1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>invoke</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Fusion 2.2"> 8<link rel="up" href="../functions.html" title="Functions"> 9<link rel="prev" href="../functions.html" title="Functions"> 10<link rel="next" href="invoke_proc.html" title="invoke_procedure"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="../functions.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="invoke_proc.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="fusion.functional.invocation.functions.invoke"></a><a class="link" href="invoke.html" title="invoke">invoke</a> 28</h5></div></div></div> 29<h6> 30<a name="fusion.functional.invocation.functions.invoke.h0"></a> 31 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.description"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.description">Description</a> 32 </h6> 33<p> 34 Calls a <a class="link" href="../../concepts/def_callable.html" title="Deferred Callable Object">Deferred 35 Callable Object</a> with the arguments from a <a class="link" href="../../../sequence.html" title="Sequence">Sequence</a>. 36 </p> 37<p> 38 The first template parameter can be specialized explicitly to avoid copying 39 and/or to control the const qualification of a function object. 40 </p> 41<p> 42 If the target function is a pointer to a class members, the corresponding 43 object can be specified as a reference, pointer, or smart pointer. In 44 case of the latter, a freestanding <code class="literal">get_pointer</code> function 45 must be defined (Boost provides this function for <code class="literal">std::auto_ptr</code> 46 and <a href="http://www.boost.org/libs/smart_ptr#shared_ptr" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">shared_ptr</span></code></a>). 47 </p> 48<p> 49 Constructors can be called applying <a href="http://www.boost.org/libs/functional/factory" target="_top">Boost.Functional/Factory 50 Library</a>. 51 </p> 52<h6> 53<a name="fusion.functional.invocation.functions.invoke.h1"></a> 54 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.synopsis"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.synopsis">Synopsis</a> 55 </h6> 56<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 57 <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">,</span> 58 <span class="keyword">class</span> <span class="identifier">Sequence</span> 59 <span class="special">></span> 60<span class="keyword">typename</span> <a class="link" href="../metafunctions/invoke.html" title="invoke"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke</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> 61<span class="identifier">invoke</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> 62 63<span class="keyword">template</span><span class="special"><</span> 64 <span class="keyword">typename</span> <span class="identifier">Function</span><span class="special">,</span> 65 <span class="keyword">class</span> <span class="identifier">Sequence</span> 66 <span class="special">></span> 67<span class="keyword">typename</span> <a class="link" href="../metafunctions/invoke.html" title="invoke"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke</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> 68<span class="identifier">invoke</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> 69</pre> 70<h6> 71<a name="fusion.functional.invocation.functions.invoke.h2"></a> 72 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.parameters"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.parameters">Parameters</a> 73 </h6> 74<div class="informaltable"><table class="table"> 75<colgroup> 76<col> 77<col> 78<col> 79</colgroup> 80<thead><tr> 81<th> 82 <p> 83 Parameter 84 </p> 85 </th> 86<th> 87 <p> 88 Requirement 89 </p> 90 </th> 91<th> 92 <p> 93 Description 94 </p> 95 </th> 96</tr></thead> 97<tbody> 98<tr> 99<td> 100 <p> 101 <code class="computeroutput"><span class="identifier">f</span></code> 102 </p> 103 </td> 104<td> 105 <p> 106 A <a class="link" href="../../concepts/def_callable.html" title="Deferred Callable Object">Deferred 107 Callable Object</a> 108 </p> 109 </td> 110<td> 111 <p> 112 The function to call. 113 </p> 114 </td> 115</tr> 116<tr> 117<td> 118 <p> 119 <code class="computeroutput"><span class="identifier">s</span></code> 120 </p> 121 </td> 122<td> 123 <p> 124 A <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward 125 Sequence</a> 126 </p> 127 </td> 128<td> 129 <p> 130 The arguments. 131 </p> 132 </td> 133</tr> 134</tbody> 135</table></div> 136<h6> 137<a name="fusion.functional.invocation.functions.invoke.h3"></a> 138 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.expression_semantics"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.expression_semantics">Expression 139 Semantics</a> 140 </h6> 141<pre class="programlisting"><span class="identifier">invoke</span><span class="special">(</span><span class="identifier">f</span><span class="special">,</span><span class="identifier">s</span><span class="special">);</span> 142</pre> 143<p> 144 <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 145 <code class="computeroutput"><span class="identifier">s</span></code> as its arguments. 146 </p> 147<p> 148 <span class="bold"><strong>Semantics</strong></span>: Invokes <code class="computeroutput"><span class="identifier">f</span></code> 149 with the elements in <code class="computeroutput"><span class="identifier">s</span></code> 150 as arguments and returns the result of the call expression. 151 </p> 152<h6> 153<a name="fusion.functional.invocation.functions.invoke.h4"></a> 154 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.header"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.header">Header</a> 155 </h6> 156<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</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 157</pre> 158<h6> 159<a name="fusion.functional.invocation.functions.invoke.h5"></a> 160 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.example"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.example">Example</a> 161 </h6> 162<pre class="programlisting"><a href="http://en.cppreference.com/w/cpp/utility/functional/plus" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span></code></a><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">add</span><span class="special">;</span> 163<span class="identifier">assert</span><span class="special">(</span><span class="identifier">invoke</span><span class="special">(</span><span class="identifier">add</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">1</span><span class="special">,</span><span class="number">1</span><span class="special">))</span> <span class="special">==</span> <span class="number">2</span><span class="special">);</span> 164</pre> 165<h6> 166<a name="fusion.functional.invocation.functions.invoke.h6"></a> 167 <span class="phrase"><a name="fusion.functional.invocation.functions.invoke.see_also"></a></span><a class="link" href="invoke.html#fusion.functional.invocation.functions.invoke.see_also">See 168 also</a> 169 </h6> 170<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 171<li class="listitem"> 172 <a class="link" href="invoke_proc.html" title="invoke_procedure"><code class="computeroutput"><span class="identifier">invoke_procedure</span></code></a> 173 </li> 174<li class="listitem"> 175 <a class="link" href="invoke_fobj.html" title="invoke_function_object"><code class="computeroutput"><span class="identifier">invoke_function_object</span></code></a> 176 </li> 177<li class="listitem"> 178 <a class="link" href="../metafunctions/invoke.html" title="invoke"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">invoke</span></code></a> 179 </li> 180<li class="listitem"> 181 <a class="link" href="../../adapters/fused.html" title="fused"><code class="computeroutput"><span class="identifier">fused</span></code></a> 182 </li> 183<li class="listitem"> 184 <a class="link" href="../../generation/functions/mk_fused.html" title="make_fused"><code class="computeroutput"><span class="identifier">make_fused</span></code></a> 185 </li> 186</ul></div> 187</div> 188<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 189<td align="left"></td> 190<td align="right"><div class="copyright-footer">Copyright © 2001-2006, 2011, 2012 Joel de Guzman, 191 Dan Marsden, Tobias Schwinger<p> 192 Distributed under the Boost Software License, Version 1.0. (See accompanying 193 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>) 194 </p> 195</div></td> 196</tr></table> 197<hr> 198<div class="spirit-nav"> 199<a accesskey="p" href="../functions.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="invoke_proc.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 200</div> 201</body> 202</html> 203
