ref: c6e8e33dc429495ac8a20e9a5d40f4ea2ceb787a
dir: /tests/DfltSig.hs/
module DfltSig where class Def a where def :: a default def :: Enum a => a def = toEnum 0 instance Def Int instance Def Char instance Def [a] where def = [] main :: IO () main = print (def::Int, def::Char,def::[Bool])