item.g.r = get(queue.s.r)
This method returns the element at the head of the Queue,
removing element from the Queue.
queue a pointer to the queue (structure of type Queue)
This function returns:
a pointer to the item at the head of the Queue.
Use of this class requires the following header files:
create_Queue() the constructor for instances of the Queue class
ptr = (*queue->get)(queue);
if (ptr != (void *) NULL)
item = *ptr;
The Queue class actually allocates space in which to store the
data item given to it for the "put" operation. It is a pointer
to this allocated space that is returned by this method.
Therefore the user of the Queue class must be sure to free
this pointer when finished with it, or else memory leaks will