1 files changed, 19 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc056.hs b/testsuite/tests/typecheck/should_compile/tc056.hs
new file mode 100644
index 0000000000..64d7138571
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/tc056.hs
@@ -0,0 +1,19 @@
+-- !!! Duplicate class assertion warning
+
+-- ghc 6.6 now warns about duplicate class assertions,
+
+module ShouldSucceed where
+
+class Eq' a where
+ doubleeq :: a -> a -> Bool
+
+class (Eq' a) => Ord' a where
+ lt :: a -> a -> Bool
+
+instance Eq' Int where
+ doubleeq x y = True
+
+instance (Eq' a, Eq' a) => Eq' [a] where
+ doubleeq x y = True
+
+f x y = doubleeq x [1]