base: Remove `Monad(fail)` method and reexport `MonadFail(fail)` instead
[ghc.git] / testsuite / tests / wcompat-warnings / Template.hs
1 {-# LANGUAGE KindSignatures #-}
2
3 module WCompatWarningsOnOff where
4
5 import qualified Data.Semigroup as Semi
6
7 (<>) = undefined -- Semigroup warnings
8
9 -- -fwarn-noncanonical-monoid-instances
10 newtype S = S Int
11
12 instance Semi.Semigroup S where
13 (<>) = mappend
14
15 instance Monoid S where
16 S a `mappend` S b = S (a+b)
17 mempty = S 0
18
19 -- -fwarn-star-is-type
20 b :: (Bool :: *)
21 b = True