/// Complex for all the bells and whistles use despatma_visitor::visitor; visitor!( #[ helper_tmpl = {visitor.visit_point(&arc.center);}, no_default, ] dyn Arc, #[ no_default, helper_tmpl = { visitor.visit_point(&rectangle.top_left); visitor.visit_point(&rectangle.bottom_right); }, ] Rectangle, dyn Point, #[no_default] dyn Circle, );