1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>ssl::stream::async_read_some</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="../ssl__stream.html" title="ssl::stream"> 9<link rel="prev" href="async_handshake/overload2.html" title="ssl::stream::async_handshake (2 of 2 overloads)"> 10<link rel="next" href="async_shutdown.html" title="ssl::stream::async_shutdown"> 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="async_handshake/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../ssl__stream.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_shutdown.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_asio.reference.ssl__stream.async_read_some"></a><a class="link" href="async_read_some.html" title="ssl::stream::async_read_some">ssl::stream::async_read_some</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.ssl__stream.async_read_some"></a> 31Start 32 an asynchronous read. 33 </p> 34<pre class="programlisting">template< 35 typename <a class="link" href="../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 36 typename <a class="link" href="../ReadHandler.html" title="Read handler requirements">ReadHandler</a> = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>> 37<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_read_some( 38 const MutableBufferSequence & buffers, 39 ReadHandler && handler = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>); 40</pre> 41<p> 42 This function is used to asynchronously read one or more bytes of data 43 from the stream. The function call always returns immediately. 44 </p> 45<h6> 46<a name="boost_asio.reference.ssl__stream.async_read_some.h0"></a> 47 <span class="phrase"><a name="boost_asio.reference.ssl__stream.async_read_some.parameters"></a></span><a class="link" href="async_read_some.html#boost_asio.reference.ssl__stream.async_read_some.parameters">Parameters</a> 48 </h6> 49<div class="variablelist"> 50<p class="title"><b></b></p> 51<dl class="variablelist"> 52<dt><span class="term">buffers</span></dt> 53<dd><p> 54 The buffers into which the data will be read. Although the buffers 55 object may be copied as necessary, ownership of the underlying buffers 56 is retained by the caller, which must guarantee that they remain 57 valid until the handler is called. 58 </p></dd> 59<dt><span class="term">handler</span></dt> 60<dd> 61<p> 62 The handler to be called when the read operation completes. Copies 63 will be made of the handler as required. The equivalent function 64 signature of the handler must be: 65</p> 66<pre class="programlisting">void handler( 67 const boost::system::error_code& error, // Result of operation. 68 std::size_t bytes_transferred // Number of bytes read. 69); 70</pre> 71<p> 72 </p> 73</dd> 74</dl> 75</div> 76<h6> 77<a name="boost_asio.reference.ssl__stream.async_read_some.h1"></a> 78 <span class="phrase"><a name="boost_asio.reference.ssl__stream.async_read_some.remarks"></a></span><a class="link" href="async_read_some.html#boost_asio.reference.ssl__stream.async_read_some.remarks">Remarks</a> 79 </h6> 80<p> 81 The async_read_some operation may not read all of the requested number 82 of bytes. Consider using the <a class="link" href="../async_read.html" title="async_read"><code class="computeroutput">async_read</code></a> 83 function if you need to ensure that the requested amount of data is read 84 before the asynchronous operation completes. 85 </p> 86</div> 87<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 88<td align="left"></td> 89<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 90 Kohlhoff<p> 91 Distributed under the Boost Software License, Version 1.0. (See accompanying 92 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>) 93 </p> 94</div></td> 95</tr></table> 96<hr> 97<div class="spirit-nav"> 98<a accesskey="p" href="async_handshake/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../ssl__stream.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_shutdown.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 99</div> 100</body> 101</html> 102
