1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>read (9 of 16 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="../read.html" title="read"> 9<link rel="prev" href="overload8.html" title="read (8 of 16 overloads)"> 10<link rel="next" href="overload10.html" title="read (10 of 16 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="overload8.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../read.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="overload10.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.read.overload9"></a><a class="link" href="overload9.html" title="read (9 of 16 overloads)">read (9 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< 34 typename <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a>, 35 typename Allocator> 36std::size_t read( 37 SyncReadStream & s, 38 basic_streambuf< Allocator > & b); 39</pre> 40<p> 41 This function is used to read a certain number of bytes of data from a 42 stream. The call will block until one of the following conditions is true: 43 </p> 44<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 45<li class="listitem"> 46 The supplied buffer is full (that is, it has reached maximum size). 47 </li> 48<li class="listitem"> 49 An error occurred. 50 </li> 51</ul></div> 52<p> 53 This operation is implemented in terms of zero or more calls to the stream's 54 read_some function. 55 </p> 56<h6> 57<a name="boost_asio.reference.read.overload9.h0"></a> 58 <span class="phrase"><a name="boost_asio.reference.read.overload9.parameters"></a></span><a class="link" href="overload9.html#boost_asio.reference.read.overload9.parameters">Parameters</a> 59 </h6> 60<div class="variablelist"> 61<p class="title"><b></b></p> 62<dl class="variablelist"> 63<dt><span class="term">s</span></dt> 64<dd><p> 65 The stream from which the data is to be read. The type must support 66 the SyncReadStream concept. 67 </p></dd> 68<dt><span class="term">b</span></dt> 69<dd><p> 70 The <a class="link" href="../basic_streambuf.html" title="basic_streambuf"><code class="computeroutput">basic_streambuf</code></a> 71 object into which the data will be read. 72 </p></dd> 73</dl> 74</div> 75<h6> 76<a name="boost_asio.reference.read.overload9.h1"></a> 77 <span class="phrase"><a name="boost_asio.reference.read.overload9.return_value"></a></span><a class="link" href="overload9.html#boost_asio.reference.read.overload9.return_value">Return 78 Value</a> 79 </h6> 80<p> 81 The number of bytes transferred. 82 </p> 83<h6> 84<a name="boost_asio.reference.read.overload9.h2"></a> 85 <span class="phrase"><a name="boost_asio.reference.read.overload9.exceptions"></a></span><a class="link" href="overload9.html#boost_asio.reference.read.overload9.exceptions">Exceptions</a> 86 </h6> 87<div class="variablelist"> 88<p class="title"><b></b></p> 89<dl class="variablelist"> 90<dt><span class="term">boost::system::system_error</span></dt> 91<dd><p> 92 Thrown on failure. 93 </p></dd> 94</dl> 95</div> 96<h6> 97<a name="boost_asio.reference.read.overload9.h3"></a> 98 <span class="phrase"><a name="boost_asio.reference.read.overload9.remarks"></a></span><a class="link" href="overload9.html#boost_asio.reference.read.overload9.remarks">Remarks</a> 99 </h6> 100<p> 101 This overload is equivalent to calling: 102 </p> 103<pre class="programlisting">boost::asio::read( 104 s, b, 105 boost::asio::transfer_all()); 106</pre> 107</div> 108<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 109<td align="left"></td> 110<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 111 Kohlhoff<p> 112 Distributed under the Boost Software License, Version 1.0. (See accompanying 113 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>) 114 </p> 115</div></td> 116</tr></table> 117<hr> 118<div class="spirit-nav"> 119<a accesskey="p" href="overload8.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../read.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="overload10.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 120</div> 121</body> 122</html> 123
