1 files changed, 3 insertions, 10 deletions
diff --git a/src/Data/Array/Nested/Shaped/Shape.hs b/src/Data/Array/Nested/Shaped/Shape.hs
index 2a12cce..9d463a9 100644
--- a/src/Data/Array/Nested/Shaped/Shape.hs
+++ b/src/Data/Array/Nested/Shaped/Shape.hs
@@ -1,10 +1,9 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DeriveGeneric #-}
-{-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE ImportQualifiedPost #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE NoStarIsType #-}
@@ -39,7 +38,6 @@ import Data.Monoid (Sum(..))
 import Data.Proxy
 import Data.Type.Equality
 import GHC.Exts (Int(..), Int#, build, quotRemInt#, withDict)
-import GHC.Generics (Generic)
 import GHC.IsList (IsList)
 import GHC.IsList qualified as IsList
 import GHC.TypeLits
@@ -216,7 +214,7 @@ listsPermutePrefix perm sh = listsAppend (listsPermute perm (listsTakeLenPerm pe
 type role IxS nominal representational
 type IxS :: [Nat] -> Type -> Type
 newtype IxS sh i = IxS (ListS sh (Const i))
-  deriving (Eq, Ord, Generic)
+  deriving (Eq, Ord, NFData)
 
 pattern ZIS :: forall sh i. () => sh ~ '[] => IxS sh i
 pattern ZIS = IxS ZS
@@ -258,8 +256,6 @@ instance Foldable (IxS sh) where
   null ZIS = False
   null _ = True
 
-instance NFData i => NFData (IxS sh i)
-
 ixsLength :: IxS sh i -> Int
 ixsLength (IxS l) = listsLength l
 
@@ -332,7 +328,7 @@ ixsToLinear = \sh i -> go sh i 0
 type role ShS nominal
 type ShS :: [Nat] -> Type
 newtype ShS sh = ShS (ShX (MapJust sh) Int)
-  deriving (Generic)
+  deriving (NFData)
 
 instance Eq (ShS sh) where _ == _ = True
 instance Ord (ShS sh) where compare _ _ = EQ
@@ -371,9 +367,6 @@ instance Show (ShS sh) where
   showsPrec d (ShS shx) = showsPrec d shx
 #endif
 
-instance NFData (ShS sh) where
-  rnf (ShS shx) = rnf shx
-
 instance TestEquality ShS where
   testEquality (ShS shx1) (ShS shx2) = case shxEqType shx1 shx2 of
     Nothing -> Nothing