testsuite: Assert that testsuite ways are known
[ghc.git] / testsuite / tests / typecheck / should_compile / T10642.hs
1 {-# LANGUAGE TypeFamilies #-}
2 module T10642 where
3
4 import Data.Coerce
5
6 type family F a
7
8 newtype D a = D (F a)
9
10 -- | This works on 7.10.1, but fails on HEAD (20150711)
11 coerceD :: F a -> D a
12 coerceD = coerce