1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Struct template compose_generators</title> 6<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../../proto/reference.html#header.boost.proto.generate_hpp" title="Header <boost/proto/generate.hpp>"> 10<link rel="prev" href="by_value_generator/result_1_3_33_5_29_2_1_5_4.html" title="Struct template result<This(Expr)>"> 11<link rel="next" href="compose_generators/result_1_3_33_5_29_2_1_6_5.html" title="Struct template result<This(Expr)>"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 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href="compose_generators/result_1_3_33_5_29_2_1_6_5.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.proto.compose_generators"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Struct template compose_generators</span></h2> 30<p>boost::proto::compose_generators — A composite generator that first applies one transform to an expression and then forwards 31 the result on to another generator for further transformation.</p> 32</div> 33<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 34<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../proto/reference.html#header.boost.proto.generate_hpp" title="Header <boost/proto/generate.hpp>">boost/proto/generate.hpp</a>> 35 36</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> First<span class="special">,</span> <span class="keyword">typename</span> Second<span class="special">></span> 37<span class="keyword">struct</span> <a class="link" href="compose_generators.html" title="Struct template compose_generators">compose_generators</a> <span class="special">:</span> <span class="keyword"></span> <a class="link" href="callable.html" title="Struct callable">proto::callable</a> <span class="special">{</span> 38 <span class="comment">// member classes/structs/unions</span> 39 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> This<span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../../Expr.html" title="Concept Expr">Expr</a><span class="special">></span> 40 <span class="keyword">struct</span> <a class="link" href="compose_generators/result_1_3_33_5_29_2_1_6_5.html" title="Struct template result<This(Expr)>">result</a><span class="special"><</span><span class="identifier">This</span><span class="special">(</span><span class="identifier">Expr</span><span class="special">)</span><span class="special">></span> <span class="special">:</span> <span class="keyword"></span> 41 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span> 42 <span class="identifier">Second</span><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span><span class="identifier">First</span><span class="special">(</span><span class="identifier">Expr</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span><span class="special">)</span> 43 <span class="special">></span> 44 <span class="special">{</span> 45 <span class="special">}</span><span class="special">;</span> 46 47 <span class="comment">// <a class="link" href="compose_generators.html#id-1_3_33_5_29_2_1_6_6-bb">public member functions</a></span> 48 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../../Expr.html" title="Concept Expr">Expr</a><span class="special">></span> 49 <span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span> 50 <span class="identifier">Second</span><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span><span class="identifier">First</span><span class="special">(</span><span class="identifier">Expr</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span><span class="special">)</span> 51 <span class="special">></span><span class="special">::</span><span class="identifier">type</span> 52 <a class="link" href="compose_generators.html#id-1_3_33_5_29_2_1_6_6_1-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">Expr</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 53<span class="special">}</span><span class="special">;</span></pre></div> 54<div class="refsect1"> 55<a name="id-1.3.33.5.31.9.4"></a><h2>Description</h2> 56<p> 57 Generators are intended for use as the first template parameter to the 58 <code class="computeroutput"><a class="link" href="domain.html" title="Struct template domain">proto::domain<></a></code> 59 class template and control if and how expressions within that domain are to be customized. 60 <code class="computeroutput">proto::compose_generators<></code> is a composite generator 61 that first applies one transform to an expression and then forwards the result on to another 62 generator for further transformation. 63 </p> 64<div class="refsect2"> 65<a name="id-1.3.33.5.31.9.4.3"></a><h3> 66<a name="id-1_3_33_5_29_2_1_6_6-bb"></a><code class="computeroutput">compose_generators</code> public member functions</h3> 67<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 68<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../../Expr.html" title="Concept Expr">Expr</a><span class="special">></span> 69 <span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span> 70 <span class="identifier">Second</span><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span><span class="special"><</span><span class="identifier">First</span><span class="special">(</span><span class="identifier">Expr</span><span class="special">)</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span><span class="special">)</span> 71 <span class="special">></span><span class="special">::</span><span class="identifier">type</span> 72 <a name="id-1_3_33_5_29_2_1_6_6_1-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">Expr</span> <span class="keyword">const</span> <span class="special">&</span> expr<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre> 73<div class="variablelist"><table border="0" class="variablelist compact"> 74<colgroup> 75<col align="left" valign="top"> 76<col> 77</colgroup> 78<tbody> 79<tr> 80<td><p><span class="term">Parameters:</span></p></td> 81<td><div class="variablelist"><table border="0" class="variablelist compact"> 82<colgroup> 83<col align="left" valign="top"> 84<col> 85</colgroup> 86<tbody><tr> 87<td><p><span class="term"><code class="computeroutput">expr</code></span></p></td> 88<td><p>A Proto expression.</p></td> 89</tr></tbody> 90</table></div></td> 91</tr> 92<tr> 93<td><p><span class="term">Returns:</span></p></td> 94<td><p><code class="computeroutput">Second()(First()(expr))</code></p></td> 95</tr> 96</tbody> 97</table></div> 98</li></ol></div> 99</div> 100</div> 101</div> 102<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 103<td align="left"></td> 104<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 105 Distributed under the Boost Software License, Version 1.0. (See accompanying 106 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>) 107 </p> 108</div></td> 109</tr></table> 110<hr> 111<div class="spirit-nav"> 112<a accesskey="p" href="by_value_generator/result_1_3_33_5_29_2_1_5_4.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.generate_hpp"><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="compose_generators/result_1_3_33_5_29_2_1_6_5.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 113</div> 114</body> 115</html> 116
