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 impl</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="../_env_var.html#id-1.3.33.5.46.20.4" title="Description"> 10<link rel="prev" href="../_env_var.html" title="Struct template _env_var"> 11<link rel="next" href="../_env.html" title="Struct _env"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 16<td align="center"><a 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29<h2><span class="refentrytitle">Struct template impl</span></h2> 30<p>boost::proto::_env_var::impl</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<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.transform.env_hpp" title="Header <boost/proto/transform/env.hpp>">boost/proto/transform/env.hpp</a>> 34 35</span> 36 37<span class="keyword">struct</span> <a class="link" href="impl.html" title="Struct template impl">impl</a> <span class="special">:</span> <span class="keyword"></span> <a class="link" href="../transform_impl.html" title="Struct template transform_impl">proto::transform_impl</a><Expr, State, Data> > <span class="special">{</span> 38 <span class="comment">// types</span> 39 <span class="keyword">typedef</span> <span class="keyword">typename</span> <a class="link" href="../result_of/env_var.html" title="Struct template env_var">proto::result_of::env_var</a><span class="special"><</span><span class="identifier">Data</span><span class="special">,</span> <span class="identifier">Key</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span> <a name="boost.proto._env_var.impl.result_type"></a><span class="identifier">result_type</span><span class="special">;</span> 40 41 <span class="comment">// <a class="link" href="impl.html#id-1_3_33_5_44_1_1_13_4_4-bb">public member functions</a></span> 42 <span class="identifier">result_type</span> <a class="link" href="impl.html#id-1_3_33_5_44_1_1_13_4_4_1-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">expr_param</span><span class="special">,</span> 43 <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">state_param</span><span class="special">,</span> 44 <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">data_param</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 45<span class="special">}</span><span class="special">;</span></pre></div> 46<div class="refsect1"> 47<a name="id-1.3.33.5.46.20.4.3.4"></a><h2>Description</h2> 48<div class="refsect2"> 49<a name="id-1.3.33.5.46.20.4.3.4.2"></a><h3> 50<a name="id-1_3_33_5_44_1_1_13_4_4-bb"></a><code class="computeroutput">impl</code> public member functions</h3> 51<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 52<pre class="literallayout"><span class="identifier">result_type</span> <a name="id-1_3_33_5_44_1_1_13_4_4_1-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">expr_param</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">state_param</span><span class="special">,</span> 53 <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">data_param</span> data<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre> 54<p> 55 Fetches the value associated with <code class="computeroutput">Key</code> from the transform environment 56 passed in the data (third) parameter. 57 </p> 58<div class="variablelist"><table border="0" class="variablelist compact"> 59<colgroup> 60<col align="left" valign="top"> 61<col> 62</colgroup> 63<tbody> 64<tr> 65<td><p><span class="term">Parameters:</span></p></td> 66<td><div class="variablelist"><table border="0" class="variablelist compact"> 67<colgroup> 68<col align="left" valign="top"> 69<col> 70</colgroup> 71<tbody><tr> 72<td><p><span class="term"><code class="computeroutput">data</code></span></p></td> 73<td><p>The current transform environment</p></td> 74</tr></tbody> 75</table></div></td> 76</tr> 77<tr> 78<td><p><span class="term">Requires:</span></p></td> 79<td><p> 80 <code class="computeroutput"><a class="link" href="../is_env.html" title="Struct template is_env">proto::is_env</a><Data>::value</code> 81 is <code class="computeroutput">true</code>. 82 </p></td> 83</tr> 84<tr> 85<td><p><span class="term">Returns:</span></p></td> 86<td><p> 87 <code class="computeroutput"><a class="link" href="../env_var.html" title="Function env_var">proto::env_var</a>(data)</code> 88 </p></td> 89</tr> 90</tbody> 91</table></div> 92</li></ol></div> 93</div> 94</div> 95</div> 96<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 97<td align="left"></td> 98<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 99 Distributed under the Boost Software License, Version 1.0. (See accompanying 100 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>) 101 </p> 102</div></td> 103</tr></table> 104<hr> 105<div class="spirit-nav"> 106<a accesskey="p" href="../_env_var.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../_env_var.html#id-1.3.33.5.46.20.4"><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="../_env.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 107</div> 108</body> 109</html> 110
