1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>transfer_at_least</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="transfer_all.html" title="transfer_all"> 10<link rel="next" href="transfer_exactly.html" title="transfer_exactly"> 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="transfer_all.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="transfer_exactly.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.transfer_at_least"></a><a class="link" href="transfer_at_least.html" title="transfer_at_least">transfer_at_least</a> 28</h3></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.transfer_at_least"></a> 31Return a completion 32 condition function object that indicates that a read or write operation should 33 continue until a minimum number of bytes has been transferred, or until an 34 error occurs. 35 </p> 36<pre class="programlisting">unspecified transfer_at_least( 37 std::size_t minimum); 38</pre> 39<p> 40 This function is used to create an object, of unspecified type, that meets 41 CompletionCondition requirements. 42 </p> 43<h5> 44<a name="boost_asio.reference.transfer_at_least.h0"></a> 45 <span class="phrase"><a name="boost_asio.reference.transfer_at_least.example"></a></span><a class="link" href="transfer_at_least.html#boost_asio.reference.transfer_at_least.example">Example</a> 46 </h5> 47<p> 48 Reading until a buffer is full or contains at least 64 bytes: 49 </p> 50<pre class="programlisting">boost::array<char, 128> buf; 51boost::system::error_code ec; 52std::size_t n = boost::asio::read( 53 sock, boost::asio::buffer(buf), 54 boost::asio::transfer_at_least(64), ec); 55if (ec) 56{ 57 // An error occurred. 58} 59else 60{ 61 // n >= 64 && n <= 128 62} 63</pre> 64<h5> 65<a name="boost_asio.reference.transfer_at_least.h1"></a> 66 <span class="phrase"><a name="boost_asio.reference.transfer_at_least.requirements"></a></span><a class="link" href="transfer_at_least.html#boost_asio.reference.transfer_at_least.requirements">Requirements</a> 67 </h5> 68<p> 69 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/completion_condition.hpp</code> 70 </p> 71<p> 72 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 73 </p> 74</div> 75<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 76<td align="left"></td> 77<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 78 Kohlhoff<p> 79 Distributed under the Boost Software License, Version 1.0. (See accompanying 80 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>) 81 </p> 82</div></td> 83</tr></table> 84<hr> 85<div class="spirit-nav"> 86<a accesskey="p" href="transfer_all.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="transfer_exactly.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 87</div> 88</body> 89</html> 90
