arithmetic.h++

#pragma once

struct adder {
	template <typename Tl, typename Tr>
	auto operator()( Tl&& left, Tr&& right )
		-> decltype( left + right ) {
		return left + right;
	}
};

struct subtracter {
	template <typename Tl, typename Tr>
	auto operator()( Tl&& left, Tr&& right )
		-> decltype( left - right ) {
		return left - right;
	}
};

struct multiplier {
	template <typename Tl, typename Tr>
	auto operator()( Tl&& left, Tr&& right )
		-> decltype( left * right ) {
		return left * right;
	}
};

struct divider {
	template <typename Tl, typename Tr>
	auto operator()( Tl&& left, Tr&& right )
		-> decltype( left / right ) {
		return left / right;
	}
};

struct modulus {
	template <typename Tl, typename Tr>
	auto operator()( Tl&& left, Tr&& right )
		-> decltype( left % right ) {
		return left % right;
	}
};