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>Class value_semantic</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="../../program_options/reference.html#header.boost.program_options.value_semantic_hpp" title="Header <boost/program_options/value_semantic.hpp>"> 10<link rel="prev" href="untyped_value.html" title="Class untyped_value"> 11<link rel="next" href="value_se_1_3_31_9_10_1_1_5.html" title="Class template value_semantic_codecvt_helper"> 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 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alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.program_options.value_semantic"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class value_semantic</span></h2> 30<p>boost::program_options::value_semantic</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="../../program_options/reference.html#header.boost.program_options.value_semantic_hpp" title="Header <boost/program_options/value_semantic.hpp>">boost/program_options/value_semantic.hpp</a>> 34 35</span> 36<span class="keyword">class</span> <a class="link" href="value_semantic.html" title="Class value_semantic">value_semantic</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// <a class="link" href="value_semantic.html#boost.program_options.value_semanticconstruct-copy-destruct">construct/copy/destruct</a></span> 39 <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_3-bb"><span class="special">~</span><span class="identifier">value_semantic</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 40 41 <span class="comment">// <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2-bb">public member functions</a></span> 42 <span class="keyword">virtual</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_1-bb"><span class="identifier">name</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 43 <span class="keyword">virtual</span> <span class="keyword">unsigned</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_2-bb"><span class="identifier">min_tokens</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 44 <span class="keyword">virtual</span> <span class="keyword">unsigned</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_3-bb"><span class="identifier">max_tokens</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 45 <span class="keyword">virtual</span> <span class="keyword">bool</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_4-bb"><span class="identifier">is_composing</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 46 <span class="keyword">virtual</span> <span class="keyword">bool</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_5-bb"><span class="identifier">is_required</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 47 <span class="keyword">virtual</span> <span class="keyword">void</span> 48 <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_6-bb"><span class="identifier">parse</span></a><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">bool</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 49 <span class="keyword">virtual</span> <span class="keyword">bool</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_7-bb"><span class="identifier">apply_default</span></a><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 50 <span class="keyword">virtual</span> <span class="keyword">void</span> <a class="link" href="value_semantic.html#id-1_3_31_9_10_1_1_4_2_8-bb"><span class="identifier">notify</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 51<span class="special">}</span><span class="special">;</span></pre></div> 52<div class="refsect1"> 53<a name="id-1.3.31.9.11.6.4"></a><h2>Description</h2> 54<p>Class which specifies how the option's value is to be parsed and converted into C++ types. </p> 55<div class="refsect2"> 56<a name="id-1.3.31.9.11.6.4.3"></a><h3> 57<a name="boost.program_options.value_semanticconstruct-copy-destruct"></a><code class="computeroutput">value_semantic</code> 58 public 59 construct/copy/destruct</h3> 60<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><pre class="literallayout"><a name="id-1_3_31_9_10_1_1_4_3-bb"></a><span class="special">~</span><span class="identifier">value_semantic</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre></li></ol></div> 61</div> 62<div class="refsect2"> 63<a name="id-1.3.31.9.11.6.4.4"></a><h3> 64<a name="id-1_3_31_9_10_1_1_4_2-bb"></a><code class="computeroutput">value_semantic</code> public member functions</h3> 65<div class="orderedlist"><ol class="orderedlist" type="1"> 66<li class="listitem"> 67<pre class="literallayout"><span class="keyword">virtual</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <a name="id-1_3_31_9_10_1_1_4_2_1-bb"></a><span class="identifier">name</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 68<p>Returns the name of the option. The name is only meaningful for automatic help message. </p> 69</li> 70<li class="listitem"> 71<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">unsigned</span> <a name="id-1_3_31_9_10_1_1_4_2_2-bb"></a><span class="identifier">min_tokens</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 72<p>The minimum number of tokens for this option that should be present on the command line. </p> 73</li> 74<li class="listitem"> 75<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">unsigned</span> <a name="id-1_3_31_9_10_1_1_4_2_3-bb"></a><span class="identifier">max_tokens</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 76<p>The maximum number of tokens for this option that should be present on the command line. </p> 77</li> 78<li class="listitem"> 79<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">bool</span> <a name="id-1_3_31_9_10_1_1_4_2_4-bb"></a><span class="identifier">is_composing</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 80<p>Returns true if values from different sources should be composed. Otherwise, value from the first source is used and values from other sources are discarded. </p> 81</li> 82<li class="listitem"> 83<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">bool</span> <a name="id-1_3_31_9_10_1_1_4_2_5-bb"></a><span class="identifier">is_required</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 84<p>Returns true if value must be given. Non-optional value </p> 85</li> 86<li class="listitem"> 87<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">void</span> 88<a name="id-1_3_31_9_10_1_1_4_2_6-bb"></a><span class="identifier">parse</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span> value_store<span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">></span> <span class="special">&</span> new_tokens<span class="special">,</span> 89 <span class="keyword">bool</span> utf8<span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 90<p>Parses a group of tokens that specify a value of option. Stores the result in 'value_store', using whatever representation is desired. May be be called several times if value of the same option is specified more than once. </p> 91</li> 92<li class="listitem"> 93<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">bool</span> <a name="id-1_3_31_9_10_1_1_4_2_7-bb"></a><span class="identifier">apply_default</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span> value_store<span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 94<p>Called to assign default value to 'value_store'. Returns true if default value is assigned, and false if no default value exists. </p> 95</li> 96<li class="listitem"> 97<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">void</span> <a name="id-1_3_31_9_10_1_1_4_2_8-bb"></a><span class="identifier">notify</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">any</span> <span class="special">&</span> value_store<span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 98<p>Called when final value of an option is determined. </p> 99</li> 100</ol></div> 101</div> 102</div> 103</div> 104<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 105<td align="left"></td> 106<td align="right"><div class="copyright-footer">Copyright © 2002-2004 Vladimir Prus<p>Distributed under the Boost Software License, Version 1.0. 107 (See accompanying file <code class="filename">LICENSE_1_0.txt</code> or copy at 108 <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 109 </p> 110</div></td> 111</tr></table> 112<hr> 113<div class="spirit-nav"> 114<a accesskey="p" href="untyped_value.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../program_options/reference.html#header.boost.program_options.value_semantic_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="value_se_1_3_31_9_10_1_1_5.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 115</div> 116</body> 117</html> 118
