tri11paragon
/
Insane_DNS
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
Insane_DNS/libraries/asio-1.28.1/doc/asio/overview/cpp2011/move_objects.html

100 lines
8.2 KiB
HTML
Raw Normal View History

can extract domain names
2023-10-24 21:59:30 -04:00
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Movable I/O Objects</title>
<link rel="stylesheet" href="../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../index.html" title="Asio">
<link rel="up" href="../cpp2011.html" title="C++ 2011 Support">
<link rel="prev" href="system_error.html" title="System Errors and Error Codes">
<link rel="next" href="move_handlers.html" title="Movable Handlers">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="system_error.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../cpp2011.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="move_handlers.html"><img src="../../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="asio.overview.cpp2011.move_objects"></a><a class="link" href="move_objects.html" title="Movable I/O Objects">Movable I/O Objects</a>
</h4></div></div></div>
<p>
When move support is available (via rvalue references), Asio allows move
construction and assignment of sockets, serial ports, POSIX descriptors
and Windows handles.
</p>
<p>
Move support allows you to write code like:
</p>
<pre class="programlisting"><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span> <span class="identifier">make_socket</span><span class="special">(</span><span class="identifier">io_context</span><span class="special">&amp;</span> <span class="identifier">i</span><span class="special">)</span>
<span class="special">{</span>
<span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span> <span class="identifier">s</span><span class="special">(</span><span class="identifier">i</span><span class="special">);</span>
<span class="special">...</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
or:
</p>
<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">connection</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">enable_shared_from_this</span><span class="special">&lt;</span><span class="identifier">connection</span><span class="special">&gt;</span>
<span class="special">{</span>
<span class="keyword">private</span><span class="special">:</span>
<span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span> <span class="identifier">socket_</span><span class="special">;</span>
<span class="special">...</span>
<span class="keyword">public</span><span class="special">:</span>
<span class="identifier">connection</span><span class="special">(</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span><span class="special">&amp;&amp;</span> <span class="identifier">s</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">socket_</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">s</span><span class="special">))</span> <span class="special">{}</span>
<span class="special">...</span>
<span class="special">};</span>
<span class="special">...</span>
<span class="keyword">class</span> <span class="identifier">server</span>
<span class="special">{</span>
<span class="keyword">private</span><span class="special">:</span>
<span class="identifier">tcp</span><span class="special">::</span><span class="identifier">acceptor</span> <span class="identifier">acceptor_</span><span class="special">;</span>
<span class="special">...</span>
<span class="keyword">void</span> <span class="identifier">handle_accept</span><span class="special">(</span><span class="identifier">error_code</span> <span class="identifier">ec</span><span class="special">,</span> <span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span> <span class="identifier">socket</span><span class="special">)</span>
<span class="special">{</span>
<span class="keyword">if</span> <span class="special">(!</span><span class="identifier">ec</span><span class="special">)</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">make_shared</span><span class="special">&lt;</span><span class="identifier">connection</span><span class="special">&gt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">socket</span><span class="special">))-&gt;</span><span class="identifier">go</span><span class="special">();</span>
<span class="identifier">acceptor_</span><span class="special">.</span><span class="identifier">async_accept</span><span class="special">(...);</span>
<span class="special">}</span>
<span class="special">...</span>
<span class="special">};</span>
</pre>
<p>
as well as:
</p>
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span><span class="special">&gt;</span> <span class="identifier">sockets</span><span class="special">;</span>
<span class="identifier">sockets</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">socket</span><span class="special">(...));</span>
</pre>
<p>
A word of warning: There is nothing stopping you from moving these objects
while there are pending asynchronous operations, but it is unlikely to
be a good idea to do so. In particular, composed operations like <a class="link" href="../../reference/async_read.html" title="async_read">async_read()</a> store a reference
to the stream object. Moving during the composed operation means that the
composed operation may attempt to access a moved-from object.
</p>
<p>
Move support is automatically enabled for <code class="literal">g++</code> 4.5 and
later, when the <code class="literal">-std=c++0x</code> or <code class="literal">-std=gnu++0x</code>
compiler options are used. It may be disabled by defining <code class="computeroutput"><span class="identifier">ASIO_DISABLE_MOVE</span></code>, or explicitly enabled
for other compilers by defining <code class="computeroutput"><span class="identifier">ASIO_HAS_MOVE</span></code>.
Note that these macros also affect the availability of <a class="link" href="move_handlers.html" title="Movable Handlers">movable
handlers</a>.
</p>
</div>
<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
</div>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="system_error.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../cpp2011.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="move_handlers.html"><img src="../../../next.png" alt="Next"></a>
</div>
</body>
</html>