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26 <div class="titlepage"><div><div><h5 class="title">
27 <a name="boost_asio.reference.ip__basic_resolver.async_resolve.overload2"></a><a class="link" href="overload2.html" title="ip::basic_resolver::async_resolve (2 of 6 overloads)">ip::basic_resolver::async_resolve
28 (2 of 6 overloads)</a>
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31 Asynchronously perform forward resolution of a query to a list of entries.
33 <pre class="programlisting">template<
34 typename <a class="link" href="../../ResolveHandler.html" title="Resolve handler requirements">ResolveHandler</a> = <a class="link" href="../../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>>
35 <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_resolve(
38 ResolveHandler && 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 This function is used to resolve host and service names into a list of
45 <a name="boost_asio.reference.ip__basic_resolver.async_resolve.overload2.h0"></a>
46 <span class="phrase"><a name="boost_asio.reference.ip__basic_resolver.async_resolve.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.ip__basic_resolver.async_resolve.overload2.parameters">Parameters</a>
48 <div class="variablelist">
49 <p class="title"><b></b></p>
50 <dl class="variablelist">
51 <dt><span class="term">host</span></dt>
53 A string identifying a location. May be a descriptive name or a
54 numeric address string. If an empty string and the passive flag
55 has been specified, the resolved endpoints are suitable for local
56 service binding. If an empty string and passive is not specified,
57 the resolved endpoints will use the loopback address.
59 <dt><span class="term">service</span></dt>
61 A string identifying the requested service. This may be a descriptive
62 name or a numeric string corresponding to a port number. May be
63 an empty string, in which case all resolved endpoints will have
66 <dt><span class="term">handler</span></dt>
69 The handler to be called when the resolve operation completes.
70 Copies will be made of the handler as required. The function signature
71 of the handler must be:
73 <pre class="programlisting">void handler(
74 const boost::system::error_code& error, // Result of operation.
75 resolver::results_type results // Resolved endpoints as a range.
79 Regardless of whether the asynchronous operation completes immediately
80 or not, the handler will not be invoked from within this function.
81 On immediate completion, invocation of the handler will be performed
82 in a manner equivalent to using <a class="link" href="../../post.html" title="post"><code class="computeroutput">post</code></a>.
88 A successful resolve operation is guaranteed to pass a non-empty range
92 <a name="boost_asio.reference.ip__basic_resolver.async_resolve.overload2.h1"></a>
93 <span class="phrase"><a name="boost_asio.reference.ip__basic_resolver.async_resolve.overload2.remarks"></a></span><a class="link" href="overload2.html#boost_asio.reference.ip__basic_resolver.async_resolve.overload2.remarks">Remarks</a>
96 On POSIX systems, host names may be locally defined in the file <code class="computeroutput">/etc/hosts</code>.
97 On Windows, host names may be defined in the file <code class="computeroutput">c:\windows\system32\drivers\etc\hosts</code>.
98 Remote host name resolution is performed using DNS. Operating systems
99 may use additional locations when resolving host names (such as NETBIOS
103 On POSIX systems, service names are typically defined in the file <code class="computeroutput">/etc/services</code>.
104 On Windows, service names may be found in the file <code class="computeroutput">c:\windows\system32\drivers\etc\services</code>.
105 Operating systems may use additional locations when resolving service
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111 <td align="right"><div class="copyright-footer">Copyright © 2003-2019 Christopher M. Kohlhoff<p>
112 Distributed under the Boost Software License, Version 1.0. (See accompanying
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