1 files changed, 23 insertions, 0 deletions
diff --git a/testsuite/tests/ffi/should_compile/ffi-deriv1.hs b/testsuite/tests/ffi/should_compile/ffi-deriv1.hs
new file mode 100644
index 0000000000..94d0df2fa4
--- /dev/null
+++ b/testsuite/tests/ffi/should_compile/ffi-deriv1.hs
@@ -0,0 +1,23 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+-- Tests newtype unwrapping for the IO monad itself
+-- Notice the RenderM monad, which is used in the
+-- type of the callback function
+
+module ShouldCompile where
+
+import Foreign.Ptr
+newtype RenderM a = RenderM (IO a) deriving (Functor, Monad)
+
+type RenderCallback = Int -> Int -> RenderM ()
+
+foreign import ccall duma_onRender :: FunPtr RenderCallback -> RenderM ()
+
+foreign import ccall "wrapper" mkRenderCallback
+     :: RenderCallback -> RenderM (FunPtr RenderCallback)
+
+onRender :: RenderCallback -> RenderM ()
+onRender f = mkRenderCallback f >>= duma_onRender
+
+
+