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<h1 align="center"><a href="../index.html">Boost.Python</a></h1>
<h2 align="center">Header <call.hpp></h2>
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<h2>Contents</h2>
<dl class="page-index">
<dt><a href="#introduction">Introduction</a></dt>
<dt><a href="#functions">Functions</a></dt>
<dl class="page-index">
<dt><a href="#call-spec">call</a></dt>
</dl>
<dt><a href="#examples">Example(s)</a></dt>
</dl>
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<h2><a name="introduction"></a>Introduction</h2>
<p>
<code><boost/python/call.hpp></code> defines the <a
href="#call-spec"><code>call</code></a> family of overloaded function
templates, used to invoke Python callable objects from C++.
<h2><a name="functions"></a>Functions</h2>
<pre>
<a name="call-spec">template <class R, class A1, class A2, ... class A<i>n</i>></a>
R call(PyObject* callable, A1 const&, A2 const&, ... A<i>n</i> const&)
</pre>
<dl class="function-semantics">
<dt><b>Requires:</b> <code>R</code> is a pointer type, reference
type, or a complete type with an accessible copy constructor</dt>
<dt><b>Effects:</b> Invokes <code>callable(a1, a2, ...a<i>n</i>)</code> in
Python, where <code>a1</code>...<code>a<i>n</i></code> are the arguments to
<code>call()</code>, converted to Python objects.
<dt><b>Returns:</b> The result of the Python call, converted to the C++ type <code>R</code>.</dt>
</dt>
<dt><b>Rationale:</b> For a complete semantic description and
rationale, see <a href="callbacks.html">this page</a>.
</dt>
</dl>
<h2><a name="examples"></a>Example(s)</h2>
The following C++ function applies a Python callable object to its two
arguments and returns the result. If a Python exception is raised or
the result can't be converted to a <code>double</code>, an exception
is thrown.
<pre>
double apply2(PyObject* func, double x, double y)
{
return boost::python::call<double>(func, x, y);
}
</pre>
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->
9 May, 2002 <!-- Luann's birthday! -->
<!--webbot bot="Timestamp" endspan i-checksum="39359" -->
</p>
<p><i>© Copyright <a href="http://www.boost.org/people/dave_abrahams.htm">Dave Abrahams</a>
2002. </i></p>
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