testsuite/tests/roles/should_compile/Roles13.hs


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{-# LANGUAGE TypeFamilies, GeneralizedNewtypeDeriving,
             MultiParamTypeClasses, FunctionalDependencies #-}

-- tests axiom roles

module Roles13 where

newtype Age = MkAge Int
newtype Wrap a = MkWrap a

convert :: Wrap Age -> Int
convert (MkWrap (MkAge i)) = i