| [/ |
| / 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:LegacyCompletionHandler Legacy completion handler requirements] |
| |
| A legacy completion handler must meet the requirements for a [link |
| asio.reference.Handler handler]. A legacy completion handler must meet the |
| requirements of `CopyConstructible` types (C++Std [copyconstructible]). A value |
| `h` of a completion handler class should work correctly in the expression |
| `h()`. |
| |
| [heading Examples] |
| |
| A free function as a completion handler: |
| |
| void completion_handler() |
| { |
| ... |
| } |
| |
| A completion handler function object: |
| |
| struct completion_handler |
| { |
| ... |
| void operator()() |
| { |
| ... |
| } |
| ... |
| }; |
| |
| A lambda as a completion handler: |
| |
| my_io_service.post( |
| []() |
| { |
| ... |
| }); |
| |
| A non-static class member function adapted to a completion handler using |
| `std::bind()`: |
| |
| void my_class::completion_handler() |
| { |
| ... |
| } |
| ... |
| my_io_service.post(std::bind(&my_class::completion_handler, this)); |
| |
| A non-static class member function adapted to a completion handler using |
| `boost::bind()`: |
| |
| void my_class::completion_handler() |
| { |
| ... |
| } |
| ... |
| my_io_service.post(boost::bind(&my_class::completion_handler, this)); |
| |
| [endsect] |