Construct a stream handle without opening it.
template< typename ExecutionContext> basic_stream_handle( ExecutionContext & context, typename constraint< is_convertible< ExecutionContext &, execution_context & >::value, defaulted_constraint >::type = defaulted_constraint());
This constructor creates a stream handle without opening it. The handle needs to be opened or assigned before data can be sent or received on it.
An execution context which provides the I/O executor that the stream handle will use, by default, to dispatch handlers for any asynchronous operations performed on the stream handle.