Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: Invalid Pointers
Message-ID: <10547@smoke.BRL.MIL>
Date: 19 Jul 89 05:40:29 GMT
References: <20245@adm.BRL.MIL> <4348@eos.UUCP> <10541@smoke.BRL.MIL> <8990@chinet.chi.il.us>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 13

In article <8990@chinet.chi.il.us> les@chinet.chi.il.us (Leslie Mikesell) writes:
-In article <10541@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
->>#define NO_FOOBAR ((struct foobar *) -1 )	is what I use, but...
->This is not portable.  Just use NULL.
-Do you mean that there are machines that might return a valid -1 from
-sbrk(2) or shmat(2), or that would misconstrue the comparsion of
-a pointer to -1?

What I mean is what I said.

-Yes, I know these are botches, but are they not always accomodated?

No.  Non-UNIX systems need not even try to accommodate them.