On Fri, 2005-11-04 at 12:28 +0100, Segher Boessenkool wrote: > > You can reliably use 0 as a null pointer constant with one exception. > > When calling a varargs function which expects a pointer as an unnamed > > argument, and when pointers are 64-bits but int is 32-bits, then you > > must either use NULL or you must cast 0 to a pointer type. > > Using NULL in this case is not portable; you *must* > use a cast to the exact pointer type that the > varargs function expects to see. Different pointer > types can have different representation. However, it does seem that must platforms understand NULL and assigns the correct type. I do agree that for portability we should use the cast. Ernest > > > Segher >
