1 files changed, 29 insertions, 0 deletions
diff --git a/testsuite/tests/gadt/rw.hs b/testsuite/tests/gadt/rw.hs
new file mode 100644
index 0000000000..0d0018ac30
--- /dev/null
+++ b/testsuite/tests/gadt/rw.hs
@@ -0,0 +1,29 @@
+{-# LANGUAGE GADTs #-}
+
+module Main where
+
+import Data.IORef
+
+data T a where
+  Li:: Int -> T Int
+  Lb:: Bool -> T Bool
+  La:: a -> T a
+
+writeInt:: T a -> IORef a -> IO ()
+writeInt v ref = case v of
+		   ~(Li x) -> writeIORef ref (1::Int)
+
+readBool:: T a -> IORef a -> IO ()
+readBool v ref = case v of
+		   ~(Lb x) -> 
+		       readIORef ref >>= (print . not)
+
+tt::T a -> IO ()
+tt v = case v of
+         ~(Li x) ->  print "OK"
+
+main = do
+	tt (La undefined)
+	ref <- newIORef undefined
+	writeInt (La undefined) ref
+	readBool (La undefined) ref