libs/log/doc/html/boost/log/attributes/constant.html

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   4 <title>Class template constant</title>
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  18 <div class="refentry">
  19 <a name="boost.log.attributes.constant"></a><div class="titlepage"></div>
  20 <div class="refnamediv">
  21 <h2><span class="refentrytitle">Class template constant</span></h2>
  22 <p>boost::log::attributes::constant &#8212; A class of an attribute that holds a single constant value. </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: &lt;<a class="link" href="../../../attributes.html#header.boost.log.attributes.constant_hpp" title="Header &lt;boost/log/attributes/constant.hpp&gt;">boost/log/attributes/constant.hpp</a>&gt;
  26
  27 </span><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span>
  28 <span class="keyword">class</span> <a class="link" href="constant.html" title="Class template constant">constant</a> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">attribute</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.constant.value_type"></a><span class="identifier">value_type</span><span class="special">;</span>  <span class="comment">// Attribute value type. </span>
  32
  33   <span class="comment">// member classes/structs/unions</span>
  34
  35   <span class="comment">// Factory implementation.</span>
  36
  37   <span class="keyword">class</span> <a class="link" href="constant/impl.html" title="Class impl">impl</a> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">attribute_value_impl</span><span class="special">&lt;</span> <span class="identifier">value_type</span> <span class="special">&gt;</span> <span class="special">{</span>
  38   <span class="keyword">public</span><span class="special">:</span>
  39     <span class="comment">// <a class="link" href="constant/impl.html#boost.log.attributes.constant.implconstruct-copy-destruct">construct/copy/destruct</a></span>
  40     <span class="keyword">explicit</span> <a class="link" href="constant/impl.html#idp61917440-bb"><span class="identifier">impl</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  41     <span class="keyword">explicit</span> <a class="link" href="constant/impl.html#idp61919136-bb"><span class="identifier">impl</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="special">&amp;&amp;</span><span class="special">)</span><span class="special">;</span>
  42   <span class="special">}</span><span class="special">;</span>
  43
  44   <span class="comment">// <a class="link" href="constant.html#boost.log.attributes.constantconstruct-copy-destruct">construct/copy/destruct</a></span>
  45   <span class="keyword">explicit</span> <a class="link" href="constant.html#idp61924656-bb"><span class="identifier">constant</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  46   <span class="keyword">explicit</span> <a class="link" href="constant.html#idp61926352-bb"><span class="identifier">constant</span></a><span class="special">(</span><span class="identifier">value_type</span> <span class="special">&amp;&amp;</span><span class="special">)</span><span class="special">;</span>
  47   <span class="keyword">explicit</span> <a class="link" href="constant.html#idp61928048-bb"><span class="identifier">constant</span></a><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</span> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  48
  49   <span class="comment">// <a class="link" href="constant.html#idp61921968-bb">public member functions</a></span>
  50   <span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span> <a class="link" href="constant.html#idp61922528-bb"><span class="identifier">get</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  51 <span class="special">}</span><span class="special">;</span></pre></div>
  52 <div class="refsect1">
  53 <a name="idp106208992"></a><h2>Description</h2>
  54 <p>The constant is a simplest and one of the most frequently used types of attributes. It stores a constant value, which it eventually returns as its value each time requested. </p>
  55 <div class="refsect2">
  56 <a name="idp106209856"></a><h3>
  57 <a name="boost.log.attributes.constantconstruct-copy-destruct"></a><code class="computeroutput">constant</code>
  58         public
  59        construct/copy/destruct</h3>
  60 <div class="orderedlist"><ol class="orderedlist" type="1">
  61 <li class="listitem">
  62 <pre class="literallayout"><span class="keyword">explicit</span> <a name="idp61924656-bb"></a><span class="identifier">constant</span><span class="special">(</span><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span> value<span class="special">)</span><span class="special">;</span></pre>
  63 <p>Constructor with the stored value initialization </p>
  64 </li>
  65 <li class="listitem">
  66 <pre class="literallayout"><span class="keyword">explicit</span> <a name="idp61926352-bb"></a><span class="identifier">constant</span><span class="special">(</span><span class="identifier">value_type</span> <span class="special">&amp;&amp;</span> value<span class="special">)</span><span class="special">;</span></pre>
  67 <p>Constructor with the stored value initialization </p>
  68 </li>
  69 <li class="listitem">
  70 <pre class="literallayout"><span class="keyword">explicit</span> <a name="idp61928048-bb"></a><span class="identifier">constant</span><span class="special">(</span><a class="link" href="cast_source.html" title="Class cast_source">cast_source</a> <span class="keyword">const</span> <span class="special">&amp;</span> source<span class="special">)</span><span class="special">;</span></pre>
  71 <p>Constructor for casting support </p>
  72 </li>
  73 </ol></div>
  74 </div>
  75 <div class="refsect2">
  76 <a name="idp106231808"></a><h3>
  77 <a name="idp61921968-bb"></a><code class="computeroutput">constant</code> public member functions</h3>
  78 <div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
  79 <pre class="literallayout"><span class="identifier">value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span> <a name="idp61922528-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>
  80 <p>
  81 </p>
  82 <div class="variablelist"><table border="0" class="variablelist compact">
  83 <colgroup>
  84 <col align="left" valign="top">
  85 <col>
  86 </colgroup>
  87 <tbody><tr>
  88 <td><p><span class="term">Returns:</span></p></td>
  89 <td><p>Reference to the contained value. </p></td>
  90 </tr></tbody>
  91 </table></div>
  92 </li></ol></div>
  93 </div>
  94 </div>
  95 </div>
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  98 <td align="right"><div class="copyright-footer">Copyright &#169; 2007-2016 Andrey Semashev<p>
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