Cocoa:NSWindow(Custom Categories) with instance variables (Multiple Inheritance)
Here is the code update to my prior post which includes the changes to have a small std::map manage the private instance data.
I've added a third 'case'. I have one IB window which is a custom class derived from NSWindow, another NSPanel derived class, and a third NSWindow instance which is acted on by controller. All three equally adept at responding to methods from NSWindow(DataGory) with private instance data.
Since you're using accessor functions for all your instance data anyway (right!) it doesn't really matter that you can't access the virtual self directly, now does it?