| [/ |
| / Copyright (c) 2003-2010 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| / |
| / Distributed under the Boost Software License, Version 1.0. (See accompanying |
| / file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| /] |
| |
| [section:ResolveHandler Resolve handler requirements] |
| |
| A resolve handler must meet the requirements for a [link |
| boost_asio.reference.Handler handler]. A value `h` of a resolve handler |
| class should work correctly in the expression `h(ec, i)`, where `ec` is an |
| lvalue of type `const error_code` and `i` is an lvalue of type `const |
| ip::basic_resolver_iterator<InternetProtocol>`. `InternetProtocol` is the |
| template parameter of the [link boost_asio.reference.ip__resolver_service |
| `resolver_service`] which is used to initiate the asynchronous operation. |
| |
| [heading Examples] |
| |
| A free function as a resolve handler: |
| |
| void resolve_handler( |
| const boost::system::error_code& ec, |
| boost::asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| |
| A resolve handler function object: |
| |
| struct resolve_handler |
| { |
| ... |
| void operator()( |
| const boost::system::error_code& ec, |
| boost::asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| ... |
| }; |
| |
| A non-static class member function adapted to a resolve handler using `bind()`: |
| |
| void my_class::resolve_handler( |
| const boost::system::error_code& ec, |
| boost::asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| ... |
| resolver.async_resolve(..., |
| boost::bind(&my_class::resolve_handler, |
| this, boost::asio::placeholders::error, |
| boost::asio::placeholders::iterator)); |
| |
| [endsect] |