Fix #14729 by making the normaliser homogeneous
[ghc.git] / testsuite / tests / typecheck / should_compile / T15549a.hs
1 {-# LANGUAGE EmptyCase #-}
2 {-# LANGUAGE ScopedTypeVariables #-}
3 {-# LANGUAGE TypeFamilies #-}
4 {-# LANGUAGE PolyKinds #-}
5 {-# LANGUAGE DataKinds #-}
6 module T15549a where
7
8 import Data.Proxy
9 import Data.Void
10
11 data family Sing (a :: k)
12 data instance Sing (z :: Void)
13
14 type family Rep a
15 class SGeneric a where
16 sTo :: forall (r :: Rep a). Sing r -> Proxy a
17
18 type instance Rep Void = Void
19 instance SGeneric Void where
20 sTo x = case x of