<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Concept CallableTransform</title> <link rel="stylesheet" href="boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="proto/reference.html" title="Reference"> <link rel="prev" href="boost/proto/context/null_context/eval.html" title="Struct template eval"> <link rel="next" href="ObjectTransform.html" title="Concept ObjectTransform"> </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 href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="boost/proto/context/null_context/eval.html"><img src="../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.html"><img src="../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="ObjectTransform.html"><img src="../../doc/html/images/next.png" alt="Next"></a> </div> <div class="refentry" title="Concept CallableTransform"> <a name="CallableTransform"></a><div class="titlepage"></div> <div class="refnamediv"> <h2><span class="refentrytitle">Concept CallableTransform</span></h2> <p>CallableTransform</p> </div> <div class="refsect1" title="Description"> <a name="id1681691"></a><h2>Description</h2> <p> A CallableTransform is a function type or a function pointer type where the return type Fn is a PolymorphicFunctionObject and the arguments are Transforms. is_callable< Fn >::value must be true. The CallableTransform, when applied, has the effect of invoking the polymorphic function object Fn, passing as arguments the result(s) of applying transform(s) Tn. </p> </div> <div class="refsect1" title="Associated types"> <a name="id1681702"></a><h2>Associated types</h2> <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> <p><span class="bold"><strong>result_type</strong></span></p> <pre class="literallayout">boost::result_of<Fn(Transform<Tn, Expr, State, Data>::result_type...)>::type</pre> <p> </p> <p>The result of applying the CallableTransform.</p> <p> </p> </li></ul></div> </div> <div class="refsect1" title="Notation"> <a name="id1681724"></a><h2>Notation</h2> <div class="variablelist"><dl> <dt><span class="term">Fn</span></dt> <dd>A type playing the role of polymorphic-function-object-type in the <a class="link" href="CallableTransform.html" title="Concept CallableTransform">CallableTransform</a> concept.</dd> <dt><span class="term">Tn</span></dt> <dd>A type playing the role of transform-type in the <a class="link" href="CallableTransform.html" title="Concept CallableTransform">CallableTransform</a> concept.</dd> <dt><span class="term">Expr</span></dt> <dd>A type playing the role of expression-type in the <a class="link" href="CallableTransform.html" title="Concept CallableTransform">CallableTransform</a> concept.</dd> <dt><span class="term">State</span></dt> <dd>A type playing the role of state-type in the <a class="link" href="CallableTransform.html" title="Concept CallableTransform">CallableTransform</a> concept.</dd> <dt><span class="term">Data</span></dt> <dd>A type playing the role of data-type in the <a class="link" href="CallableTransform.html" title="Concept CallableTransform">CallableTransform</a> concept.</dd> <dt><span class="term"><code class="varname">fn</code></span></dt> <dd>Object of type Fn</dd> <dt><span class="term"><code class="varname">expr</code></span></dt> <dd>Object of type Expr</dd> <dt><span class="term"><code class="varname">state</code></span></dt> <dd>Object of type State</dd> <dt><span class="term"><code class="varname">data</code></span></dt> <dd>Object of type Data</dd> </dl></div> </div> <div class="refsect1" title="Valid expressions"> <a name="id1681839"></a><h2>Valid expressions</h2> <div class="informaltable"><table class="table"> <colgroup> <col> <col> <col> <col> </colgroup> <thead><tr> <th>Name</th> <th>Expression</th> <th>Type</th> <th>Semantics</th> </tr></thead> <tbody><tr> <td><p>Apply Transform</p></td> <td><p>when< _, Fn(Tn...)>()(expr, state, data)</p></td> <td><p><span class="type">result_type</span></p></td> <td><p>Applies the transform.</p></td> </tr></tbody> </table></div> </div> <div class="refsect1" title="Models"> <a name="id1681877"></a><h2>Models</h2> <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><span class="simplelist"><span class="type">boost::proto::_child(boost::proto::_left)</span></span></li></ul></div> </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 © 2008 Eric Niebler<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="boost/proto/context/null_context/eval.html"><img src="../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.html"><img src="../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="ObjectTransform.html"><img src="../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>