Signed to unsigned comparison

[Henry Spencer]

In article <40472 at cup.portal.com> PLS at 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 at zoo.toronto.edu  utzoo!henry