...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
A connect handler must meet the requirements for a handler.
A value h
of a connect handler class should work correctly in
the expression h(ec)
, where ec
is an lvalue of
type const error_code
.
A free function as a connect handler:
void connect_handler( const boost::system::error_code& ec) { ... }
A connect handler function object:
struct connect_handler { ... void operator()( const boost::system::error_code& ec) { ... } ... };
A lambda as a connect handler:
socket.async_connect(..., [](const boost::system::error_code& ec) { ... });
A non-static class member function adapted to a connect handler using std::bind()
:
void my_class::connect_handler( const boost::system::error_code& ec) { ... } ... socket.async_connect(..., std::bind(&my_class::connect_handler, this, std::placeholders::_1));
A non-static class member function adapted to a connect handler using boost::bind()
:
void my_class::connect_handler( const boost::system::error_code& ec) { ... } ... socket.async_connect(..., boost::bind(&my_class::connect_handler, this, boost::asio::placeholders::error));