1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>async_read</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="../reference.html" title="Reference"> 9<link rel="prev" href="async_initiate.html" title="async_initiate"> 10<link rel="next" href="async_read/overload1.html" title="async_read (1 of 8 overloads)"> 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_initiate.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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_read/overload1.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="boost_asio.reference.async_read"></a><a class="link" href="async_read.html" title="async_read">async_read</a> 28</h3></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.async_read"></a> 31The <code class="computeroutput">async_read</code> function 32 is a composed asynchronous operation that reads a certain amount of data 33 from a stream before completion. 34 </p> 35<p> 36 Start an asynchronous operation to read a certain amount of data from a stream. 37 </p> 38<pre class="programlisting">template< 39 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 40 typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 41 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>> 42<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> <a class="link" href="async_read/overload1.html" title="async_read (1 of 8 overloads)">async_read</a>( 43 AsyncReadStream & s, 44 const MutableBufferSequence & buffers, 45 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>, 46 typename enable_if< is_mutable_buffer_sequence< MutableBufferSequence >::value >::type * = 0); 47 <span class="emphasis"><em>» <a class="link" href="async_read/overload1.html" title="async_read (1 of 8 overloads)">more...</a></em></span> 48 49template< 50 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 51 typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 52 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 53 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>> 54<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> <a class="link" href="async_read/overload2.html" title="async_read (2 of 8 overloads)">async_read</a>( 55 AsyncReadStream & s, 56 const MutableBufferSequence & buffers, 57 CompletionCondition completion_condition, 58 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>, 59 typename enable_if< is_mutable_buffer_sequence< MutableBufferSequence >::value >::type * = 0); 60 <span class="emphasis"><em>» <a class="link" href="async_read/overload2.html" title="async_read (2 of 8 overloads)">more...</a></em></span> 61 62template< 63 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 64 typename <a class="link" href="DynamicBuffer_v1.html" title="Dynamic buffer requirements (version 1)">DynamicBuffer_v1</a>, 65 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>> 66<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> <a class="link" href="async_read/overload3.html" title="async_read (3 of 8 overloads)">async_read</a>( 67 AsyncReadStream & s, 68 DynamicBuffer_v1 && buffers, 69 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>, 70 typename enable_if< is_dynamic_buffer_v1< typename decay< DynamicBuffer_v1 >::type >::value &&!is_dynamic_buffer_v2< typename decay< DynamicBuffer_v1 >::type >::value >::type * = 0); 71 <span class="emphasis"><em>» <a class="link" href="async_read/overload3.html" title="async_read (3 of 8 overloads)">more...</a></em></span> 72 73template< 74 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 75 typename <a class="link" href="DynamicBuffer_v1.html" title="Dynamic buffer requirements (version 1)">DynamicBuffer_v1</a>, 76 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 77 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>> 78<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> <a class="link" href="async_read/overload4.html" title="async_read (4 of 8 overloads)">async_read</a>( 79 AsyncReadStream & s, 80 DynamicBuffer_v1 && buffers, 81 CompletionCondition completion_condition, 82 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>, 83 typename enable_if< is_dynamic_buffer_v1< typename decay< DynamicBuffer_v1 >::type >::value &&!is_dynamic_buffer_v2< typename decay< DynamicBuffer_v1 >::type >::value >::type * = 0); 84 <span class="emphasis"><em>» <a class="link" href="async_read/overload4.html" title="async_read (4 of 8 overloads)">more...</a></em></span> 85 86template< 87 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 88 typename Allocator, 89 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>> 90<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> <a class="link" href="async_read/overload5.html" title="async_read (5 of 8 overloads)">async_read</a>( 91 AsyncReadStream & s, 92 basic_streambuf< Allocator > & b, 93 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>); 94 <span class="emphasis"><em>» <a class="link" href="async_read/overload5.html" title="async_read (5 of 8 overloads)">more...</a></em></span> 95 96template< 97 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 98 typename Allocator, 99 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 100 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>> 101<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> <a class="link" href="async_read/overload6.html" title="async_read (6 of 8 overloads)">async_read</a>( 102 AsyncReadStream & s, 103 basic_streambuf< Allocator > & b, 104 CompletionCondition completion_condition, 105 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>); 106 <span class="emphasis"><em>» <a class="link" href="async_read/overload6.html" title="async_read (6 of 8 overloads)">more...</a></em></span> 107 108template< 109 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 110 typename <a class="link" href="DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">DynamicBuffer_v2</a>, 111 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>> 112<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> <a class="link" href="async_read/overload7.html" title="async_read (7 of 8 overloads)">async_read</a>( 113 AsyncReadStream & s, 114 DynamicBuffer_v2 buffers, 115 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>, 116 typename enable_if< is_dynamic_buffer_v2< DynamicBuffer_v2 >::value >::type * = 0); 117 <span class="emphasis"><em>» <a class="link" href="async_read/overload7.html" title="async_read (7 of 8 overloads)">more...</a></em></span> 118 119template< 120 typename <a class="link" href="AsyncReadStream.html" title="Buffer-oriented asynchronous read stream requirements">AsyncReadStream</a>, 121 typename <a class="link" href="DynamicBuffer_v2.html" title="Dynamic buffer requirements (version 2)">DynamicBuffer_v2</a>, 122 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 123 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>> 124<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> <a class="link" href="async_read/overload8.html" title="async_read (8 of 8 overloads)">async_read</a>( 125 AsyncReadStream & s, 126 DynamicBuffer_v2 buffers, 127 CompletionCondition completion_condition, 128 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>, 129 typename enable_if< is_dynamic_buffer_v2< DynamicBuffer_v2 >::value >::type * = 0); 130 <span class="emphasis"><em>» <a class="link" href="async_read/overload8.html" title="async_read (8 of 8 overloads)">more...</a></em></span> 131</pre> 132<h5> 133<a name="boost_asio.reference.async_read.h0"></a> 134 <span class="phrase"><a name="boost_asio.reference.async_read.requirements"></a></span><a class="link" href="async_read.html#boost_asio.reference.async_read.requirements">Requirements</a> 135 </h5> 136<p> 137 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/read.hpp</code> 138 </p> 139<p> 140 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 141 </p> 142</div> 143<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 144<td align="left"></td> 145<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 146 Kohlhoff<p> 147 Distributed under the Boost Software License, Version 1.0. (See accompanying 148 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>) 149 </p> 150</div></td> 151</tr></table> 152<hr> 153<div class="spirit-nav"> 154<a accesskey="p" href="async_initiate.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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_read/overload1.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 155</div> 156</body> 157</html> 158
