Graham's completely correct. If this is new development, don't do it. Find a better solution. I guarantee there is one.

These types of hierarchies were much more common in the days when templates were not as well supported as they are now. All-encomposing hierarchies were used so that you could create a container class that maintained pointers to a common base class. Think CObject in MFC.

My point is that if what you are working on already has this hierarchy, it may be too expensive to fix at this point, even if it should be fixed.

Jeff