Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Signed to unsigned comparison
Message-ID: <1991Mar24.001308.12852@zoo.toronto.edu>
Date: Sun, 24 Mar 1991 00:13:08 GMT
References: <40472@cup.portal.com>
Organization: U of Toronto Zoology

In article <40472@cup.portal.com> PLS@cup.portal.com (Paul L Schauble) writes:
>What should a compiler do with the comparison in this example:
>    unsigned int a;
>
>    a = 5;
>    if (a > -1) ....

The infamous "usual arithmetic conversions" apply.  The -1 is converted to
`unsigned int', probably giving something like 65535 or 2147483647, and
then the comparison is done, probably not giving the result you expect.

What a compiler *should* do is give you a warning about this.
-- 
"[Some people] positively *wish* to     | Henry Spencer @ U of Toronto Zoology
believe ill of the modern world."-R.Peto|  henry@zoo.toronto.edu  utzoo!henry