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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="boost_asio.reference.basic_socket.async_connect"></a><a class="link" href="async_connect.html" title="basic_socket::async_connect">basic_socket::async_connect</a>
  28 </h4></div></div></div>
  29 <p>
  30           <a class="indexterm" name="idp112950160"></a>
  31 Start an asynchronous connect.
  32         </p>
  33 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  34     <span class="keyword">typename</span> <a class="link" href="../ConnectHandler.html" title="Connect handler requirements">ConnectHandler</a><span class="special">&gt;</span>
  35 <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.return_type_of_an_initiating_function"><span class="emphasis"><em>void-or-deduced</em></span></a> <span class="identifier">async_connect</span><span class="special">(</span>
  36     <span class="keyword">const</span> <span class="identifier">endpoint_type</span> <span class="special">&amp;</span> <span class="identifier">peer_endpoint</span><span class="special">,</span>
  37     <span class="identifier">ConnectHandler</span> <span class="identifier">handler</span><span class="special">);</span>
  38 </pre>
  39 <p>
  40           This function is used to asynchronously connect a socket to the specified
  41           remote endpoint. The function call always returns immediately.
  42         </p>
  43 <p>
  44           The socket is automatically opened if it is not already open. If the connect
  45           fails, and the socket was automatically opened, the socket is not returned
  46           to the closed state.
  47         </p>
  48 <h6>
  49 <a name="boost_asio.reference.basic_socket.async_connect.h0"></a>
  50           <span class="phrase"><a name="boost_asio.reference.basic_socket.async_connect.parameters"></a></span><a class="link" href="async_connect.html#boost_asio.reference.basic_socket.async_connect.parameters">Parameters</a>
  51         </h6>
  52 <div class="variablelist">
  53 <p class="title"><b></b></p>
  54 <dl class="variablelist">
  55 <dt><span class="term">peer_endpoint</span></dt>
  56 <dd><p>
  57                 The remote endpoint to which the socket will be connected. Copies
  58                 will be made of the endpoint object as required.
  59               </p></dd>
  60 <dt><span class="term">handler</span></dt>
  61 <dd>
  62 <p>
  63                 The handler to be called when the connection operation completes.
  64                 Copies will be made of the handler as required. The function signature
  65                 of the handler must be:
  66 </p>
  67 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span>
  68   <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">error</span> <span class="comment">// Result of operation</span>
  69 <span class="special">);</span>
  70 </pre>
  71 <p>
  72                 Regardless of whether the asynchronous operation completes immediately
  73                 or not, the handler will not be invoked from within this function.
  74                 Invocation of the handler will be performed in a manner equivalent
  75                 to using <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">io_service</span><span class="special">::</span><span class="identifier">post</span><span class="special">()</span></code>.
  76               </p>
  77 </dd>
  78 </dl>
  79 </div>
  80 <h6>
  81 <a name="boost_asio.reference.basic_socket.async_connect.h1"></a>
  82           <span class="phrase"><a name="boost_asio.reference.basic_socket.async_connect.example"></a></span><a class="link" href="async_connect.html#boost_asio.reference.basic_socket.async_connect.example">Example</a>
  83         </h6>
  84 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">connect_handler</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">error</span><span class="special">)</span>
  85 <span class="special">{</span>
  86   <span class="keyword">if</span> <span class="special">(!</span><span class="identifier">error</span><span class="special">)</span>
  87   <span class="special">{</span>
  88     <span class="comment">// Connect succeeded.</span>
  89   <span class="special">}</span>
  90 <span class="special">}</span>
  91
  92 <span class="special">...</span>
  93
  94 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">ip</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="identifier">io_service</span><span class="special">);</span>
  95 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">endpoint</span> <span class="identifier">endpoint</span><span class="special">(</span>
  96     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">ip</span><span class="special">::</span><span class="identifier">address</span><span class="special">::</span><span class="identifier">from_string</span><span class="special">(</span><span class="string">"1.2.3.4"</span><span class="special">),</span> <span class="number">12345</span><span class="special">);</span>
  97 <span class="identifier">socket</span><span class="special">.</span><span class="identifier">async_connect</span><span class="special">(</span><span class="identifier">endpoint</span><span class="special">,</span> <span class="identifier">connect_handler</span><span class="special">);</span>
  98 </pre>
  99 </div>
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