Move-assign
a basic_deadline_timer
from another.
basic_deadline_timer & operator=( basic_deadline_timer && other);
This assignment operator moves a timer from one object to another. Cancels any outstanding asynchronous operations associated with the target object.
The other basic_deadline_timer
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_deadline_timer(io_context&) constructor
.