-- and used an underscore pattern, the following equality wouldn't hold:
-- x `deepseq` () = x `seq` () = _|_
-- where x = undefined :: T
- -- with T being
() or any unit-shaped type with a DeepSeq instance.
+ -- with T being unit-shaped type with a DeepSeq instance.
instance DeepSeq a => GDeepSeq (K1 i a) where