empty-forall-four-out.hs

-- 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 =
        ()
    #-}