blob: 985220c472e5e6a5e241612e903b67b3a29845c5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
{-# LANGUAGE TypeFamilies, PolyKinds, DataKinds, GADTs, FlexibleInstances #-}
module T14045a where
import Data.Kind
class C (a :: k) where
data S (a :: k)
-- This used to fail with the mysterious error
-- Type indexes must match class instance head
-- Expected: S z
-- Actual: S a
-- But now it is fine
instance C (z :: Bool) where
data S :: Bool -> Type where
SF :: S False
ST :: S True
|
