doc/html/boost_asio/reference/basic_datagram_socket/async_receive_from/overload2.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>basic_datagram_socket::async_receive_from (2 of 2 overloads)</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="../../../../boost_asio.html" title="Boost.Asio">
   8 <link rel="up" href="../async_receive_from.html" title="basic_datagram_socket::async_receive_from">
   9 <link rel="prev" href="overload1.html" title="basic_datagram_socket::async_receive_from (1 of 2 overloads)">
  10 <link rel="next" href="../async_send.html" title="basic_datagram_socket::async_send">
  11 </head>
  12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13 <table cellpadding="2" width="100%"><tr>
  14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
  15 <td align="center"><a href="../../../../../../index.html">Home</a></td>
  16 <td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
  17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
  18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
  19 <td align="center"><a href="../../../../../../more/index.htm">More</a></td>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="overload1.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_receive_from.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../boost_asio.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../async_send.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h5 class="title">
  27 <a name="boost_asio.reference.basic_datagram_socket.async_receive_from.overload2"></a><a class="link" href="overload2.html" title="basic_datagram_socket::async_receive_from (2 of 2 overloads)">basic_datagram_socket::async_receive_from
  28           (2 of 2 overloads)</a>
  29 </h5></div></div></div>
  30 <p>
  31             Start an asynchronous receive.
  32           </p>
  33 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  34     <span class="keyword">typename</span> <a class="link" href="../../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a><span class="special">,</span>
  35     <span class="keyword">typename</span> <a class="link" href="../../ReadHandler.html" title="Read handler requirements">ReadHandler</a><span class="special">&gt;</span>
  36 <a class="link" href="../../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.return_type_of_an_initiating_function"><span class="emphasis"><em>void-or-deduced</em></span></a> <span class="identifier">async_receive_from</span><span class="special">(</span>
  37     <span class="keyword">const</span> <span class="identifier">MutableBufferSequence</span> <span class="special">&amp;</span> <span class="identifier">buffers</span><span class="special">,</span>
  38     <span class="identifier">endpoint_type</span> <span class="special">&amp;</span> <span class="identifier">sender_endpoint</span><span class="special">,</span>
  39     <span class="identifier">socket_base</span><span class="special">::</span><span class="identifier">message_flags</span> <span class="identifier">flags</span><span class="special">,</span>
  40     <span class="identifier">ReadHandler</span> <span class="identifier">handler</span><span class="special">);</span>
  41 </pre>
  42 <p>
  43             This function is used to asynchronously receive a datagram. The function
  44             call always returns immediately.
  45           </p>
  46 <h6>
  47 <a name="boost_asio.reference.basic_datagram_socket.async_receive_from.overload2.h0"></a>
  48             <span class="phrase"><a name="boost_asio.reference.basic_datagram_socket.async_receive_from.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.basic_datagram_socket.async_receive_from.overload2.parameters">Parameters</a>
  49           </h6>
  50 <div class="variablelist">
  51 <p class="title"><b></b></p>
  52 <dl class="variablelist">
  53 <dt><span class="term">buffers</span></dt>
  54 <dd><p>
  55                   One or more buffers into which the data will be received. Although
  56                   the buffers object may be copied as necessary, ownership of the
  57                   underlying memory blocks is retained by the caller, which must
  58                   guarantee that they remain valid until the handler is called.
  59                 </p></dd>
  60 <dt><span class="term">sender_endpoint</span></dt>
  61 <dd><p>
  62                   An endpoint object that receives the endpoint of the remote sender
  63                   of the datagram. Ownership of the sender_endpoint object is retained
  64                   by the caller, which must guarantee that it is valid until the
  65                   handler is called.
  66                 </p></dd>
  67 <dt><span class="term">flags</span></dt>
  68 <dd><p>
  69                   Flags specifying how the receive call is to be made.
  70                 </p></dd>
  71 <dt><span class="term">handler</span></dt>
  72 <dd>
  73 <p>
  74                   The handler to be called when the receive operation completes.
  75                   Copies will be made of the handler as required. The function signature
  76                   of the handler must be:
  77 </p>
  78 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span>
  79   <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">error</span><span class="special">,</span> <span class="comment">// Result of operation.</span>
  80   <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">bytes_transferred</span>           <span class="comment">// Number of bytes received.</span>
  81 <span class="special">);</span>
  82 </pre>
  83 <p>
  84                   Regardless of whether the asynchronous operation completes immediately
  85                   or not, the handler will not be invoked from within this function.
  86                   Invocation of the handler will be performed in a manner equivalent
  87                   to using <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">post</span><span class="special">()</span></code>.
  88                 </p>
  89 </dd>
  90 </dl>
  91 </div>
  92 </div>
  93 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  94 <td align="left"></td>
  95 <td align="right"><div class="copyright-footer">Copyright &#169; 2003-2017 Christopher M. Kohlhoff<p>
  96         Distributed under the Boost Software License, Version 1.0. (See accompanying
  97         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>)
  98       </p>
  99 </div></td>
 100 </tr></table>
 101 <hr>
 102 <div class="spirit-nav">
 103 <a accesskey="p" href="overload1.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_receive_from.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../boost_asio.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../async_send.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 104 </div>
 105 </body>
 106 </html>