poorly::midpoint, poor man's std::midpoint that avoids overflow caveat

Poorly_Midpoint.h

// Taken from Kevlin Henny video https://www.youtube.com/watch?v=YoaZzIZFErI
// poorly::midpoint is poor man's std::midpoint that avoids overflow caveat

namespace poorly
{
	struct autoswap_range {};

	template<typename T, typename T2 = T>
	inline constexpr T midpoint(const T& low, const T2& high) noexcept
	{
		return low + ((high - low) / 2);
	}

	template<typename T, typename T2 = T>
	inline constexpr T midpoint(const T& low, const T2& high, const autoswap_range&) noexcept
	{
		return poorly::midpoint((low < high ? low : high), (high < low ? low : high));
	}
};


//Test it out!
constexpr int test()
{
  using namespace poorly;
	
  // Simple cases
	auto midpoint1 = midpoint(5, 10);		    // 7
	auto midpoint2 = midpoint(5, 11);		    // 8
	// Negatives, correct way around
	auto midpoint3 = midpoint(-10, -5);		  //-8
	// Negatives, wrong way around
	auto midpoint4 = midpoint(-5, -10);		  //-7
	auto midpoint5 = midpoint(-5, -10, {}); //-8

	// Equivalent
	auto midpointAutoswap  = midpoint(10, 5, {});
	auto midpointAutoswap2 = midpoint(10, 5, autoswap_range());
}

int main()
{
  return test();
}