1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>async_read_at</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_read/overload8.html" title="async_read (8 of 8 overloads)"> 10<link rel="next" href="async_read_at/overload1.html" title="async_read_at (1 of 4 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_read/overload8.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_at/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_at"></a><a class="link" href="async_read_at.html" title="async_read_at">async_read_at</a> 28</h3></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.async_read_at"></a> 31The <code class="computeroutput">async_read_at</code> 32 function is a composed asynchronous operation that reads a certain amount 33 of data at the specified offset. 34 </p> 35<p> 36 Start an asynchronous operation to read a certain amount of data at the specified 37 offset. 38 </p> 39<pre class="programlisting">template< 40 typename <a class="link" href="AsyncRandomAccessReadDevice.html" title="Buffer-oriented asynchronous random-access read device requirements">AsyncRandomAccessReadDevice</a>, 41 typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 42 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>> 43<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_at/overload1.html" title="async_read_at (1 of 4 overloads)">async_read_at</a>( 44 AsyncRandomAccessReadDevice & d, 45 uint64_t offset, 46 const MutableBufferSequence & buffers, 47 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>); 48 <span class="emphasis"><em>» <a class="link" href="async_read_at/overload1.html" title="async_read_at (1 of 4 overloads)">more...</a></em></span> 49 50template< 51 typename <a class="link" href="AsyncRandomAccessReadDevice.html" title="Buffer-oriented asynchronous random-access read device requirements">AsyncRandomAccessReadDevice</a>, 52 typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 53 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 54 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>> 55<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_at/overload2.html" title="async_read_at (2 of 4 overloads)">async_read_at</a>( 56 AsyncRandomAccessReadDevice & d, 57 uint64_t offset, 58 const MutableBufferSequence & buffers, 59 CompletionCondition completion_condition, 60 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>); 61 <span class="emphasis"><em>» <a class="link" href="async_read_at/overload2.html" title="async_read_at (2 of 4 overloads)">more...</a></em></span> 62 63template< 64 typename <a class="link" href="AsyncRandomAccessReadDevice.html" title="Buffer-oriented asynchronous random-access read device requirements">AsyncRandomAccessReadDevice</a>, 65 typename Allocator, 66 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>> 67<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_at/overload3.html" title="async_read_at (3 of 4 overloads)">async_read_at</a>( 68 AsyncRandomAccessReadDevice & d, 69 uint64_t offset, 70 basic_streambuf< Allocator > & b, 71 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>); 72 <span class="emphasis"><em>» <a class="link" href="async_read_at/overload3.html" title="async_read_at (3 of 4 overloads)">more...</a></em></span> 73 74template< 75 typename <a class="link" href="AsyncRandomAccessReadDevice.html" title="Buffer-oriented asynchronous random-access read device requirements">AsyncRandomAccessReadDevice</a>, 76 typename Allocator, 77 typename <a class="link" href="CompletionCondition.html" title="Completion condition requirements">CompletionCondition</a>, 78 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>> 79<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_at/overload4.html" title="async_read_at (4 of 4 overloads)">async_read_at</a>( 80 AsyncRandomAccessReadDevice & d, 81 uint64_t offset, 82 basic_streambuf< Allocator > & b, 83 CompletionCondition completion_condition, 84 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>); 85 <span class="emphasis"><em>» <a class="link" href="async_read_at/overload4.html" title="async_read_at (4 of 4 overloads)">more...</a></em></span> 86</pre> 87<h5> 88<a name="boost_asio.reference.async_read_at.h0"></a> 89 <span class="phrase"><a name="boost_asio.reference.async_read_at.requirements"></a></span><a class="link" href="async_read_at.html#boost_asio.reference.async_read_at.requirements">Requirements</a> 90 </h5> 91<p> 92 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/read_at.hpp</code> 93 </p> 94<p> 95 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 96 </p> 97</div> 98<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 99<td align="left"></td> 100<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 101 Kohlhoff<p> 102 Distributed under the Boost Software License, Version 1.0. (See accompanying 103 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>) 104 </p> 105</div></td> 106</tr></table> 107<hr> 108<div class="spirit-nav"> 109<a accesskey="p" href="async_read/overload8.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_at/overload1.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 110</div> 111</body> 112</html> 113
