My Kingdom For ...

[Don Clugston]

Janice Caron wrote:
> On 24/02/2008, Janice Caron <caron800 at googlemail.com> wrote:
>> I think it would be better if widening type promotions were not done
>>  where not necessary.

Yes. But that's more work right now.
> 
> "where not necessary" now becomes the problem. When is it necessary?
> 
>     ubyte n = 255;
>     auto m = n + 2;
> 
> what type is m?
> 
>     uint x = 0xFFFFFFFF;
>     auto y = x + 2;
> 
> what type is y?
> 
> These things obviously need clearly defined rules. Currently the rules
> seem to be, if in doubt, use int. I don't know if that's necessarily
> correct in all cases.

I think this is all covered by polysemous types; Andrei in particular has given 
it considerable thought. As soon as they're introduced the problem should 
disappear for D2.

There's actually a fallacy in the page about warnings. They are not optional.
You can only use -w if the all of the libraries you are using support 
compilation with -w. Therefore, library developers are under considerable 
pressure to provide code which compiles with -w.
And therefore, library developers cannot use bitwise | & ^ operations on 
anything other than an int. ( |=, &=, ^= don't generate the warning, so they're OK).