[Haskell-cafe] RankNTypes question

[Nikolay Amiantov]

Hi Cafe,

I can't find how can I do this:

{-# LANGUAGE RankNTypes #-}

example :: forall a. (forall b. b) -> a
example = undefined

The first `forall` is for cosmetic reasons. If I understand correctly 
this is a safe and legit function (please correct me if I'm wrong!). I 
thought that I can just define `example = id` and GHC would do the rest, 
but alas, that didn't happen.

Thanks!

-- 
Nikolay.