Class::MethodMaker has a method maker called "object" that declares a slot to be of a particular object type.
Oh, I see. Thanks for the clarification. However, this seems quite orthogonal to Class::Container. One might want to use Class::Container to create the objects with the proper parameters, then use Class::MethodMaker to create interfaces to the objects, possibly using the proxies Class::MethodMaker provides.
It's quite possible that someone would want to use both in the same project, but that doesn't suggest to me that they should be in the same module.