[/ / Copyright (c) 2003-2019 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:RangeConnectHandler Range connect handler requirements] A range connect handler must meet the requirements for a [link boost_asio.reference.Handler handler]. A value `h` of a range connect handler class should work correctly in the expression `h(ec, ep)`, where `ec` is an lvalue of type `const error_code` and `ep` is an lvalue of the type `Protocol::endpoint` for the `Protocol` type in the corresponding `connect()` or async_connect()` function. [heading Examples] A free function as a range connect handler: void connect_handler( const boost::system::error_code& ec, const boost::asio::ip::tcp::endpoint& endpoint) { ... } A range connect handler function object: struct connect_handler { ... template void operator()( const boost::system::error_code& ec, const boost::asio::ip::tcp::endpoint& endpoint) { ... } ... }; A lambda as a range connect handler: boost::asio::async_connect(..., [](const boost::system::error_code& ec, const boost::asio::ip::tcp::endpoint& endpoint) { ... }); A non-static class member function adapted to a range connect handler using `std::bind()`: void my_class::connect_handler( const boost::system::error_code& ec, const boost::asio::ip::tcp::endpoint& endpoint) { ... } ... boost::asio::async_connect(..., std::bind(&my_class::connect_handler, this, std::placeholders::_1, std::placeholders::_2)); A non-static class member function adapted to a range connect handler using `boost::bind()`: void my_class::connect_handler( const boost::system::error_code& ec, const boost::asio::ip::tcp::endpoint& endpoint) { ... } ... boost::asio::async_connect(..., boost::bind(&my_class::connect_handler, this, boost::asio::placeholders::error, boost::asio::placeholders::endpoint)); [endsect]