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From: brnstnd@stealth.acf.nyu.edu
Newsgroups: comp.std.c
Subject: a[], *p: if 0 <= p - a < sizeof(a), must p point to an element of a?
Message-ID: <875@stealth.acf.nyu.edu>
Date: 4 Jan 90 18:39:53 GMT
Sender: brnstnd@stealth.acf.nyu.edu
Reply-To: brnstnd@stealth.acf.nyu.edu (Dan Bernstein)
Distribution: usa
Organization: IR
Lines: 8

Basically, I want to have a guaranteed test of whether p points to an
element of a, with foo a[N] and foo *p. I know that *if* p points to an
element of a, *then* 0 <= p - a < sizeof(a); is the reverse true? (If
yes, please explain the logic.)

The standard should define pointer subtraction more carefully.

---Dan