Re: warning: comparison between signed and unsigned integer expressions

On Tue, Apr 20, 2010 at 23:14, Clark Cox <[email protected]> wrote:
> On Tue, Apr 20, 2010 at 1:59 PM, Stephen Hoffman <[email protected]> wrote:
>> Have a look around for the value-preserving and unsigned-preserving discussions; current C tends to be value-preserving.
>
> The value-preserving behavior is mandated by the C standard wherever possible.

I feel I should know this, but I had to do a test to find what exactly
you meant by "value-preserving".

int a;
unsigned int b;

a = -1;
b = (int) a;

What is 'b'?

As it turns out, it's 4294967295 or 0xFFFFFFFF

BTW for the original poster, if all you're doing is equality
comparisons (or not equal) a simple case tends to be fine, just be
careful with < & >. -1 suddenly becomes greater than zero.