On Mar 11 2007 18:01, Kyle Moffett wrote: > On Mar 11, 2007, at 16:41:51, Daniel Hazelton wrote: >> On Sunday 11 March 2007 16:35:50 Jan Engelhardt wrote: >> > On Mar 11 2007 22:15, Cong WANG wrote: >> > > So can I say using NULL is better than 0 in kernel? >> > >> > On what basis? Do you even know what NULL is defined as in (C, not >> > C++) userspace? Think about it. >> >> IIRC, the glibc and GCC headers define NULL as (void*)0 :) > > On the other hand when __cplusplus is defined they define it to the > "__null" builtin, which GCC uses to give type conversion errors for > "int foo = NULL" but not "char *foo = NULL". A "((void *)0)" > definition gives C++ type errors for both due to the broken C++ > void pointer conversion problems.
I think that the primary reason they use __null is so that you can actually do class foo *ptr = NULL; because class foo *ptr = (void *)0; would throw an error or at least a warning (implicit cast from void* to class foo*). Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/