I currently was using multiple inheritance to define the message classes
that a class supports, but this caused problems when, for example, a
class tested to see if an object supported CMouseMsg. The class in
question supported several mouse messages, but a standard dynamic_cast
returned nullptr for the class, since it didn't directly support it
This is necessary for at least message sending, and probably other
areas, that needs to be able to pass class filtering for message
targets. And I could figure out a clean way to use the built-in RTTI
Paul Gilbert