Is there any alternative to friendship in the following scenario?
I have a Window class which represents an UI window. Also, a WindowManager class, implemented as a singleton, manages all window objects in my application (renders the UI, dispatches events, etc.)
The WindowManager will have a public interface consisting of only its singleton instancing method and functions to render the UI and to dispatch an UI event.
I would also like Window objects to register with the WindowManager during construction and to de-register during destruction. The WindowManager::register and WindowManager::deregister methods will be either private or protected, because I do not want clients (other than Window objects) to be able use this interface.
Is there a method to avoid friendship between Window and WindowManager in this case? Perhaps a totally different way to achieve similar results?
