...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
A write handler must meet the requirements for a handler.
A value h
of a write handler
class should work correctly in the expression h(ec,
s)
,
where ec
is an lvalue of
type const error_code
and s
is an lvalue of type
const size_t
.
A free function as a write handler:
void write_handler( const boost::system::error_code& ec, std::size_t bytes_transferred) { ... }
A write handler function object:
struct write_handler { ... void operator()( const boost::system::error_code& ec, std::size_t bytes_transferred) { ... } ... };
A non-static class member function adapted to a write handler using bind()
:
void my_class::write_handler( const boost::system::error_code& ec, std::size_t bytes_transferred) { ... } ... socket.async_write(..., boost::bind(&my_class::write_handler, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));