Test Trac #7641

testsuite/tests/typecheck/should_compile/T7641.hs

+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+module T7641 where
+
+data Foo b = Foo deriving Show
+
+class ToFoo a b where
+    toFoo :: a -> Foo b
+
+instance ToFoo (c -> ()) b where
+    toFoo _ = Foo
+
+baz () = toFoo $ \_ -> ()

testsuite/tests/typecheck/should_compile/all.T

@@ -397,3 +397,4 @@ test('T7408', normal, compile, [''])
 test('UnboxStrictPrimitiveFields', normal, compile, [''])
 test('T7541', normal, compile, [''])
 test('T7562', normal, compile, [''])
+test('T7641', normal, compile, [''])