ref: c4d762a20c181a1693ec1fa62e696077ef2b98ba
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])