Move-assign
a windows::random_access_handle
from another.
random_access_handle & operator=( random_access_handle && other);
This assignment operator moves a random-access handle from one object to another.
The other windows::random_access_handle
object from which the move will occur.
Following the move, the moved-from object is in the same state as if constructed
using the random_access_handle(io_context&)
constructor.