first=last=Null;
is an error because Null
should be NULL
(all-caps). No need to declare/define NULL
, it's in your implementations header files already (in your case, <iostream>
).
Actually, you'll find that NULL
is actually just a macro which expands to 0
(or (void*)0
). ie #define NULL (void*)0
.
Let me know if this fixes both errors.