1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Class template attribute_value_impl</title> 5<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Chapter 1. Boost.Log v2"> 8<link rel="up" href="../../../attributes.html#header.boost.log.attributes.attribute_value_impl_hpp" title="Header <boost/log/attributes/attribute_value_impl.hpp>"> 9<link rel="prev" href="../swap_idm46079579643808.html" title="Function swap"> 10<link rel="next" href="make_attribute_value.html" title="Function template make_attribute_value"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td></tr></table> 14<hr> 15<div class="spirit-nav"> 16<a accesskey="p" href="../swap_idm46079579643808.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../attributes.html#header.boost.log.attributes.attribute_value_impl_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="make_attribute_value.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 17</div> 18<div class="refentry"> 19<a name="boost.log.attributes.attribute_value_impl"></a><div class="titlepage"></div> 20<div class="refnamediv"> 21<h2><span class="refentrytitle">Class template attribute_value_impl</span></h2> 22<p>boost::log::attributes::attribute_value_impl — Basic attribute value implementation class. </p> 23</div> 24<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 25<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="../../../attributes.html#header.boost.log.attributes.attribute_value_impl_hpp" title="Header <boost/log/attributes/attribute_value_impl.hpp>">boost/log/attributes/attribute_value_impl.hpp</a>> 26 27</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> 28<span class="keyword">class</span> <a class="link" href="attribute_value_impl.html" title="Class template attribute_value_impl">attribute_value_impl</a> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">attribute_value</span><span class="special">::</span><span class="identifier">impl</span> <span class="special">{</span> 29<span class="keyword">public</span><span class="special">:</span> 30 <span class="comment">// types</span> 31 <span class="keyword">typedef</span> <span class="identifier">T</span> <a name="boost.log.attributes.attribute_value_impl.value_type"></a><span class="identifier">value_type</span><span class="special">;</span> <span class="comment">// Value type. </span> 32 33 <span class="comment">// <a class="link" href="attribute_value_impl.html#boost.log.attributes.attribute_value_implconstruct-copy-destruct">construct/copy/destruct</a></span> 34 <span class="keyword">explicit</span> <a class="link" href="attribute_value_impl.html#idm46079579623200-bb"><span class="identifier">attribute_value_impl</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 35 <span class="keyword">explicit</span> <a class="link" href="attribute_value_impl.html#idm46079579621504-bb"><span class="identifier">attribute_value_impl</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="special">&&</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span> <span class="identifier">value_type</span> <span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 36 37 <span class="comment">// <a class="link" href="attribute_value_impl.html#idm46079579632752-bb">public member functions</a></span> 38 <span class="keyword">virtual</span> <span class="keyword">bool</span> <a class="link" href="attribute_value_impl.html#idm46079579632192-bb"><span class="identifier">dispatch</span></a><span class="special">(</span><span class="identifier">type_dispatcher</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 39 <span class="keyword">virtual</span> <span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">type_index</span> <a class="link" href="attribute_value_impl.html#idm46079579627888-bb"><span class="identifier">get_type</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 40 <span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&</span> <a class="link" href="attribute_value_impl.html#idm46079579625488-bb"><span class="identifier">get</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 41<span class="special">}</span><span class="special">;</span></pre></div> 42<div class="refsect1"> 43<a name="idm44984884533232"></a><h2>Description</h2> 44<p>This class can be used as a boilerplate for simple attribute values. The class implements all needed interfaces of attribute values and allows to store a single value of the type specified as a template parameter. The stored value can be dispatched with type dispatching mechanism. </p> 45<div class="refsect2"> 46<a name="idm44984884532256"></a><h3> 47<a name="boost.log.attributes.attribute_value_implconstruct-copy-destruct"></a><code class="computeroutput">attribute_value_impl</code> 48 public 49 construct/copy/destruct</h3> 50<div class="orderedlist"><ol class="orderedlist" type="1"> 51<li class="listitem"> 52<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm46079579623200-bb"></a><span class="identifier">attribute_value_impl</span><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&</span> v<span class="special">)</span><span class="special">;</span></pre> 53<p>Constructor with initialization of the stored value </p> 54</li> 55<li class="listitem"> 56<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm46079579621504-bb"></a><span class="identifier">attribute_value_impl</span><span class="special">(</span><span class="identifier">value_type</span> <span class="special">&&</span> v<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_nothrow_move_constructible</span><span class="special"><</span> <span class="identifier">value_type</span> <span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre> 57<p>Constructor with initialization of the stored value </p> 58</li> 59</ol></div> 60</div> 61<div class="refsect2"> 62<a name="idm44984884510112"></a><h3> 63<a name="idm46079579632752-bb"></a><code class="computeroutput">attribute_value_impl</code> public member functions</h3> 64<div class="orderedlist"><ol class="orderedlist" type="1"> 65<li class="listitem"> 66<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">bool</span> <a name="idm46079579632192-bb"></a><span class="identifier">dispatch</span><span class="special">(</span><span class="identifier">type_dispatcher</span> <span class="special">&</span> dispatcher<span class="special">)</span><span class="special">;</span></pre> 67<p>Attribute value dispatching method.</p> 68<p> 69 70</p> 71<div class="variablelist"><table border="0" class="variablelist compact"> 72<colgroup> 73<col align="left" valign="top"> 74<col> 75</colgroup> 76<tbody> 77<tr> 78<td><p><span class="term">Parameters:</span></p></td> 79<td><div class="variablelist"><table border="0" class="variablelist compact"> 80<colgroup> 81<col align="left" valign="top"> 82<col> 83</colgroup> 84<tbody><tr> 85<td><p><span class="term"><code class="computeroutput">dispatcher</code></span></p></td> 86<td><p>The dispatcher that receives the stored value</p></td> 87</tr></tbody> 88</table></div></td> 89</tr> 90<tr> 91<td><p><span class="term">Returns:</span></p></td> 92<td><p><code class="computeroutput">true</code> if the value has been dispatched, <code class="computeroutput">false</code> otherwise </p></td> 93</tr> 94</tbody> 95</table></div> 96</li> 97<li class="listitem"> 98<pre class="literallayout"><span class="keyword">virtual</span> <span class="identifier">typeindex</span><span class="special">::</span><span class="identifier">type_index</span> <a name="idm46079579627888-bb"></a><span class="identifier">get_type</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre> 99<p> 100</p> 101<div class="variablelist"><table border="0" class="variablelist compact"> 102<colgroup> 103<col align="left" valign="top"> 104<col> 105</colgroup> 106<tbody><tr> 107<td><p><span class="term">Returns:</span></p></td> 108<td><p>The attribute value type </p></td> 109</tr></tbody> 110</table></div> 111</li> 112<li class="listitem"> 113<pre class="literallayout"><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&</span> <a name="idm46079579625488-bb"></a><span class="identifier">get</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre> 114<p> 115</p> 116<div class="variablelist"><table border="0" class="variablelist compact"> 117<colgroup> 118<col align="left" valign="top"> 119<col> 120</colgroup> 121<tbody><tr> 122<td><p><span class="term">Returns:</span></p></td> 123<td><p>Reference to the contained value. </p></td> 124</tr></tbody> 125</table></div> 126</li> 127</ol></div> 128</div> 129</div> 130</div> 131<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 132<td align="left"></td> 133<td align="right"><div class="copyright-footer">Copyright © 2007-2019 Andrey Semashev<p> 134 Distributed under the Boost Software License, Version 1.0. (See accompanying 135 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>). 136 </p> 137</div></td> 138</tr></table> 139<hr> 140<div class="spirit-nav"> 141<a accesskey="p" href="../swap_idm46079579643808.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../attributes.html#header.boost.log.attributes.attribute_value_impl_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="make_attribute_value.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 142</div> 143</body> 144</html> 145
