<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>invoke_function_object</title> <link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../../../../index.html" title="Chapter 1. Fusion 2.0"> <link rel="up" href="../functions.html" title="Functions"> <link rel="prev" href="invoke_proc.html" title="invoke_procedure"> <link rel="next" href="../metafunctions.html" title="Metafunctions"> </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 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</h5></div></div></div> <a name="fusion.functional.invocation.functions.invoke_fobj.description"></a><h6> <a name="id1110464"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.description">Description</a> </h6> <p> Calls a <a class="link" href="../../concepts/poly.html" title="Polymorphic Function Object">Polymorphic Function Object</a> with the arguments from a <a class="link" href="../../../sequence.html" title="Sequence">Sequence</a>. </p> <p> The first template parameter can be specialized explicitly to avoid copying and/or to control the const qualification of a function object. </p> <p> Constructors can be called applying <a href="http://www.boost.org/libs/functional/factory/doc/html/index.html" target="_top">Boost.Functional/Factory</a>. </p> <a name="fusion.functional.invocation.functions.invoke_fobj.synopsis"></a><h6> <a name="id1110507"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.synopsis">Synopsis</a> </h6> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Sequence</span> <span class="special">></span> <span class="keyword">typename</span> <a class="link" href="../metafunctions/invoke_fobj.html" title="invoke_function_object"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke_function_object</span></code></a><span class="special"><</span><span class="identifier">Function</span><span class="special">,</span> <span class="identifier">Sequence</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">invoke_function_object</span><span class="special">(</span><span class="identifier">Function</span> <span class="identifier">f</span><span class="special">,</span> <span class="identifier">Sequence</span> <span class="special">&</span> <span class="identifier">s</span><span class="special">);</span> <span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Sequence</span> <span class="special">></span> <span class="keyword">typename</span> <a class="link" href="../metafunctions/invoke_fobj.html" title="invoke_function_object"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke_function_object</span></code></a><span class="special"><</span><span class="identifier">Function</span><span class="special">,</span> <span class="identifier">Sequence</span> <span class="keyword">const</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">invoke_function_object</span><span class="special">(</span><span class="identifier">Function</span> <span class="identifier">f</span><span class="special">,</span> <span class="identifier">Sequence</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">s</span><span class="special">);</span> </pre> <a name="fusion.functional.invocation.functions.invoke_fobj.parameters"></a><h6> <a name="id1110776"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.parameters">Parameters</a> </h6> <div class="informaltable"><table class="table"> <colgroup> <col> <col> <col> </colgroup> <thead><tr> <th> <p> Parameter </p> </th> <th> <p> Requirement </p> </th> <th> <p> Description </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">f</span></code> </p> </td> <td> <p> Model of <a class="link" href="../../concepts/poly.html" title="Polymorphic Function Object">Polymorphic Function Object</a> </p> </td> <td> <p> The function object to call. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">s</span></code> </p> </td> <td> <p> Model of <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> <p> The arguments. </p> </td> </tr> </tbody> </table></div> <a name="fusion.functional.invocation.functions.invoke_fobj.expression_semantics"></a><h6> <a name="id1110909"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.expression_semantics">Expression Semantics</a> </h6> <pre class="programlisting"><span class="identifier">invoke_function_object</span><span class="special">(</span><span class="identifier">f</span><span class="special">,</span><span class="identifier">s</span><span class="special">);</span> </pre> <p> <span class="bold"><strong>Return type</strong></span>: Return type of <code class="computeroutput"><span class="identifier">f</span></code> when invoked with the elements in <code class="computeroutput"><span class="identifier">s</span></code> as its arguments. </p> <p> <span class="bold"><strong>Semantics</strong></span>: Invokes <code class="computeroutput"><span class="identifier">f</span></code> with the elements in <code class="computeroutput"><span class="identifier">s</span></code> as arguments and returns the result of the call expression. </p> <a name="fusion.functional.invocation.functions.invoke_fobj.header"></a><h6> <a name="id1110996"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.header">Header</a> </h6> <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">functional</span><span class="special">/</span><span class="identifier">invocation</span><span class="special">/</span><span class="identifier">invoke_function_object</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> </pre> <a name="fusion.functional.invocation.functions.invoke_fobj.example"></a><h6> <a name="id1111071"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.example">Example</a> </h6> <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">sub</span> <span class="special">{</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Sig</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">result</span><span class="special">;</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Self</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">result</span><span class="special"><</span> <span class="identifier">Self</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> <span class="special">{</span> <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">remove_reference</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">type</span><span class="special">;</span> <span class="special">};</span> <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="identifier">T</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">T</span> <span class="identifier">lhs</span><span class="special">,</span> <span class="identifier">T</span> <span class="identifier">rhs</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">lhs</span> <span class="special">-</span> <span class="identifier">rhs</span><span class="special">;</span> <span class="special">}</span> <span class="special">};</span> <span class="keyword">void</span> <span class="identifier">try_it</span><span class="special">()</span> <span class="special">{</span> <span class="identifier">sub</span> <span class="identifier">f</span><span class="special">;</span> <span class="identifier">assert</span><span class="special">(</span><span class="identifier">f</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">1</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">invoke_function_object</span><span class="special">(</span><span class="identifier">f</span><span class="special">,</span><a class="link" href="../../../container/generation/functions/make_vector.html" title="make_vector"><code class="computeroutput"><span class="identifier">make_vector</span></code></a><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">1</span><span class="special">)));</span> <span class="special">}</span> </pre> <a name="fusion.functional.invocation.functions.invoke_fobj.see_also"></a><h6> <a name="id1111478"></a> <a class="link" href="invoke_fobj.html#fusion.functional.invocation.functions.invoke_fobj.see_also">See also</a> </h6> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <a class="link" href="invoke.html" title="invoke"><code class="computeroutput"><span class="identifier">invoke</span></code></a> </li> <li class="listitem"> <a class="link" href="invoke_proc.html" title="invoke_procedure"><code class="computeroutput"><span class="identifier">invoke_procedure</span></code></a> </li> <li class="listitem"> <a class="link" href="../metafunctions/invoke_fobj.html" title="invoke_function_object"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke_function_object</span></code></a> </li> <li class="listitem"> <a class="link" href="../../adapters/fused_function_object.html" title="fused_function_object"><code class="computeroutput"><span class="identifier">fused_function_object</span></code></a> </li> <li class="listitem"> <a class="link" href="../../generation/functions/mk_fused_fobj.html" title="make_fused_function_object"><code class="computeroutput"><span class="identifier">make_fused_function_object</span></code></a> </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 © 2001-2007 Joel de Guzman, Dan Marsden, Tobias Schwinger<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="invoke_proc.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../functions.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="../metafunctions.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>