testsuite: Assert that testsuite ways are known
[ghc.git] / testsuite / tests / typecheck / should_compile / tc195.hs
1 {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies,
2 FlexibleInstances, TypeSynonymInstances #-}
3
4 -- This one made GHC 6.4 loop because Unify.unify
5 -- didn't deal correctly with unifying
6 -- a :=: Foo a
7 -- where
8 -- type Foo a = a
9
10 module ShouldSucceed where
11
12 newtype PRef a = PRef a
13 type Drop1 a = a
14 class Ref a r | a -> r where readRef :: a -> r
15 instance Ref (PRef a) (Drop1 a) where readRef (PRef v) = v
16
17
18