ref: e494ac5786800ae9d7e71f0677bd008a8bca8c83
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])