| [/ |
| / Copyright (c) 2003-2021 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:IteratorConnectHandler Iterator connect handler requirements] |
| |
| An iterator connect handler must meet the requirements for a [link |
| asio.reference.Handler handler]. A value `h` of an iterator connect 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 the type `Iterator` |
| used in the corresponding `connect()` or async_connect()` function. |
| |
| [heading Examples] |
| |
| A free function as an iterator connect handler: |
| |
| void connect_handler( |
| const asio::error_code& ec, |
| asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| |
| An iterator connect handler function object: |
| |
| struct connect_handler |
| { |
| ... |
| template <typename Iterator> |
| void operator()( |
| const asio::error_code& ec, |
| Iterator iterator) |
| { |
| ... |
| } |
| ... |
| }; |
| |
| A lambda as an iterator connect handler: |
| |
| asio::async_connect(..., |
| [](const asio::error_code& ec, |
| asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| }); |
| |
| A non-static class member function adapted to an iterator connect handler using |
| `std::bind()`: |
| |
| void my_class::connect_handler( |
| const asio::error_code& ec, |
| asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| ... |
| asio::async_connect(..., |
| std::bind(&my_class::connect_handler, |
| this, std::placeholders::_1, |
| std::placeholders::_2)); |
| |
| A non-static class member function adapted to an iterator connect handler using |
| `boost::bind()`: |
| |
| void my_class::connect_handler( |
| const asio::error_code& ec, |
| asio::ip::tcp::resolver::iterator iterator) |
| { |
| ... |
| } |
| ... |
| asio::async_connect(..., |
| boost::bind(&my_class::connect_handler, |
| this, asio::placeholders::error, |
| asio::placeholders::iterator)); |
| |
| [endsect] |