asio/doc/requirements/WaitHandler.qbk
2019-02-17 19:59:39 -10:00

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[/
/ 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:WaitHandler Wait handler requirements]
A wait handler must meet the requirements for a [link
boost_asio.reference.Handler handler]. A value `h` of a wait handler class
should work correctly in the expression `h(ec)`, where `ec` is an lvalue of
type `const error_code`.
[heading Examples]
A free function as a wait handler:
void wait_handler(
const boost::system::error_code& ec)
{
...
}
A wait handler function object:
struct wait_handler
{
...
void operator()(
const boost::system::error_code& ec)
{
...
}
...
};
A lambda as a wait handler:
socket.async_wait(...,
[](const boost::system::error_code& ec)
{
...
});
A non-static class member function adapted to a wait handler using
`std::bind()`:
void my_class::wait_handler(
const boost::system::error_code& ec)
{
...
}
...
socket.async_wait(...,
std::bind(&my_class::wait_handler,
this, std::placeholders::_1));
A non-static class member function adapted to a wait handler using
`boost::bind()`:
void my_class::wait_handler(
const boost::system::error_code& ec)
{
...
}
...
socket.async_wait(...,
boost::bind(&my_class::wait_handler,
this, boost::asio::placeholders::error));
[endsect]