testsuite: Assert that testsuite ways are known
[ghc.git] / testsuite / tests / typecheck / should_compile / RepArrow.hs
1 {-# LANGUAGE FlexibleContexts #-}
2
3 module RepArrow where
4
5 import Data.Ord ( Down ) -- convenient "Id" newtype, without its constructor
6 import Data.Coerce
7
8 foo :: Coercible (Down (Int -> Int)) (Int -> Int) => Down (Int -> Int) -> Int -> Int
9 foo = coerce