Deriving for phantom and empty types
[ghc.git] / testsuite / tests / deriving / should_compile / drv-phantom.hs
1 {-# LANGUAGE RoleAnnotations #-}
2 {-# LANGUAGE DeriveTraversable #-}
3
4 module DrvPhantom where
5 import GHC.Generics (Generic, Generic1)
6 import Data.Data (Data)
7 import Language.Haskell.TH.Syntax (Lift)
8
9 data NotAList a = Nil | NotCons (NotAList a)
10 deriving (Functor, Foldable, Traversable)
11
12 type role NotAList phantom