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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="beast.ref.boost__beast__buffers_type"></a><a class="link" href="boost__beast__buffers_type.html" title="buffers_type">buffers_type</a>
  28 </h4></div></div></div>
  29 <p>
  30         <a class="indexterm" name="idm45873511495360"></a>
  31 Type alias for the underlying buffer type of a list of buffer
  32         sequence types.
  33       </p>
  34 <h5>
  35 <a name="beast.ref.boost__beast__buffers_type.h0"></a>
  36         <span class="phrase"><a name="beast.ref.boost__beast__buffers_type.synopsis"></a></span><a class="link" href="boost__beast__buffers_type.html#beast.ref.boost__beast__buffers_type.synopsis">Synopsis</a>
  37       </h5>
  38 <p>
  39         Defined in header <code class="literal">&lt;<a href="../../../../../../boost/beast/core/buffer_traits.hpp" target="_top">boost/beast/core/buffer_traits.hpp</a>&gt;</code>
  40       </p>
  41 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  42     <span class="keyword">class</span><span class="special">...</span> <a class="link" href="../concepts/BufferSequence.html" title="BufferSequence"><span class="emphasis"><em>BufferSequence</em></span></a><span class="special">&gt;</span>
  43 <span class="keyword">using</span> <span class="identifier">buffers_type</span> <span class="special">=</span> <span class="emphasis"><em>see-below</em></span><span class="special">;</span>
  44 </pre>
  45 <h5>
  46 <a name="beast.ref.boost__beast__buffers_type.h1"></a>
  47         <span class="phrase"><a name="beast.ref.boost__beast__buffers_type.description"></a></span><a class="link" href="boost__beast__buffers_type.html#beast.ref.boost__beast__buffers_type.description">Description</a>
  48       </h5>
  49 <p>
  50         This metafunction is used to determine the underlying buffer type for a list
  51         of buffer sequence. The equivalent type of the alias will vary depending
  52         on the template type argument:
  53       </p>
  54 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  55 <li class="listitem">
  56             If every type in the list is a <span class="emphasis"><em>MutableBufferSequence</em></span>,
  57             the resulting type alias will be <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">mutable_buffer</span></code>,
  58             otherwise
  59           </li>
  60 <li class="listitem">
  61             The resulting type alias will be <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">const_buffer</span></code>.
  62           </li>
  63 </ul></div>
  64 <h5>
  65 <a name="beast.ref.boost__beast__buffers_type.h2"></a>
  66         <span class="phrase"><a name="beast.ref.boost__beast__buffers_type.example"></a></span><a class="link" href="boost__beast__buffers_type.html#beast.ref.boost__beast__buffers_type.example">Example</a>
  67       </h5>
  68 <p>
  69         The following code returns the first buffer in a buffer sequence, or generates
  70         a compilation error if the argument is not a buffer sequence:
  71       </p>
  72 <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">BufferSequence</span><span class="special">&gt;</span>
  73 <span class="identifier">buffers_type</span> <span class="special">&lt;</span><span class="identifier">BufferSequence</span><span class="special">&gt;</span>
  74 <span class="identifier">buffers_front</span> <span class="special">(</span><span class="identifier">BufferSequence</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">buffers</span><span class="special">)</span>
  75 <span class="special">{</span>
  76     <span class="keyword">static_assert</span><span class="special">(</span>
  77         <span class="identifier">net</span><span class="special">::</span><span class="identifier">is_const_buffer_sequence</span><span class="special">&lt;</span><span class="identifier">BufferSequence</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">,</span>
  78         <span class="string">"BufferSequence type requirements not met"</span><span class="special">);</span>
  79     <span class="keyword">auto</span> <span class="keyword">const</span> <span class="identifier">first</span> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">buffer_sequence_begin</span> <span class="special">(</span><span class="identifier">buffers</span><span class="special">);</span>
  80     <span class="keyword">if</span> <span class="special">(</span><span class="identifier">first</span> <span class="special">==</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">buffer_sequence_end</span> <span class="special">(</span><span class="identifier">buffers</span><span class="special">))</span>
  81         <span class="keyword">return</span> <span class="special">{};</span>
  82     <span class="keyword">return</span> <span class="special">*</span><span class="identifier">first</span><span class="special">;</span>
  83 <span class="special">}</span>
  84 </pre>
  85 <h5>
  86 <a name="beast.ref.boost__beast__buffers_type.h3"></a>
  87         <span class="phrase"><a name="beast.ref.boost__beast__buffers_type.template_parameters"></a></span><a class="link" href="boost__beast__buffers_type.html#beast.ref.boost__beast__buffers_type.template_parameters">Template
  88         Parameters</a>
  89       </h5>
  90 <div class="informaltable"><table class="table">
  91 <colgroup>
  92 <col>
  93 <col>
  94 </colgroup>
  95 <thead><tr>
  96 <th>
  97                 <p>
  98                   Type
  99                 </p>
 100               </th>
 101 <th>
 102                 <p>
 103                   Description
 104                 </p>
 105               </th>
 106 </tr></thead>
 107 <tbody><tr>
 108 <td>
 109                 <p>
 110                   <code class="computeroutput"><span class="identifier">BufferSequence</span></code>
 111                 </p>
 112               </td>
 113 <td>
 114                 <p>
 115                   A list of zero or more types to check. If this list is empty, the
 116                   resulting type alias will be <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">mutable_buffer</span></code>.
 117                 </p>
 118               </td>
 119 </tr></tbody>
 120 </table></div>
 121 <p>
 122         Convenience header <code class="literal">&lt;<a href="../../../../../../boost/beast/core.hpp" target="_top">boost/beast/core.hpp</a>&gt;</code>
 123       </p>
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