empty-foralls2.hs

{-# LANGUAGE GADTs #-}
{-# LANGUAGE RankNTypes #-}
-- Empty foralls are handled correctly in different situations.

data D = forall. D Int

data G where
  G :: forall. Int -> G

f :: forall. a -> a
f x = x

type family T x where
  forall. T x = x

{-# RULES
  "r"
  forall. r a = ()
#-}