[MacRuby-devel] Void pointers and userData

Hi, I'm wondering if it is possible to use the userData field of NSEvent in MacRuby. I want to add tracking rectangles to a NSView subclass, and store the object that is mouse has entered in the userData field. Something along the lines of: addTrackingRect(rect, owner:self, userData:obj, assumeInside:false) ... def mouseEntered(event) obj = event.userData[0] end However this produces the runtime error: can't convert C/Objective-C value `0x800418240' of type `ƿ_\377' to Ruby object (ArgumentError) Is it possible to set the NSEvent userData field at all in MacRuby? I can work around if not, but the userData field would be more efficient. Thanks, Kevin.