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{-# LANGUAGE PolyKinds, FlexibleInstances, ScopedTypeVariables,
UndecidableInstances #-}
{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
module PolyInstances where
import GHC.Exts
import Data.Proxy
class C (a :: k)
instance (C a, C b) => C (a b)
data Dict :: Constraint -> *
instance C Dict
foo :: C p => proxy p -> ()
foo = undefined
bar :: forall (p :: Constraint) proxy. C p => proxy p -> ()
bar _ = foo (Proxy :: Proxy (Dict p))
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