In article <2390 at krafla.rhi.hi.is> einari at rhi.hi.is (Einar Indridason) writes: > x = do_something(NULL, NULL, NULL); > /* is ^^^^ ^^^^ ^^^^ this right or should I write: */ > x = do_something( (int *)NULL, (double *)NULL, (char *)NULL ); Use the latter. The former might or might not work, depending on system details.