Date: Tue, 20 Aug 2002 18:01:00 -0700 (PDT) From: Archie Cobbs <archie@dellroad.org> To: obrien@freebsd.org Cc: freebsd-arch@freebsd.org Subject: Re: NULL Message-ID: <200208210101.g7L110m03801@arch20m.dellroad.org> In-Reply-To: <20020821002116.GA33223@dragon.nuxi.com> "from David O'Brien at Aug 20, 2002 05:21:16 pm"
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David O'Brien writes:
> > Simple question...
> > Why isn't NULL defined to be "((void *)0)" instead of "0" ?
>
> In C++ this is not legal:
>
> void blah(void) {
> int *foo;
> void *bar;
> bar = foo;
> foo = bar;
> }
>
> it is in C, but we share the definition.
> A benefit of "(void *)0" is that this would be caught:
>
> char c = NULL;
>
> rather than the correct:
> char c = '\0';
>
When you say "not legal" do you mean it causes an error or a warning?
If it's just a warning, then are you saying the reason we don't use
(void *)0 is because we would lose the C++ warning to gain the C warning?
Seems like a fair trade to me :-)
FYI, this question came up when porting some code to redhat Linux, where
NULL is defined as (void *)0.
Thanks,
-Archie
__________________________________________________________________________
Archie Cobbs * Packet Design * http://www.packetdesign.com
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