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791 lines
30 KiB
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791 lines
30 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<!-- Copyright David Abrahams 2006. Distributed under the Boost -->
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<!-- Software License, Version 1.0. (See accompanying -->
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<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
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<html>
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<head>
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<meta name="generator" content=
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"HTML Tidy for Cygwin (vers 1st September 2004), see www.w3.org">
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<meta http-equiv="Content-Type" content="text/html; charset=iso-latin-1-dos">
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<link rel="stylesheet" type="text/css" href="../boost.css">
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<title>Boost.Python - <boost/python/class.hpp>,
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<boost/python/class_fwd.hpp></title>
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</head>
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<body link="#0000FF" vlink="#800080">
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<table border="0" cellpadding="7" cellspacing="0" width="100%" summary=
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"header">
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<tr>
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<td valign="top" width="300">
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<h3><a href="../../../../index.htm"><img height="86" width="277" alt=
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"C++ Boost" src="../../../../boost.png" border="0"></a></h3>
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</td>
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<td valign="top">
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<h1 align="center"><a href="../index.html">Boost.Python</a></h1>
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<h2 align="center">Headers <boost/python/class.hpp>,
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<boost/python/class_fwd.hpp></h2>
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</td>
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</tr>
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</table>
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<hr>
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<h2>Contents</h2>
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<dl class="page-index">
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<dt><a href="#introduction">Introduction</a></dt>
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<dt><a href="#classes">Classes</a></dt>
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<dd>
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<dl class="page-index">
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<dt><a href="#class_-spec">Class template
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<code>class_</code></a></dt>
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<dd>
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<dl class="page-index">
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<dt><a href="#class_-spec-synopsis">Class <code>class_</code>
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synopsis</a></dt>
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<dt><a href="#class_-spec-ctors">Class <code>class_</code>
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constructors</a></dt>
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<dt><a href="#class_-spec-modifiers">Class <code>class_</code>
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modifier functions</a></dt>
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</dl>
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</dd>
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<dt><a href="#bases-spec">Class template <code>bases</code></a></dt>
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<dd>
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<dl class="page-index">
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<dt><a href="#bases-spec-synopsis">Class template
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<code>bases</code> synopsis</a></dt>
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</dl>
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</dd>
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</dl>
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</dd>
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<dt><a href="#examples">Example(s)</a></dt>
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</dl>
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<hr>
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<h2><a name="introduction" id="introduction"></a>Introduction</h2>
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<p><code><boost/python/class.hpp></code> defines the interface
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through which users expose their C++ classes to Python. It declares the
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<code>class_</code> class template, which is parameterized on the class
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type being exposed. It also exposes the <code>init</code>,
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<code>optional</code> and <code>bases</code> utility class templates, which
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are used in conjunction with <code>class_</code>.</p>
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<p><code><boost/python/class_fwd.hpp></code> contains a forward
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declaration of the <code>class_</code> class template.</p>
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<h2><a name="classes" id="classes"></a>Classes</h2>
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<h3><a name="class_-spec" id="class_-spec"></a>Class template
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<code>class_<T, <font color="#007F00">Bases, HeldType,
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NonCopyable</font>></code></h3>
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<p>Creates a Python class associated with the C++ type passed as its first
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parameter. Although it has four template parameters, only the first one is
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required. The three optional arguments can actually be supplied
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<font color="#007F00"><b>in any order</b></font>; Boost.Python determines
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the role of the argument from its type.<br>
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<br></p>
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<table border="1" summary="class_ template parameters">
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<tr>
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<th>Template Parameter</th>
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<th>Requirements</th>
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<th>Semantics</th>
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<th>Default</th>
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</tr>
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<tr>
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<td><code>T</code></td>
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<td>A class type.</td>
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<td>The class being wrapped</td>
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</tr>
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<tr>
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<td><code><font color="#007F00">Bases</font></code></td>
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<td>A specialization of <a href=
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"#bases-spec"><code>bases<</code>...<code>></code></a> which
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specifies previously-exposed C++ base classes of <code>T</code><a href=
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"#footnote_1">[1]</a>.</td>
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<td>Registers <code>from_python</code> conversions from wrapped
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<code>T</code> instances to each of its exposed direct and indirect
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bases. For each polymorphic base <code>B</code>, registers conversions
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from indirectly-held wrapped <code>B</code> instances to
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<code>T</code>.</td>
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<td><code><a href="#bases-spec">bases<></a></code></td>
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</tr>
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<tr>
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<td><code><font color="#007F00">HeldType</font></code></td>
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<td>Must be <code>T</code>, a class derived from <code>T</code>, or a
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<a href="Dereferenceable.html">Dereferenceable</a> type for which
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<code><a href=
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"pointee.html#pointee-spec">pointee</a><HeldType>::type</code> is
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<code>T</code> or a class derived from <code>T</code>.</td>
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<td>Specifies the type that is actually embedded in a Python object
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wrapping a <code>T</code> instance when <code>T</code>'s constructor is
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called or when a <code>T</code> or <code>T*</code> is converted to
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Python without the use of <a href=
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"http://www.boost.org/libs/python/doc/v2/callbacks.html#argument_handling">
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<code>ptr</code></a>, <a href=
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"http://www.boost.org/libs/python/doc/v2/callbacks.html#argument_handling">
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<code>ref</code></a>, or <a href="CallPolicies.html">Call Policies</a>
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such as <code><a href=
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"return_internal_reference.html">return_internal_reference</a></code>.
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More details <a href="#HeldType">below</a>.</td>
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<td><code>T</code></td>
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</tr>
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<tr>
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<td><code><font color="#007F00">NonCopyable</font></code></td>
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<td>If supplied, must be <a href=
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"../../../utility/utility.htm#Class_noncopyable">boost::noncopyable</a>.</td>
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<td>Suppresses automatic registration of <code>to_python</code>
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conversions which copy <code>T</code> instances. Required when
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<code>T</code> has no publicly-accessible copy constructor.</td>
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<td>An unspecified type other than
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<code>boost::noncopyable</code>.</td>
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</tr>
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</table>
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<h4><a name="HeldType" id="HeldType">HeldType Semantics</a></h4>
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<ol>
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<li>If <code>HeldType</code> is derived from T, its exposed
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constructor(s) must accept an initial <code>PyObject*</code> argument
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which refers back to the Python object that contains the
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<code>HeldType</code> instance, as shown in <a href=
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"call_method.html#examples">this example</a>. This argument is not
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included in the <em><a href=
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"init.html#init-expressions">init-expression</a></em> passed to <a href=
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"#class_-spec-modifiers"><code>def(init_expr)</code></a>, below, nor is
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it passed explicitly by users when Python instances of <code>T</code> are
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created. This idiom allows C++ virtual functions which will be overridden
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in Python to access the Python object so the Python method can be
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invoked. Boost.Python automatically registers additional converters which
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allow wrapped instances of <code>T</code> to be passed to wrapped C++
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functions expecting <code>HeldType</code> arguments.</li>
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<li>Because Boost.Python will always allow wrapped instances of
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<code>T</code> to be passed in place of <code>HeldType</code> arguments,
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specifying a smart pointer for <code>HeldType</code> allows users to pass
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Python <code>T</code> instances where a smart pointer-to-<code>T</code>
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is expected. Smart pointers such as <code>std::auto_ptr<></code> or
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<code><a href=
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"../../../smart_ptr/shared_ptr.htm">boost::shared_ptr<></a></code>
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which contain a nested type <code>element_type</code> designating the
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referent type are automatically supported; additional smart pointer types
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can be supported by specializing <a href=
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"pointee.html#pointee-spec">pointee<HeldType></a>.</li>
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<li>As in case 1 above, when <code>HeldType</code> is a smart pointer to
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a class derived from <code>T</code>, the initial <code>PyObject*</code>
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argument must be supplied by all of <code>HeldType</code>'s exposed
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constructors.</li>
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<li>Except in cases 1 and 3, users may optionally specify that T itself
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gets initialized with a similar initial <code>PyObject*</code> argument
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by specializing <a href=
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"has_back_reference.html#has_back_reference-spec">has_back_reference<T></a>.</li>
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</ol>
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<h4><a name="class_-spec-synopsis" id="class_-spec-synopsis"></a>Class
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template <code>class_</code> synopsis</h4>
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<pre>
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namespace boost { namespace python
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{
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template <class T
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<font color="#007F00"> , class Bases = bases<>
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, class HeldType = T
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, class NonCopyable = <i>unspecified</i>
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>
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</font> class class_ : public <a href="object.html#object-spec">object</a>
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{
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// Constructors with default __init__
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class_(char const* name);
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class_(char const* name, char const* docstring);
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// Constructors, specifying non-default __init__
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template <class Init>
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class_(char const* name, Init);
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template <class Init>
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class_(char const* name, char const* docstring, Init);
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// Exposing additional __init__ functions
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template <class Init>
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class_& def(Init);
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// defining methods
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template <class F>
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class_& def(char const* name, F f);
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template <class Fn, class A1>
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class_& def(char const* name, Fn fn, A1 const&);
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template <class Fn, class A1, class A2>
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class_& def(char const* name, Fn fn, A1 const&, A2 const&);
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template <class Fn, class A1, class A2, class A3>
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class_& def(char const* name, Fn fn, A1 const&, A2 const&, A3 const&);
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// declaring method as static
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class_& staticmethod(char const* name);
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// exposing operators
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template <<i>unspecified</i>>
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class_& def(<a href=
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"operators.html#operator_-spec">detail::operator_</a><unspecified>);
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// Raw attribute modification
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template <class U>
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class_& setattr(char const* name, U const&);
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// exposing data members
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template <class D>
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class_& def_readonly(char const* name, D T::*pm);
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template <class D>
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class_& def_readwrite(char const* name, D T::*pm);
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// exposing static data members
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template <class D>
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class_& def_readonly(char const* name, D const& d);
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template <class D>
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class_& def_readwrite(char const* name, D& d);
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// property creation
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template <class Get>
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void add_property(char const* name, Get const& fget, char const* doc=0);
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template <class Get, class Set>
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void add_property(
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char const* name, Get const& fget, Set const& fset, char const* doc=0);
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template <class Get>
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void add_static_property(char const* name, Get const& fget);
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template <class Get, class Set>
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void add_static_property(char const* name, Get const& fget, Set const& fset);
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// pickle support
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template <typename PickleSuite>
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self& def_pickle(PickleSuite const&);
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self& enable_pickling();
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};
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}}
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</pre>
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<h4><a name="class_-spec-ctors" id="class_-spec-ctors"></a>Class template
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<code>class_</code> constructors</h4>
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<pre>
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class_(char const* name);
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class_(char const* name, char const* docstring);
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template <class Init>
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class_(char const* name, Init init_spec);
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template <class Init>
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class_(char const* name, char const* docstring, Init init_spec);
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</pre>
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<dl class="function-semantics">
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<dt><b>Requires:</b> <code>name</code> is an <a href=
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"definitions.html#ntbs">ntbs</a> which conforms to Python's <a href=
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"http://www.python.org/doc/current/ref/identifiers.html">identifier
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naming rules</a>. If <code>docstring</code> is supplied, it must be an
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<a href="definitions.html#ntbs">ntbs</a>. If <code>init_spec</code> is
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supplied, it must be either the special enumeration constant
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<code>no_init</code> or an <a href=
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"init.html#init-expressions">init-expression</a> compatible with
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<code>T</code>.</dt>
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<dt><b>Effects:</b> Constructs a <code>class_</code> object holding a
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Boost.Python extension class named <code>name</code>. The
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<code>name</code>d attribute of the <a href=
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"scope.html#introduction">current scope</a> is bound to the new extension
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class.</dt>
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<dd>
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<ul>
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<li>If supplied, the value of <code>docstring</code> is bound to the
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<code>__doc__</code> attribute of the extension class.</li>
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<li>If <code>init_spec</code> is <code>no_init</code>, a special
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<code>__init__</code> function is generated which always raises a
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Python exception. Otherwise, <code>this->def(init_spec)</code> is
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called.</li>
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<li>If <code>init_spec</code> is not supplied,
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<code>this->def(init<>())</code> is called.</li>
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</ul>
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</dd>
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<dt><b>Rationale:</b>Allowing the user to specify constructor arguments
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in the <code>class_<></code> constructor helps her to avoid the
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common run-time errors which result from invoking wrapped member
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functions without having exposed an <code>__init__</code> function which
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creates the requisite <code>T</code> instance. Types which are not
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default-constructible will cause a compile-time error unless
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<code>Init</code> is supplied. The user must always supply
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<code>name</code> as there is currently no portable method to derive the
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text of the class name from its type.</dt>
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</dl>
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<h4><a name="class_-spec-modifiers" id="class_-spec-modifiers"></a>Class
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template <code>class_</code> modifier functions</h4>
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<pre>
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template <class Init>
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class_& def(Init init_expr);
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</pre>
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<dl class="function-semantics">
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<dt><b>Requires:</b> <code>init_expr</code> is the result of an <a href=
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"init.html#init-expressions">init-expression</a> compatible with
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<code>T</code>.</dt>
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<dt><b>Effects:</b> For each <a href="init.html#init-expressions">valid
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prefix</a> <em>P</em> of <code>Init</code>, adds an
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<code>__init__(</code>...<code>)</code> function overload to the
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extension class accepting <em>P</em> as arguments. Each overload
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generated constructs an object of <code>HeldType</code> according to the
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semantics described <a href="#HeldType">above</a>, using a copy of
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<code>init_expr</code>'s <a href="CallPolicies.html">call policies</a>.
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If the longest <a href="init.html#init-expressions">valid prefix</a> of
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<code>Init</code> contains <em>N</em> types and <code>init_expr</code>
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holds <em>M</em> keywords, an initial sequence of the keywords are used
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for all but the first <em>N</em> - <em>M</em> arguments of each
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overload.</dt>
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<dt><b>Returns:</b> <code>*this</code></dt>
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<dt><b>Rationale:</b> Allows users to easily expose a class' constructor
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to Python.</dt>
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</dl><br>
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<pre>
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template <class F>
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class_& def(char const* name, Fn fn);
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template <class Fn, class A1>
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class_& def(char const* name, Fn fn, A1 const& a1);
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template <class Fn, class A1, class A2>
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class_& def(char const* name, Fn fn, A1 const& a1, A2 const& a2);
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template <class Fn, class A1, class A2, class A3>
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class_& def(char const* name, Fn fn, A1 const& a1, A2 const& a2, A3 const& a3);
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</pre>
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|
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<dl class="function-semantics">
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<dt><b>Requires:</b> <code>name</code> is an <a href=
|
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"definitions.html#ntbs">ntbs</a> which conforms to Python's <a href=
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"http://www.python.org/doc/current/ref/identifiers.html">identifier
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naming rules</a>.</dt>
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|
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<dd>
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<ul>
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<li>If <code>a1</code> is the result of an <a href=
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"overloads.html#overload-dispatch-expression"><em>overload-dispatch-expression</em></a>,
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only the second form is allowed and fn must be a pointer to function
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or pointer to member function whose <a href="definitions.html#arity">
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arity</a> is the same as A1's <a href=
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"overloads.html#overload-dispatch-expression"><em>maximum
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arity</em></a>.
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<dl>
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<dt><b>Effects:</b> For each prefix <em>P</em> of
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<code>Fn</code>'s sequence of argument types, beginning with the
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one whose length is <code>A1</code>'s <a href=
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"overloads.html#overload-dispatch-expression"><em>minimum
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arity</em></a>, adds a
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<code><em>name</em>(</code>...<code>)</code> method overload to
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the extension class. Each overload generated invokes
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<code>a1</code>'s call-expression with <em>P</em>, using a copy
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of <code>a1</code>'s <a href="CallPolicies.html">call
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policies</a>. If the longest valid prefix of <code>A1</code>
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contains <em>N</em> types and <code>a1</code> holds <em>M</em>
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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>
|