Conditional Pure?

[bearophile]

%u:

> Oh, but that's not what I meant! I meant something like this:
> 
>   int call(TFn)(TFn fn) pure(isPure!(TFn))
>      if (isCallable!(TFn))
>   {
>      return fn(5);
>   }
> 
> This way we specify purity based on a static boolean.

I see. I'd like a more general-purpose solution, something that works with nothrow too and other future attributes too. So I have suggested:
http://d.puremagic.com/issues/show_bug.cgi?id=5125

Bye,
bearophile