Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 13 Apr 2012 17:44:37 -0700 | Subject | Re: [PATCH][RESEND] do not redefine userspace's NULL #define |
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On Fri, Apr 13, 2012 at 4:18 PM, Lubos Lunak <l.lunak@suse.cz> wrote: >> imagine replacing the kernel ((void *)0) with __null. > > __null apparently exists only with g++, C does not have the stronger type > safety that prevents ((void*)0) from being usable in C++
Please don't continue to spread this total bogosity.
The reason C++ cannot use "(void *)0" has nothing to do with "stronger type safety". That's a total idiotic lie by C++ apologists, and I hate hearing it repeated over and over again.
And it really *is* a lie. The C++ type system isn't even "stronger", it's just different, and it's actively *broken* wrt NULL. Always has been.
The sane thing to do for C++ would always have been to recognize that "(void *)0" is not a "void pointer" - it's just NULL. INSTEAD, the morons involved said "no, it's a void pointer, and instead we'll make '0' be NULL".
Which is clearly insane, but is also technically simply *wrong*.
0 is an integer, it's not NULL _either_, and it's just a more stupid version of NULL.
So the C++ people then completely made up the argument that "C++ has a stronger type system, we can't use 'void *', so the C style ((void *)0) is wrong for C++".
Which is utter and complete bullshit, and any amount of brains would have realized that (since C++ at the same time happily continued to special case the *integer* zero).
I don't hate __null, but I absolutely despise the crazy C++ apologists who try to claim that C++ was somehow "right" in not accepting (void *)0, and that it was somehow about "type safety". No, it was not. It has always been just nothing but a moronic hang-up, and it has always been *wrong*.
So don't spread that lie. It was wrong. The fact is, the *constant* 0 is the special one, and C++ could have (and should have) just accepted that that constant should have been cast to (void *) and that is what NULL is defined to. Instead, C++ used the *weaker* type system of saying that the *integer* constant 0 is NULL, which is pure and utter garbage.
And then they lie, and claim that their *weaker* type system NULL is "stronger". Pure idiocy.
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