Xref: utzoo comp.sys.ibm.pc:22103 comp.sys.intel:593
Path: utzoo!attcan!uunet!tektronix!sequent!sch
From: sch@sequent.UUCP (Steve Hemminger)
Newsgroups: comp.sys.ibm.pc,comp.sys.intel
Subject: Re: correct code for pointer subtraction
Summary: ptr subtract only in same array
Message-ID: <8455@sequent.UUCP>
Date: 11 Dec 88 19:55:46 GMT
References: <597@mks.UUCP> <8377@bloom-beacon.MIT.EDU>
Reply-To: sch@crg2.UUCP (Steve Hemminger)
Organization: Sequent Computer Systems, Inc
Lines: 5

I believe the ANSI std and K&R say pointer subtraction is only allowed inside
one data structure/array.  Since the small/medium/large model only allows
arrays <64K, only a 16bit result needs to be computed. Any code that
depends on subtracting pointers into two totally seperate arrays is
non-portable.