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 value</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.traits_hpp" title="Header <boost/proto/traits.hpp>"> 10<link rel="prev" href="child_c.html" title="Function child_c"> 11<link rel="next" href="left.html" title="Function left"> 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="child_c.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.traits_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="left.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.proto.value"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Function value</span></h2> 30<p>boost::proto::value — Return the value stored within the specified Proto terminal expression. </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.traits_hpp" title="Header <boost/proto/traits.hpp>">boost/proto/traits.hpp</a>> 34 35</span> 36<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> 37 <span class="keyword">typename</span> <a class="link" href="result_of/value.html" title="Struct template value">proto::result_of::value</a><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="identifier">value</span><span class="special">(</span><span class="identifier">Expr</span> <span class="special">&</span> expr<span class="special">)</span><span class="special">;</span> 38<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> 39 <span class="keyword">typename</span> <a class="link" href="result_of/value.html" title="Struct template value">proto::result_of::value</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="special">::</span><span class="identifier">type</span> 40 <span class="identifier">value</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="special">;</span></pre></div> 41<div class="refsect1"> 42<a name="id-1.3.33.5.41.77.4"></a><h2>Description</h2> 43<p> 44 Return the the value stored within the specified Proto terminal expression. The value is 45 returned by reference. 46 </p> 47<div class="variablelist"><table border="0" class="variablelist compact"> 48<colgroup> 49<col align="left" valign="top"> 50<col> 51</colgroup> 52<tbody> 53<tr> 54<td><p><span class="term">Requires:</span></p></td> 55<td><p> 56 <code class="computeroutput">0 == Expr::proto_arity::value</code> 57 </p></td> 58</tr> 59<tr> 60<td><p><span class="term">Returns:</span></p></td> 61<td><p>A reference to the terminal's value </p></td> 62</tr> 63<tr> 64<td><p><span class="term">Throws:</span></p></td> 65<td>Will not throw.</td> 66</tr> 67</tbody> 68</table></div> 69</div> 70</div> 71<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 72<td align="left"></td> 73<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 74 Distributed under the Boost Software License, Version 1.0. (See accompanying 75 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>) 76 </p> 77</div></td> 78</tr></table> 79<hr> 80<div class="spirit-nav"> 81<a accesskey="p" href="child_c.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.traits_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="left.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 82</div> 83</body> 84</html> 85
