/*
 * subtuple: allow matlab-like taking of only the first n return values, like
 *
 * std::tuple<A, B, C, D> f();
 * A a;
 * B b;
 * tiex(a, b) = f();
 *
 * Evan Herbst
 * 9 / 2 / 09
 */

#ifndef EX_SUBTUPLE_H
#define EX_SUBTUPLE_H

#include <tuple>

template <typename... Ts> class subtuple;

template <typename T1> class subtuple<T1>
{
	public:

		subtuple(T1& a1) : data(a1)
		{}
		template <typename... Ts2>
		subtuple(const std::tuple<Ts2...>& t)
		{
			std::get<0>(data) = std::get<0>(t);
		}
		template <typename... Ts2>
		subtuple(std::tuple<Ts2...>&& t)
		{
			std::get<0>(data) = std::move(std::get<0>(t));
		}

		template <typename... Ts2>
		void operator = (const std::tuple<Ts2...>& t)
		{
			std::get<0>(data) = std::get<0>(t);
		}

		template <typename... Ts2>
		void operator = (std::tuple<Ts2...>&& t)
		{
			std::get<0>(data) = std::move(std::get<0>(t));
		}

	private:

		std::tuple<T1&> data;
};

template <typename T1, typename T2> class subtuple<T1, T2>
{
	public:

		subtuple(T1& a1, T2& a2) : data(a1, a2)
		{}
		template <typename... Ts2>
		subtuple(const std::tuple<Ts2...>& t)
		{
			std::get<0>(data) = std::get<0>(t);
			std::get<1>(data) = std::get<1>(t);
		}
		template <typename... Ts2>
		subtuple(std::tuple<Ts2...>&& t)
		{
			std::get<0>(data) = std::move(std::get<0>(t));
			std::get<1>(data) = std::move(std::get<1>(t));
		}

		template <typename... Ts2>
		void operator = (const std::tuple<Ts2...>& t)
		{
			std::get<0>(data) = std::get<0>(t);
			std::get<1>(data) = std::get<1>(t);
		}

		template <typename... Ts2>
		void operator = (std::tuple<Ts2...>&& t)
		{
			std::get<0>(data) = std::move(std::get<0>(t));
			std::get<1>(data) = std::move(std::get<1>(t));
		}

	private:

		std::tuple<T1&, T2&> data;
};

template <typename... Ts>
subtuple<Ts...> tiex(Ts&... args)
{
	return subtuple<Ts...>(args...);
}

#endif //EX_SUBTUPLE_H