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>Function has_env_var</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.transform.env_hpp" title="Header <boost/proto/transform/env.hpp>"> 10<link rel="prev" href="as_env.html" title="Function as_env"> 11<link rel="next" href="env_var.html" title="Function env_var"> 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 href="../../../../index.html">Home</a></td> 17<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="as_env.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.transform.env_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="env_var.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.proto.has_env_var"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Function has_env_var</span></h2> 30<p>boost::proto::has_env_var — 31 For testing to see whether a value exists in a transform environment corresponding to the 32 specified <code class="computeroutput">Key</code>. 33 </p> 34</div> 35<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 36<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>> 37 38</span> 39<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Key<span class="special">,</span> <span class="keyword">typename</span> Env<span class="special">></span> 40 <span class="keyword">typename</span> <a class="link" href="result_of/has_env_var.html" title="Struct template has_env_var">proto::result_of::has_env_var</a><span class="special"><</span><span class="identifier">Env</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Key</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span> 41 <span class="identifier">has_env_var</span><span class="special">(</span><span class="identifier">Env</span> <span class="special">&</span> e<span class="special">)</span><span class="special">;</span> 42<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Key<span class="special">,</span> <span class="keyword">typename</span> Env<span class="special">></span> 43 <span class="keyword">typename</span> <a class="link" href="result_of/has_env_var.html" title="Struct template has_env_var">proto::result_of::has_env_var</a><span class="special"><</span><span class="identifier">Env</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Key</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span> 44 <span class="identifier">has_env_var</span><span class="special">(</span><span class="identifier">Env</span> <span class="keyword">const</span> <span class="special">&</span> e<span class="special">)</span><span class="special">;</span></pre></div> 45<div class="refsect1"> 46<a name="id-1.3.33.5.46.17.4"></a><h2>Description</h2> 47<p> 48 See also: 49 </p> 50<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><code class="computeroutput"><a class="link" href="functional/has_env_var.html#id-1_3_33_5_44_1_1_7_2_5_1-bb">proto::functional::has_env_var::operator()</a></code></li></ul></div> 51<p> 52 </p> 53<div class="variablelist"><table border="0" class="variablelist compact"> 54<colgroup> 55<col align="left" valign="top"> 56<col> 57</colgroup> 58<tbody><tr> 59<td><p><span class="term">Returns:</span></p></td> 60<td><code class="computeroutput"><a class="link" href="functional/has_env_var.html" title="Struct template has_env_var">proto::functional::has_env_var<Key></a>()(e)</code></td> 61</tr></tbody> 62</table></div> 63</div> 64</div> 65<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 66<td align="left"></td> 67<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 68 Distributed under the Boost Software License, Version 1.0. (See accompanying 69 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>) 70 </p> 71</div></td> 72</tr></table> 73<hr> 74<div class="spirit-nav"> 75<a accesskey="p" href="as_env.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.transform.env_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="env_var.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 76</div> 77</body> 78</html> 79
