1 files changed, 41 insertions, 0 deletions
diff --git a/testsuite/tests/deriving/should_run/T10447.hs b/testsuite/tests/deriving/should_run/T10447.hs
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index 0000000000..e91ce98f64
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+++ b/testsuite/tests/deriving/should_run/T10447.hs
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+{-# LANGUAGE DeriveFoldable, GADTs, StandaloneDeriving #-}
+module Main where
+
+class (a ~ Int) => Foo a
+instance Foo Int
+
+data A a where
+  A1 :: Ord a            => a        -> A a
+  A2 ::                     Int      -> A Int
+  A3 :: b ~ Int          => b        -> A Int
+  A4 :: a ~ Int          => Int      -> A a
+  A5 :: a ~ Int          => a        -> A a
+  A6 :: (a ~ b, b ~ Int) => Int -> b -> A a
+  A7 :: Foo a            => Int -> a -> A a
+
+deriving instance Foldable A
+
+data HK f a where
+  HK1 :: f a -> HK f (f a)
+  HK2 :: f a -> HK f a
+
+deriving instance Foldable f => Foldable (HK f)
+
+one :: Int
+one = 1
+
+main :: IO ()
+main = do
+  mapM_ (print . foldr (+) one)
+    [ A1 one
+    , A2 one
+    , A3 one
+    , A4 one
+    , A5 one
+    , A6 one one
+    , A7 one one
+    ]
+  mapM_ (print . foldr mappend Nothing)
+    [ HK1 (Just "Hello")
+    , HK2 (Just (Just "World"))
+    ]