toople

gistfile1.txt

#include <tuple>
#include <iostream>

template <size_t CUR, size_t END>
struct ForEachIter_t {
	template <typename CALLABLE, typename...TYPES>
	static void Do(std::tuple<TYPES...>& tpl, CALLABLE&& func) {
		auto& tplItem = std::get<CUR>(tpl);
		func(tplItem);
		ForEachIter_t<CUR + 1, END>::Do(tpl, func);
	};
};

template <size_t CUR>
struct ForEachIter_t<CUR, CUR> {
	template <typename CALLABLE, typename...TYPES>
	static void Do(std::tuple<TYPES...>&, CALLABLE&&) {};
};

template <typename CALLABLE, typename...TYPES>
void ForEach(std::tuple<TYPES...>& tpl, CALLABLE&& func) {
	constexpr size_t tplSize = std::tuple_size<std::tuple<TYPES...>>::value;
	ForEachIter_t<0, tplSize>::Do(tpl, func);
}

template<size_t DST_BEG, size_t CUR, size_t END>
struct SumIter_t {
	template<typename...T1, typename...T2>
	static void Do(const std::tuple<T2...>& src, std::tuple<T1...>& dst) {
		std::get<DST_BEG + CUR>(dst) = std::get<CUR>(src);
		SumIter_t<DST_BEG, CUR + 1, END>::Do(src, dst);
	}
};

template<size_t DST_BEG, size_t CUR>
struct SumIter_t<DST_BEG, CUR, CUR> {
	template<typename...T1, typename...T2>
	static void Do(const std::tuple<T2...>& src, std::tuple<T1...>& dst) {}
};


template <typename...T1, typename...T2>
std::tuple<T1..., T2...> ConcatTuple(const std::tuple<T1...>& tpl1, const std::tuple<T2...>& tpl2) {
	std::tuple<T1..., T2...> ret;

	SumIter_t<0, 0, sizeof...(T1)>::Do(tpl1, ret);
	SumIter_t<sizeof...(T1), 0, sizeof...(T2)>::Do(tpl2, ret);
	return ret;
}

void main() {
	auto tpl1 = std::make_tuple(1, 4.4, 3u, 2.2f);
	auto tpl2 = std::make_tuple(4, 3.3f, 2u, 1.1);
	auto ret = ConcatTuple(tpl1, tpl2);

	ForEach(ret, [] (const auto& itm) {
		std::cout << itm << std::endl;;
	});
}