Move-assign an object handle from a handle of another executor type.
template< typename Executor1> constraint< is_convertible< Executor1, Executor >::value, basic_object_handle & >::type operator=( basic_object_handle< Executor1 > && other);
This assignment operator moves an object handle from one object to another.
The other object 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 basic_object_handle(const executor_type&)
constructor.