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From: mouse@mcgill-vision.UUCP (der Mouse)
Newsgroups: comp.lang.c
Subject: Re: char (*a)[]  (was: Style [++i vs i++])
Message-ID: <871@mcgill-vision.UUCP>
Date: Wed, 26-Aug-87 04:18:01 EDT
Article-I.D.: mcgill-v.871
Posted: Wed Aug 26 04:18:01 1987
Date-Received: Sun, 6-Sep-87 03:09:47 EDT
References: <8298@brl-adm.ARPA> <587@cblpe.ATT.COM> <189@xyzzy.UUCP> <2310@mmintl.UUCP>
Organization: McGill University, Montreal
Lines: 22

In article <2310@mmintl.UUCP>, franka@mmintl.UUCP (Frank Adams) writes:
> In article <1987Aug10.192923.7879@sq.uucp> msb@sq.UUCP (Mark Brader) writes:
>> Wayne Throop writes:
>>> ... but *also* because it performs arithmetic on a null pointer,
>>> and of course, this is illegal.)
>> Um, I don't think so, Wayne; it's just that the result, if you
>> indirect through such a pointer, is undefined.
> Operations which produce undefined results are a special case of
> illegal operations.

Yes.  But arithmetic on a null pointer is not what Mark was saying
produces undefined results, it's indirecting through the result.  And
the sample program didn't indirect through the pointer after it did the
arithmetic.

(Of course, arithmetic on a null pointer may *also* be illegal, or
produce undefined results, I don't know for sure.  But that's not my
point.)

					der Mouse

				(mouse@mcgill-vision.uucp)