Path: utzoo!utgpu!water!watmath!rbutterworth
From: rbutterworth@watmath.waterloo.edu (Ray Butterworth)
Newsgroups: comp.lang.c
Subject: Another way (How not to write a loop)
Message-ID: <16941@watmath.waterloo.edu>
Date: 15 Feb 88 15:09:15 GMT
References: <560@naucse.UUCP> <1988Feb11.200149.25172@sq.uucp> <2115@bsu-cs.UUCP>
Organization: U of Waterloo, Ontario
Lines: 17

I just got hit by yet another way not to write a loop:

    auto size_t index;

    index = sizeof(array) / sizeof(array[0]);

    while (--index >= 0)
        blah blah blah

This looks wonderfully portable and works fine on the BSD 4.3 compiler
(and probably most others).

But on an ANSI compiler, (size_t) will be an unsigned integer
and the loop will go forever.

Lint will notice this problem, but only with the ANSI compiler
when it is probably too late.