TMP二分木fold

gistfile1.txt

namespace otmp
{
    template<class list, template<class...>class Func>
	class fold1
	{
		template<std::size_t Begin, std::size_t Len>
		struct impl
			:Func<typename impl<Begin, Len / 2>::type, typename impl<Begin + Len / 2, Len - Len / 2>::type>
		{};
		template<std::size_t Begin>
		struct impl<Begin, 1>
			:at<Begin, list>
		{};
	public:
		using type = typename impl<0, getLength_t<list>::value>::type ;
	};
}