Calling dataclasses.replace(instance, **changes) returns a new object of the same type.

From my understanding there is, however, no method to update in place fields of a dataclass from another one.

I propose to add dataclasses.update(instance_to_update, other_instance, **changes).

This would for instance allow one to change all fields of current object in a sturdy way.
In my case, I currently call obj.__dict__.update(other_obj.__dict__) to perform the operation, but I know it has always to be done pretty carefully.

If this is accepted, I'm willing to post the change.