testsuite/tests/indexed-types/should_compile/T3208a.hs


1
2
3
4
5
6
7
8
9
10
11
12
13
14

{-# LANGUAGE TypeFamilies #-}

module T3208a where
  
class SUBST s where
    type STerm s

class OBJECT o where
    type OTerm o
    apply :: (SUBST s, OTerm o ~ STerm s) => s -> o

fce' f = fce . apply $ f

fce f = fce' f