doc/html/boost_asio/reference/read/overload1.html

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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="boost_asio.reference.read.overload1"></a><a class="link" href="overload1.html" title="read (1 of 16 overloads)">read (1 of 16
  28         overloads)</a>
  29 </h4></div></div></div>
  30 <p>
  31           Attempt to read a certain amount of data from a stream before returning.
  32         </p>
  33 <pre class="programlisting">template&lt;
  34     typename <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a>,
  35     typename <a class="link" href="../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>&gt;
  36 std::size_t read(
  37     SyncReadStream &amp; s,
  38     const MutableBufferSequence &amp; buffers,
  39     typename enable_if&lt; is_mutable_buffer_sequence&lt; MutableBufferSequence &gt;::value &gt;::type *  = 0);
  40 </pre>
  41 <p>
  42           This function is used to read a certain number of bytes of data from a
  43           stream. The call will block until one of the following conditions is true:
  44         </p>
  45 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  46 <li class="listitem">
  47               The supplied buffers are full. That is, the bytes transferred is equal
  48               to the sum of the buffer sizes.
  49             </li>
  50 <li class="listitem">
  51               An error occurred.
  52             </li>
  53 </ul></div>
  54 <p>
  55           This operation is implemented in terms of zero or more calls to the stream's
  56           read_some function.
  57         </p>
  58 <h6>
  59 <a name="boost_asio.reference.read.overload1.h0"></a>
  60           <span class="phrase"><a name="boost_asio.reference.read.overload1.parameters"></a></span><a class="link" href="overload1.html#boost_asio.reference.read.overload1.parameters">Parameters</a>
  61         </h6>
  62 <div class="variablelist">
  63 <p class="title"><b></b></p>
  64 <dl class="variablelist">
  65 <dt><span class="term">s</span></dt>
  66 <dd><p>
  67                 The stream from which the data is to be read. The type must support
  68                 the SyncReadStream concept.
  69               </p></dd>
  70 <dt><span class="term">buffers</span></dt>
  71 <dd><p>
  72                 One or more buffers into which the data will be read. The sum of
  73                 the buffer sizes indicates the maximum number of bytes to read from
  74                 the stream.
  75               </p></dd>
  76 </dl>
  77 </div>
  78 <h6>
  79 <a name="boost_asio.reference.read.overload1.h1"></a>
  80           <span class="phrase"><a name="boost_asio.reference.read.overload1.return_value"></a></span><a class="link" href="overload1.html#boost_asio.reference.read.overload1.return_value">Return
  81           Value</a>
  82         </h6>
  83 <p>
  84           The number of bytes transferred.
  85         </p>
  86 <h6>
  87 <a name="boost_asio.reference.read.overload1.h2"></a>
  88           <span class="phrase"><a name="boost_asio.reference.read.overload1.exceptions"></a></span><a class="link" href="overload1.html#boost_asio.reference.read.overload1.exceptions">Exceptions</a>
  89         </h6>
  90 <div class="variablelist">
  91 <p class="title"><b></b></p>
  92 <dl class="variablelist">
  93 <dt><span class="term">boost::system::system_error</span></dt>
  94 <dd><p>
  95                 Thrown on failure.
  96               </p></dd>
  97 </dl>
  98 </div>
  99 <h6>
 100 <a name="boost_asio.reference.read.overload1.h3"></a>
 101           <span class="phrase"><a name="boost_asio.reference.read.overload1.example"></a></span><a class="link" href="overload1.html#boost_asio.reference.read.overload1.example">Example</a>
 102         </h6>
 103 <p>
 104           To read into a single data buffer use the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a>
 105           function as follows:
 106         </p>
 107 <pre class="programlisting">boost::asio::read(s, boost::asio::buffer(data, size));
 108 </pre>
 109 <p>
 110           See the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a>
 111           documentation for information on reading into multiple buffers in one go,
 112           and how to use it with arrays, boost::array or std::vector.
 113         </p>
 114 <h6>
 115 <a name="boost_asio.reference.read.overload1.h4"></a>
 116           <span class="phrase"><a name="boost_asio.reference.read.overload1.remarks"></a></span><a class="link" href="overload1.html#boost_asio.reference.read.overload1.remarks">Remarks</a>
 117         </h6>
 118 <p>
 119           This overload is equivalent to calling:
 120         </p>
 121 <pre class="programlisting">boost::asio::read(
 122     s, buffers,
 123     boost::asio::transfer_all());
 124 </pre>
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