Remove up to the specified maxNumItems from the back of this container. Optionally specify a buffer into which the items removed from the container are loaded. If buffer is non-null, the removed items are appended to it as if by repeated application of buffer->push_back(popBack()) while the container is not empty and maxNumItems have not yet been removed. Note that the ordering of the items in *buffer after the call is the reverse of the ordering they had in the deque. Also note that *buffer is not cleared -- the popped items are appended after any pre-existing contents.
Also note that to transfer the entire contents of a Deque d to a vector v, use d.removeAll(&v);.