> with + the result of invoking <code>staticmethod(</code><i>x</i><code>)</code> + in Python. Specifies that the corresponding method is static and + therefore no object instance will be passed to it. This is equivalent to + the Python statement:</dt> + + <dd> + <pre> +setattr(self, name, staticmethod(getattr(self, name))) +</pre> + </dd> + + <dt><b>Note:</b> Attempting to invoke <code>def(name,...)</code> after + invoking <code>staticmethod(name)</code> will <a href= + "definitions.html#raise">raise</a> a RuntimeError.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + </dl><br> + <pre> +template <<i>unspecified</i>> +class_& def(<a href= +"operators.html#operator_-spec">detail::operator_</a><unspecified>); +</pre> + + <dl class="function-semantics"> + <dt><b>Effects:</b> Adds a Python <a href= + "http://www.python.org/doc/ref/specialnames.html">special method</a> as + described <a href="operators.html">here</a>.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + </dl> + <pre> +template <class U> +class_& setattr(char const* name, U const& u); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>.</dt> + + <dt><b>Effects:</b> Converts u to Python and adds it to the attribute + dictionary of the extension class:</dt> + + <dd> + <blockquote> + <code><a href= + "http://www.python.org/doc/current/api/object.html#l2h-166">PyObject_SetAttrString</a>(this->ptr(), + name, <a href= + "object.html#object-spec-ctors">object</a>(u).ptr());</code> + </blockquote> + </dd> + + <dt><b>Returns:</b> <code>*this</code></dt> + </dl><br> + <pre> +template <class Get> +void add_property(char const* name, Get const& fget, char const* doc=0); +template <class Get, class Set> +void add_property( + char const* name, Get const& fget, Set const& fset, char const* doc=0); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conform to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>.</dt> + + <dt><b>Effects:</b> Creates a new Python <a href= + "http://www.python.org/2.2.2/descrintro.html#property"><code>property</code></a> + class instance, passing <code><a href= + "object.html#object-spec-ctors">object</a>(fget)</code> (and + <code><a href="object.html#object-spec-ctors">object</a>(fset)</code> in + the second form) with an (optional) docstring <code>doc</code> to its + constructor, then adds that property to the Python class object under + construction with the given attribute <code>name</code>.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Allows users to easily expose functions that can be + invoked from Python with attribute access syntax.</dt> + </dl><br> + <pre> +template <class Get> +void add_static_property(char const* name, Get const& fget); +template <class Get, class Set> +void add_static_property(char const* name, Get const& fget, Set const& fset); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>.</dt> + + <dt><b>Effects:</b> Creates a Boost.Python.StaticProperty object, passing + <code><a href="object.html#object-spec-ctors">object</a>(fget)</code> + (and <code><a href= + "object.html#object-spec-ctors">object</a>(fset)</code> in the second + form) to its constructor, then adds that property to the Python class + under construction with the given attribute <code>name</code>. + StaticProperty is a special subclass of Python's <a href= + "http://www.python.org/2.2.2/descrintro.html#property"><code>property</code></a> + class which can be called without an initial <code>self</code> + argument.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Allows users to easily expose functions that can be + invoked from Python with static attribute access syntax.</dt> + </dl><br> + <pre> +template <class D> +class_& def_readonly(char const* name, D T::*pm, char const* doc=0); +template <class D> +class_& def_readonly(char const* name, D const& d); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> <code>name</code> is an <a href= + "definitions.html#ntbs">ntbs</a> which conforms to Python's <a href= + "http://www.python.org/doc/current/ref/identifiers.html">identifier + naming rules</a>. <code>doc</code> is also an ntbs.</dt> + + <dt><b>Effects:</b></dt> + + <dd> + <pre> +this->add_property(name, <a href= +"data_members.html#make_getter-spec">make_getter</a>(pm), doc); +</pre>and + <pre> +this->add_static_property(name, <a href= +"data_members.html#make_getter-spec">make_getter</a>(d)); +</pre>respectively.<br> + <br> + </dd> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Allows users to easily expose a class' data member + or free variable such that it can be inspected from Python with a natural + syntax.</dt> + </dl> + <pre> +template <class D> +class_& def_readwrite(char const* name, D T::*pm, char const* doc=0); +template <class D> +class_& def_readwrite(char const* name, D& d); +</pre> + + <dl class="function-semantics"> + <dt><b>Effects:</b></dt> + + <dd> + <pre> +this->add_property(name, <a href= +"data_members.html#make_getter-spec">make_getter</a>(pm), <a href= +"data_members.html#make_setter-spec">make_setter</a>(pm), doc); +</pre>and + <pre> +this->add_static_property(name, <a href= +"data_members.html#make_getter-spec">make_getter</a>(d), <a href= +"data_members.html#make_setter-spec">make_setter</a>(d)); +</pre>respectively.<br> + <br> + </dd> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Allows users to easily expose a class' data or free + variable member such that it can be inspected and set from Python with a + natural syntax.</dt> + </dl> + <pre> +template <typename PickleSuite> +class_& def_pickle(PickleSuite const&); +</pre> + + <dl class="function-semantics"> + <dt><b>Requires:</b> PickleSuite must be publically derived from <a href= + "pickle.html"><code>pickle_suite</code></a>.</dt> + + <dt><b>Effects:</b> Defines a legal combination of the special attributes + and methods: <code>__getinitargs__</code>, <code>__getstate__</code>, + <code>__setstate__</code>, <code>__getstate_manages_dict__</code>, + <code>__safe_for_unpickling__</code>, <code>__reduce__</code></dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Provides an <a href="pickle.html">easy to use + high-level interface</a> for establishing complete pickle support for the + wrapped class. The user is protected by compile-time consistency + checks.</dt> + </dl><br> + <pre> +class_& enable_pickling(); +</pre> + + <dl class="function-semantics"> + <dt><b>Effects:</b> Defines the <code>__reduce__</code> method and the + <code>__safe_for_unpickling__</code> attribute.</dt> + + <dt><b>Returns:</b> <code>*this</code></dt> + + <dt><b>Rationale:</b> Light-weight alternative to + <code>def_pickle()</code>. Enables implementation of <a href= + "pickle.html">pickle support</a> from Python.</dt> + </dl><br> + + <h3><a name="bases-spec" id="bases-spec"></a>Class template + <code>bases<T1, T2,</code>...<code>TN></code></h3> + + <p>An <a href="../../../mpl/doc/refmanual/forward-sequence.html">MPL + sequence</a> which can be used in + <code>class_<</code>...<code>></code> instantiations indicate a list + of base classes.</p> + + <h4><a name="bases-spec-synopsis" id="bases-spec-synopsis"></a>Class + template <code>bases</code> synopsis</h4> + <pre> +namespace boost { namespace python +{ + template <T1 = <i>unspecified</i>,...T<i>n</i> = <i>unspecified</i>> + struct bases + {}; +}} +</pre> + + <h2><a name="examples" id="examples"></a>Example(s)</h2> + + <p>Given a C++ class declaration:</p> + <pre> +class Foo : public Bar, public Baz +{ + public: + Foo(int x, char const* y); + Foo(double); + + std::string const& name() { return m_name; } + void name(char const*); + + double value; // public data + private: + ... +}; +</pre>A corresponding Boost.Python extension class can be created with: + <pre> +using namespace boost::python; + +class_<Foo,bases<Bar,Baz> >("Foo", + "This is Foo's docstring." + "It describes our Foo extension class", + + init<int,char const*>(args("x","y"), "__init__ docstring") + ) + .def(init<double>()) + .def("get_name", &Foo::get_name, return_internal_reference<>()) + .def("set_name", &Foo::set_name) + .def_readwrite("value", &Foo::value) + ; +</pre> + <hr> + <a name="footnote_1" id="footnote_1">[1]</a> By "previously-exposed" we + mean that the for each <code>B</code> in <code>bases</code>, an instance of + <code>class_<B<font color="#007F00">, ...</font>></code> must have + already been constructed. + <pre> +class_<Base>("Base"); +class_<Derived, bases<Base> >("Derived"); +</pre>Revised +<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan --> + 1 November, 2005 <!--webbot bot="Timestamp" endspan i-checksum="39359" --> + + <p><i>© Copyright <a href="http://www.boost.org/people/dave_abrahams.htm">Dave + Abrahams</a> 2002.</i></p> +</body> +</html> |