item.g.r = get(aList.s.r)
This method returns the element at the head of the aList,
removing element from the aList.
aList a pointer to the aList (structure of type aList)
This function returns:
a pointer to the item at the head of the aList.
Use of this class requires the following header files:
create_aList() the constructor for instances of the aList class
ptr = (*aList->get)(aList);
if (ptr != (void *) NULL)
item = *ptr;
The aList 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 aList class must be sure to free
this pointer when finished with it, or else memory leaks will