A read handler must meet the requirements for a handler.
A value h
of a read 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 read handler:
void read_handler( const asio::error_code& ec, std::size_t bytes_transferred) { ... }
A read handler function object:
struct read_handler { ... void operator()( const asio::error_code& ec, std::size_t bytes_transferred) { ... } ... };
A lambda as a read handler:
socket.async_read(... [](const asio::error_code& ec, std::size_t bytes_transferred) { ... });
A non-static class member function adapted to a read handler using std::bind()
:
void my_class::read_handler( const asio::error_code& ec, std::size_t bytes_transferred) { ... } ... socket.async_read(..., std::bind(&my_class::read_handler, this, std::placeholders::_1, std::placeholders::_2));
A non-static class member function adapted to a read handler using boost::bind()
:
void my_class::read_handler( const asio::error_code& ec, std::size_t bytes_transferred) { ... } ... socket.async_read(..., boost::bind(&my_class::read_handler, this, asio::placeholders::error, asio::placeholders::bytes_transferred));