pointers, tests, casts

[Doug Gwyn]

In article <226 at twwells.uucp> bill at twwells.UUCP (T. William Wells) writes:
>Otherwise, there are are implementations, those defining NULL as
>(char *)0, which will give an error on the latter statement.

The only valid definitions for NULL are 0 and ((void*)0).
As you say, implementations exist that do this wrong.