Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!eru!luth!sunic!mcsun!ukc!edcastle!aiai!richard
From: richard@aiai.ed.ac.uk (Richard Tobin)
Newsgroups: comp.std.c
Subject: Re: Out-of-bounds pointers
Message-ID: <1224@skye.ed.ac.uk>
Date: 13 Oct 89 13:18:01 GMT
References: <240@bbxsda.UUCP> <11265@smoke.BRL.MIL>
Reply-To: richard@aiai.UUCP (Richard Tobin)
Organization: AIAI, University of Edinburgh, Scotland
Lines: 16

In article <11265@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn) writes:
>Not at all.  In any block-structured language with pointers,
>it is obvious how to have a valid pointer suddenly become invalid.

Doug is quite right as far as C goes - just take the address of an
automatic variable.  But it's not true for *any* block-structured 
language with pointers, because the language can prevent it.  Algol 68
is an example of such a language.  (REF != pointer flames >/dev/null)

-- Richard


-- 
Richard Tobin,                       JANET: R.Tobin@uk.ac.ed             
AI Applications Institute,           ARPA:  R.Tobin%uk.ac.ed@nsfnet-relay.ac.uk
Edinburgh University.                UUCP:  ...!ukc!ed.ac.uk!R.Tobin