Xref: utzoo comp.lang.c:6668 comp.sys.m68k:682
Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!umd5!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c,comp.sys.m68k
Subject: Re: C machine
Message-ID: <7117@brl-smoke.ARPA>
Date: 18 Jan 88 01:11:09 GMT
References: <461@auvax.UUCP> <9961@mimsy.UUCP> <166@teletron.UUCP> <6936@brl-smoke.ARPA> <147@ateng.UUCP> <39aca826.7f32@apollo.uucp> <7092@brl-smoke.ARPA> <708@umbc3.UMD.EDU> <7109@brl-smoke.ARPA> <712@umbc3.UMD.EDU>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 20

In article <712@umbc3.UMD.EDU> alex@umbc3.UMD.EDU (Alex S. Crain) writes:
>	I don't really understand the answer, I think you said "impementation
>dependant". If so, how is that a fix?

It *is* implementation-dependent, whether or not you like it that way.
The "fix" is to quit insisting that ptrdiff_t has to be int and to permit
it to be long where necessary.

> when ... i say 
>	funcall (ptr1 - ptr2); /* ptr1 - ptr2 > 64k */
>what happens? or do I just check stddef.h for the answer?

What do you mean, what happens?  You pass an argument having some signed
integral type to funcall().  Presumably you have properly declared
funcall() as in
	extern void funcall( ptrdiff_t );

If you don't like using a type other than a known basic type, you can of
course coerce the ptrdiff_t into a long via a (long) cast, but seldom is
this necessary or useful.  (It is necessary if you're going to printf()
the value of a ptrdiff_t.)