+
+#ifdef __HUGS__
+import Hugs.StablePtr
+#endif
+
+#ifdef __NHC__
+import NHC.FFI
+ ( StablePtr
+ , newStablePtr
+ , deRefStablePtr
+ , freeStablePtr
+ , castStablePtrToPtr
+ , castPtrToStablePtr
+ )
+#endif
+
+-- $cinterface
+--
+-- The following definition is available to C programs inter-operating with
+-- Haskell code when including the header @HsFFI.h@.
+--
+-- > typedef void *HsStablePtr; /* C representation of a StablePtr */
+--
+-- Note that no assumptions may be made about the values representing stable
+-- pointers. In fact, they need not even be valid memory addresses. The only
+-- guarantee provided is that if they are passed back to Haskell land, the
+-- function 'deRefStablePtr' will be able to reconstruct the
+-- Haskell value referred to by the stable pointer.