Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!purdue!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.unix.wizards
Subject: Re: Invalid Pointers
Message-ID: <10541@smoke.BRL.MIL>
Date: 17 Jul 89 15:08:13 GMT
References: <20245@adm.BRL.MIL> <4348@eos.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Followup-To: comp.lang.c
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 10

In article <4348@eos.UUCP> jbm@eos.UUCP (Jeffrey Mulligan) writes:
-It has been pointed out that there should be no assumptions
-about what addresses are valid; is there any way to get
-a guaranteed INVALID address?

A null pointer is guaranteed not to match any valid object address.

-#define NO_FOOBAR ((struct foobar *) -1 )	is what I use, but...

This is not portable.  Just use NULL.