unsigned policy

[Andrei Alexandrescu (See Website For Email)]

Bruno Medeiros wrote:
> Andrei Alexandrescu (See Website For Email) wrote:
>> Henning Hasemann wrote:
>>> I know this is a more general questions as it applies to C and C++ as 
>>> well,
>>> but somewhere I have to ask and actually D is what Im coding in:
>>>
>>> Should one try to use uint in favor of int whenever one knows for 
>>> sure the value
>>> wont be negative? That whould be a bit more expressive but on the 
>>> other hand
>>> sometimes leads to type problems.
>>> For example, when having things like this:
>>>
>>> T min(T)(T a, T b) {
>>>   return a < b ? a : b;
>>> }
>>>
>>> Here you whould need to ensure to cast values so they share a common 
>>> type.
>>>
>>> How do you code? Do you use uint whenever it suitable reflects the 
>>> data to
>>> store (eg a x-y-position on the screen) or only when necessary?
>>
>> Current D botches quite a few of the arithmetic conversions. Basically 
>> all conversions that may lose value, meaning, or precision should not 
>> be allowed implicitly. Walter is willing to fix D in accordance to 
>> that rule, which would yield an implicit conversion graph as shown in:
>>
>> http://erdani.org/d-implicit-conversions.pdf
>>
> 
> By the way, do you think bool should be implicitely convertible to a
> numeric type? Such that this preciousness is allowed in D:
> 
>   if( true == 2 ) writeln("THEN");
> 
> and the "then" clause is not executed.

I don't like it. I couldn't convince Walter.

Andrei