Treating the abusive unsigned syndrome

[Andrei Alexandrescu]

bearophile wrote:
>> Walter, as many good long-time C programmers, knows the abusive 
>> unsigned rule so well he's not hurt by it and consequently has
>> little incentive to see it as a problem.
> 
> I'm not a newbie of programming, but in the last year I have put in
> my code two bugs related to this, so I suggest to find ways to avoid
> this silly situation. I think the first bug was something like: if
> (arr.lenght > x) ...

> where x was a signed int with value -5 (this specific bug can also be
> solved making array length a signed value. What's the point of making
> it unsigned in the first place? I have seen that in D it's safer to
> use signed values everywhere you don't strictly need an unsigned
> value. And that length doesn't need to be unsigned).

It's worthwhile keeping length an unsigned type if we can convincingly 
sell unsigned types as models of natural numbers. With the current 
rules, we can't make a convincing argument. But if we do manage to 
improve the rules, then we'll all be better off.

Andrei