A rationale for pure nothrow ---> @pure @nothrow (and nothing else changes)

[Lutger]

Don wrote:
...
> 
> I genuinely thought @pure, @nothrow was a no-brainer.
> 
> I really thought the explanation that "we made all attibutes use the @
> form, except those where it was prevented by historical precedent" was
> quite defensible.
> 
> But I was very, very wrong. Looks like the community is giving a massive
> vote for complete unpredictability.
> 
> <Throws hands in air />

Massive? Not everybody in this thread was against these rules and this 
thread is not even massive (yet?)

I like it. Ideally you want to capture the reason why there is some sort 
consensus here with @pure and @nothrow. It's just a bit backwards justifying 
something after the fact and messy, but that's how it is. Better to have a 
weird rule than no rule imho.

This probably also has been talked to death but I can't refrain from asking: 
when hasAttribute will be implemented, will user defined attributes be 
considered or are they definitely off the table for D2?