impure

[Dom DiSc]

I'm creating a library that is completely pure, but it doesn't 
compile with pure: at the top because of one impure unittest 
(which uses random to  test some things only probabilistic)!

So do I really need to declare every function pure individually 
because of a test?!?

Can we please have a @impure attribute?
And by the way also @throws and @gc?
That would make live so much easier...