testsuite/tests/typecheck/should_compile/T10335.hs


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{-# LANGUAGE MultiParamTypeClasses, FlexibleInstances, ConstraintKinds #-}

module Foo where

type X a = (Eq a, Show a)

class Eq a => C a b

-- HEAD was unable to find the (Eq a) superclass
-- for a while in March/April 2015
instance X a => C a [b]