There's a lot of detail and intricacy here (in that you could likely architect a design that didn't really rely on the sort of hierarchy you describe at all), b

There's a lot of detail and intricacy here (in that you could likely architect a design that didn't really rely on the sort of hierarchy you describe at all), but generally if you wanted something similar to [single] inheritance you could implement std::ops::Deref for the child types. That doesn't necessary cover things like virtual methods, but those could be implemented simply as boxed functions that child instances assign on creation.