added pointer_eq;

--- a/src/Pure/ML-Systems/mosml.ML	Mon Jun 20 22:14:15 2005 +0200
+++ b/src/Pure/ML-Systems/mosml.ML	Mon Jun 20 22:14:17 2005 +0200
@@ -19,6 +19,10 @@
 
 (** ML system related **)
 
+(*proper implementation available?*)
+fun pointer_eq (x:''a, y) = false;
+
+
 (* Poly/ML emulation *)
 
 load "Bool";

--- a/src/Pure/ML-Systems/polyml.ML	Mon Jun 20 22:14:15 2005 +0200
+++ b/src/Pure/ML-Systems/polyml.ML	Mon Jun 20 22:14:17 2005 +0200
@@ -21,6 +21,11 @@
 fun unless_cygwin f x = if not cygwin_platform then f x else ();
 
 
+(* low-level pointer equality *)
+
+fun pointer_eq (x:''a, y) = Address.wordEq (x, y);
+
+
 (* old Poly/ML emulation *)
 
 local

--- a/src/Pure/ML-Systems/smlnj.ML	Mon Jun 20 22:14:15 2005 +0200
+++ b/src/Pure/ML-Systems/smlnj.ML	Mon Jun 20 22:14:17 2005 +0200
@@ -11,6 +11,12 @@
 
 (** ML system related **)
 
+(* low-level pointer equality *)
+
+(*proper implementation available?*)
+fun pointer_eq (x:''a, y) = false;
+
+
 (* restore old-style character / string functions *)
 
 val ord     = SML90.ord;