Define Semigroup Void instance on base-4.8.0.0 and later

ekmett · Apr 6, 2015 · c29113e · c29113e
1 parent 11b52b6
commit c29113e
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/src/Data/Semigroup.hs b/src/Data/Semigroup.hs
@@ -89,6 +89,7 @@ import Prelude hiding (foldr1)
 
 #if MIN_VERSION_base(4,8,0)
 import Data.Bifunctor
+import Data.Void
 #else
 import Data.Monoid (Monoid(..))
 import Data.Foldable
@@ -321,6 +322,12 @@ instance Semigroup (Monoid.Last a) where
   times1p _ a = a
 #endif
 
+#if MIN_VERSION_base(4,8,0)
+instance Semigroup Void where
+  a <> _ = a
+  times1p _ a = a
+#endif
+
 instance Semigroup (NonEmpty a) where
   (a :| as) <> ~(b :| bs) = a :| (as ++ b : bs)