To help LDC/GDC

[Andrei Alexandrescu]

On 4/9/13 11:42 AM, Dicebot wrote:
> On Tuesday, 9 April 2013 at 15:20:48 UTC, Andrei Alexandrescu wrote:
>>> Not gonna argue latter but former is just wrong.
>>>
>>> struct Test
>>> {
>>> int a;
>>> pure int foo1() // strong pure
>>> {
>>> return 42;
>>> }
>>>
>>> pure int foo2() // weak pure
>>> {
>>> return a++;
>>> }
>>> }
>>>
>>> Signature is the same for both functions.
>>
>> Both are weakly pure.
>>
>> Andrei
>
> And that is even more surprising as foo2 perfectly matches concept of
> pure and can be applied all possible optimizations to. It is weird.

I disagree about it being weird.

> "weak pure" is useful only to implement "strong pure". "strong pure" is
> useful only if it can be statically enforced to provide some guarantees.
> "strong pure" is useless because it shares same annotation with "weak
> pure".

I think it's a great design, very useful and innovative.


Andrei