template<typename ... _Ty>

class ListG;

template<typename ... _Ty>

class ListH;

template<typename... _Ty>

class BN {

public:

? ? constexpr static void out() {

? ? ? ? (std::cout << ... << typeid(_Ty).name());

? ? }

};

template<typename... _Ty>

class BN<ListG<_Ty...>> :public BN<_Ty...> {};

template<typename... _Ty>

class BN<ListH<_Ty...>> :public BN<ListG<_Ty...>> {};

//BN 重載 根據(jù)輸入自動(dòng)匹配?