Universal way to fit node to box

cocos2d-x C++
1

I want to write way (class is best for me) to fit any node to box (via cocos2d::Size). My attemt:
#pragma once

#include "cocos2d.h"

template <class T = cocos2d::Node> class FittableNode: public T {
	static_assert(std::is_base_of<cocos2d::Node, T>::value, "ResizebleNode can work only with nodes");
	public:
		FittableNode() {};
		virtual void ~FittableNode() {};
		cocos2d::Size fitTo;
		inline void resize() {
			auto contentSize = getContentSize();
			setScale(MIN(fitTo.height/contentSize.height, fitTo.width/contentSize.width));
		};
		
};

But I have no idea how handle create and its variations. Can anyone help me, please?
P.S.: of course, I can use function, but it isn’t conveniently for me.