1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>windows::basic_random_access_handle::async_write_some_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="../windows__basic_random_access_handle.html" title="windows::basic_random_access_handle"> 9<link rel="prev" href="async_read_some_at.html" title="windows::basic_random_access_handle::async_read_some_at"> 10<link rel="next" href="basic_random_access_handle.html" title="windows::basic_random_access_handle::basic_random_access_handle"> 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_some_at.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../windows__basic_random_access_handle.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="basic_random_access_handle.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.windows__basic_random_access_handle.async_write_some_at"></a><a class="link" href="async_write_some_at.html" title="windows::basic_random_access_handle::async_write_some_at">windows::basic_random_access_handle::async_write_some_at</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.windows__basic_random_access_handle.async_write_some_at"></a> 31Start 32 an asynchronous write at the specified offset. 33 </p> 34<pre class="programlisting">template< 35 typename <a class="link" href="../ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>, 36 typename <a class="link" href="../WriteHandler.html" title="Write handler requirements">WriteHandler</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_write_some_at( 38 uint64_t offset, 39 const ConstBufferSequence & buffers, 40 WriteHandler && handler = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>); 41</pre> 42<p> 43 This function is used to asynchronously write data to the random-access 44 handle. The function call always returns immediately. 45 </p> 46<h6> 47<a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.h0"></a> 48 <span class="phrase"><a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.parameters"></a></span><a class="link" href="async_write_some_at.html#boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.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">offset</span></dt> 54<dd><p> 55 The offset at which the data will be written. 56 </p></dd> 57<dt><span class="term">buffers</span></dt> 58<dd><p> 59 One or more data buffers to be written to the handle. Although the 60 buffers object may be copied as necessary, ownership of the underlying 61 memory blocks is retained by the caller, which must guarantee that 62 they remain valid until the handler is called. 63 </p></dd> 64<dt><span class="term">handler</span></dt> 65<dd> 66<p> 67 The handler to be called when the write operation completes. Copies 68 will be made of the handler as required. The function signature of 69 the handler must be: 70</p> 71<pre class="programlisting">void handler( 72 const boost::system::error_code& error, // Result of operation. 73 std::size_t bytes_transferred // Number of bytes written. 74); 75</pre> 76<p> 77 Regardless of whether the asynchronous operation completes immediately 78 or not, the handler will not be invoked from within this function. 79 On immediate completion, invocation of the handler will be performed 80 in a manner equivalent to using <a class="link" href="../post.html" title="post"><code class="computeroutput">post</code></a>. 81 </p> 82</dd> 83</dl> 84</div> 85<h6> 86<a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.h1"></a> 87 <span class="phrase"><a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.remarks"></a></span><a class="link" href="async_write_some_at.html#boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.remarks">Remarks</a> 88 </h6> 89<p> 90 The write operation may not transmit all of the data to the peer. Consider 91 using the <a class="link" href="../async_write_at.html" title="async_write_at"><code class="computeroutput">async_write_at</code></a> 92 function if you need to ensure that all data is written before the asynchronous 93 operation completes. 94 </p> 95<h6> 96<a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.h2"></a> 97 <span class="phrase"><a name="boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.example"></a></span><a class="link" href="async_write_some_at.html#boost_asio.reference.windows__basic_random_access_handle.async_write_some_at.example">Example</a> 98 </h6> 99<p> 100 To write a single data buffer use the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a> 101 function as follows: 102 </p> 103<pre class="programlisting">handle.async_write_some_at(42, boost::asio::buffer(data, size), handler); 104</pre> 105<p> 106 See the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a> 107 documentation for information on writing multiple buffers in one go, and 108 how to use it with arrays, boost::array or std::vector. 109 </p> 110</div> 111<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 112<td align="left"></td> 113<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 114 Kohlhoff<p> 115 Distributed under the Boost Software License, Version 1.0. (See accompanying 116 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>) 117 </p> 118</div></td> 119</tr></table> 120<hr> 121<div class="spirit-nav"> 122<a accesskey="p" href="async_read_some_at.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../windows__basic_random_access_handle.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="basic_random_access_handle.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 123</div> 124</body> 125</html> 126
