1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Class template basic_custom_mapping</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="../../../sinks.html#header.boost.log.sinks.attribute_mapping_hpp" title="Header <boost/log/sinks/attribute_mapping.hpp>"> 9<link rel="prev" href="asynchronous_sink/scoped_thread_id.html" title="Class scoped_thread_id"> 10<link rel="next" href="basic_direct_mapping.html" title="Class template basic_direct_mapping"> 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="asynchronous_sink/scoped_thread_id.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../sinks.html#header.boost.log.sinks.attribute_mapping_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="basic_direct_mapping.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 17</div> 18<div class="refentry"> 19<a name="boost.log.sinks.basic_custom_mapping"></a><div class="titlepage"></div> 20<div class="refnamediv"> 21<h2><span class="refentrytitle">Class template basic_custom_mapping</span></h2> 22<p>boost::log::sinks::basic_custom_mapping — Customizable mapping. </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="../../../sinks.html#header.boost.log.sinks.attribute_mapping_hpp" title="Header <boost/log/sinks/attribute_mapping.hpp>">boost/log/sinks/attribute_mapping.hpp</a>> 26 27</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> MappedT<span class="special">,</span> <span class="keyword">typename</span> AttributeValueT <span class="special">=</span> <span class="keyword">int</span><span class="special">></span> 28<span class="keyword">class</span> <a class="link" href="basic_custom_mapping.html" title="Class template basic_custom_mapping">basic_custom_mapping</a> <span class="special">:</span> 29 <span class="keyword">public</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">log</span><span class="special">::</span><span class="identifier">sinks</span><span class="special">::</span><span class="identifier">basic_mapping</span><span class="special"><</span> <span class="identifier">MappedT</span> <span class="special">></span> 30<span class="special">{</span> 31<span class="keyword">public</span><span class="special">:</span> 32 <span class="comment">// types</span> 33 <span class="keyword">typedef</span> <span class="identifier">AttributeValueT</span> <a name="boost.log.sinks.basic_custom_mapping.attribute_value_type"></a><span class="identifier">attribute_value_type</span><span class="special">;</span> <span class="comment">// Attribute contained value type. </span> 34 <span class="keyword">typedef</span> <span class="identifier">base_type</span><span class="special">::</span><span class="identifier">mapped_type</span> <a name="boost.log.sinks.basic_custom_mapping.mapped_type"></a><span class="identifier">mapped_type</span><span class="special">;</span> <span class="comment">// Mapped value type. </span> 35 36 <span class="comment">// <a class="link" href="basic_custom_mapping.html#boost.log.sinks.basic_custom_mappingconstruct-copy-destruct">construct/copy/destruct</a></span> 37 <span class="keyword">explicit</span> <a class="link" href="basic_custom_mapping.html#idm46079576945648-bb"><span class="identifier">basic_custom_mapping</span></a><span class="special">(</span><span class="identifier">attribute_name</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">mapped_type</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 38 39 <span class="comment">// <a class="link" href="basic_custom_mapping.html#idm46079576953920-bb">public member functions</a></span> 40 <span class="identifier">mapped_type</span> <a class="link" href="basic_custom_mapping.html#idm46079576953360-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">record_view</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 41 <span class="identifier">implementation_defined</span> <a class="link" href="basic_custom_mapping.html#idm46079576949680-bb"><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span></a><span class="special">(</span><span class="identifier">attribute_value_type</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 42<span class="special">}</span><span class="special">;</span></pre></div> 43<div class="refsect1"> 44<a name="idm44984865860256"></a><h2>Description</h2> 45<p>The class allows to setup a custom mapping between an attribute and native values. The mapping should be initialized similarly to the standard <code class="computeroutput">map</code> container, by using indexing operator and assignment.</p> 46<div class="note"><table border="0" summary="Note"> 47<tr> 48<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td> 49<th align="left">Note</th> 50</tr> 51<tr><td align="left" valign="top"><p>Unlike many other components of the library, exact type of the attribute value must be specified in the template parameter <code class="computeroutput">AttributeValueT</code>. Type sequences are not supported. </p></td></tr> 52</table></div> 53<p> 54</p> 55<div class="refsect2"> 56<a name="idm44984865857056"></a><h3> 57<a name="boost.log.sinks.basic_custom_mappingconstruct-copy-destruct"></a><code class="computeroutput">basic_custom_mapping</code> 58 public 59 construct/copy/destruct</h3> 60<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 61<pre class="literallayout"><span class="keyword">explicit</span> <a name="idm46079576945648-bb"></a><span class="identifier">basic_custom_mapping</span><span class="special">(</span><span class="identifier">attribute_name</span> <span class="keyword">const</span> <span class="special">&</span> name<span class="special">,</span> 62 <span class="identifier">mapped_type</span> <span class="keyword">const</span> <span class="special">&</span> default_value<span class="special">)</span><span class="special">;</span></pre> 63<p>Constructor</p> 64<p> 65</p> 66<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">Parameters:</span></p></td> 73<td><div class="variablelist"><table border="0" class="variablelist compact"> 74<colgroup> 75<col align="left" valign="top"> 76<col> 77</colgroup> 78<tbody> 79<tr> 80<td><p><span class="term"><code class="computeroutput">default_value</code></span></p></td> 81<td><p>The default native value that is returned if the conversion cannot be performed </p></td> 82</tr> 83<tr> 84<td><p><span class="term"><code class="computeroutput">name</code></span></p></td> 85<td><p>Attribute name </p></td> 86</tr> 87</tbody> 88</table></div></td> 89</tr></tbody> 90</table></div> 91</li></ol></div> 92</div> 93<div class="refsect2"> 94<a name="idm44984865840928"></a><h3> 95<a name="idm46079576953920-bb"></a><code class="computeroutput">basic_custom_mapping</code> public member functions</h3> 96<div class="orderedlist"><ol class="orderedlist" type="1"> 97<li class="listitem"> 98<pre class="literallayout"><span class="identifier">mapped_type</span> <a name="idm46079576953360-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">record_view</span> <span class="keyword">const</span> <span class="special">&</span> rec<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre> 99<p>Extraction operator. Extracts the attribute value and attempts to map it onto the native value.</p> 100<p> 101 102</p> 103<div class="variablelist"><table border="0" class="variablelist compact"> 104<colgroup> 105<col align="left" valign="top"> 106<col> 107</colgroup> 108<tbody> 109<tr> 110<td><p><span class="term">Parameters:</span></p></td> 111<td><div class="variablelist"><table border="0" class="variablelist compact"> 112<colgroup> 113<col align="left" valign="top"> 114<col> 115</colgroup> 116<tbody><tr> 117<td><p><span class="term"><code class="computeroutput">rec</code></span></p></td> 118<td><p>A log record to extract value from </p></td> 119</tr></tbody> 120</table></div></td> 121</tr> 122<tr> 123<td><p><span class="term">Returns:</span></p></td> 124<td><p>A mapped value, if mapping was successful, or the default value if mapping did not succeed. </p></td> 125</tr> 126</tbody> 127</table></div> 128</li> 129<li class="listitem"> 130<pre class="literallayout"><span class="identifier">implementation_defined</span> <a name="idm46079576949680-bb"></a><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span><span class="special">(</span><span class="identifier">attribute_value_type</span> <span class="keyword">const</span> <span class="special">&</span> key<span class="special">)</span><span class="special">;</span></pre> 131<p>Insertion operator</p> 132<p> 133 134</p> 135<div class="variablelist"><table border="0" class="variablelist compact"> 136<colgroup> 137<col align="left" valign="top"> 138<col> 139</colgroup> 140<tbody> 141<tr> 142<td><p><span class="term">Parameters:</span></p></td> 143<td><div class="variablelist"><table border="0" class="variablelist compact"> 144<colgroup> 145<col align="left" valign="top"> 146<col> 147</colgroup> 148<tbody><tr> 149<td><p><span class="term"><code class="computeroutput">key</code></span></p></td> 150<td><p>Attribute value to be mapped </p></td> 151</tr></tbody> 152</table></div></td> 153</tr> 154<tr> 155<td><p><span class="term">Returns:</span></p></td> 156<td><p>An object of unspecified type that allows to insert a new mapping through assignment. The <span class="emphasis"><em>key</em></span> argument becomes the key attribute value, and the assigned value becomes the mapped native value. </p></td> 157</tr> 158</tbody> 159</table></div> 160</li> 161</ol></div> 162</div> 163</div> 164</div> 165<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 166<td align="left"></td> 167<td align="right"><div class="copyright-footer">Copyright © 2007-2019 Andrey Semashev<p> 168 Distributed under the Boost Software License, Version 1.0. (See accompanying 169 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>). 170 </p> 171</div></td> 172</tr></table> 173<hr> 174<div class="spirit-nav"> 175<a accesskey="p" href="asynchronous_sink/scoped_thread_id.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../sinks.html#header.boost.log.sinks.attribute_mapping_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="basic_direct_mapping.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 176</div> 177</body> 178</html> 179
