Move-assign
a basic_serial_port
from another.
basic_serial_port & operator=( basic_serial_port && other);
This assignment operator moves a serial port from one object to another.
The other basic_serial_port
object
from which the move will occur.
Following the move, the moved-from object is in the same state as if constructed
using the basic_serial_port(const executor_type&)
constructor.