Path: utzoo!attcan!uunet!mcvax!ukc!harrier.ukc.ac.uk!mtr
From: mtr@ukc.ac.uk (M.T.Russell)
Newsgroups: comp.lang.c
Subject: Re: %p and different pointer representations
Message-ID: <248@harrier.ukc.ac.uk>
Date: 28 Feb 89 13:42:08 GMT
References: <9382@bloom-beacon.MIT.EDU> <234@mstan.Morgan.COM> <591@jhereg.Jhereg.MN.ORG> <9730@smoke.BRL.MIL>
Reply-To: mtr@ukc.ac.uk (M.T.Russell)
Organization: Computing Lab, University of Kent at Canterbury, UK.
Lines: 21

In article <9730@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
>A function pointer may well not fit into a void*.

This presumably implies that comparison and assignment between function
pointers and void* pointers is illegal, and thus that

	f = NULL;

and

	if (f == NULL)

are both illegal if f is a function pointer and NULL is defined as (void *)0.
If this is so, then I don't see that (void *)0 is a reasonable definition
of NULL.

Is (void *)0 a special case?  Gcc 1.32 -ansi -pedantic doesn't think so -
it objects to the above constructs.

Mark Russell
mtr@ukc.ac.uk