{-# LANGUAGE MultiParamTypeClasses #-} -- Tests top-level ambiguity resolution -- This made a post-6.4 GHC fall over in TcSimplify module ShouldFail where class Foo a instance Foo (a -> b) foo :: Foo a => a -> () foo = undefined class Bar a r -- The same happens if we use fundeps: -- class Bar a r | r -> a bar :: Bar a r => r -> () bar = undefined test = foo bar