]> Hello everbody, Please consider the following: # class virtual x = object method virtual foo : int end class virtual y = object method virtual bar : string end class z = object method foo = 2 method bar = "there" end;; How can I assert that class "z" is supposed to be a subtype of class x and class y? In other words, how can I assert that (some_z : z :> x) and (some_z : z :> y) will always be valid? I tried: # class z = object (self : #x, self : #y) method foo = 2 method bar = "there" end;; Characters 29-30: object (self : #x, self : #y) ^ Syntax error But, it only works for one supertype, e.g.: class z = object (self : #x) (* or (self : #y) *) method foo = 2 method bar = "there" end;; I know that I could just leave it out and everything would work, but I want to specify that z is supposed to be a subtype of both x and y so that, if I screw up the definition of class z, the compiler will give me an error. For example, if I didn't define the method "bar" in class "z", I want to get the error: This class type should be virtual The following methods are undefined : bar Thanks, Brian ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners