Vector2 hopefully reduced to a POD type. I got this definition of a C++ POD from Wikipedia. A friend says it shouldn't have the functions like Length(), etc. but my compiler seems to allow it, and Wikipedia doesn't say it can't have them. I'm still not sure if this is actually a POD.

vector2.hpp

/* Copyright: (c) Kayne Ruse 2013
 * 
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 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 
 * 3. This notice may not be removed or altered from any source
 * distribution.
*/
#ifndef VECTOR2_HPP_
#define VECTOR2_HPP_

#include <stdexcept>
#include <cmath>

class Vector2 {
public:
//	double x = 0, y = 0;
	double x, y;
//	Vector2() = default;
//	Vector2(double i, double j) {
//		x = i; y = j;
//	}
	double Length() const {
		return sqrt(x*x+y*y);
	}
	double SquaredLength() const {
		return x*x+y*y;
	}

	double operator[](size_t i) {
		if (i >= 2)
			throw(std::domain_error("Out of range"));
		return *(&x+i);
	}

	//Arithmetic operators
	Vector2 operator+(Vector2 v) const {
		Vector2 ret;
		ret.x = x + v.x;
		ret.y = y + v.y;
		return ret;
	}
	Vector2 operator-(Vector2 v) const {
		Vector2 ret;
		ret.x = x - v.x;
		ret.y = y - v.y;
		return ret;
	}
	Vector2 operator*(Vector2 v) const {
		Vector2 ret;
		ret.x = x * v.x;
		ret.y = y * v.y;
		return ret;
	}
	Vector2 operator*(double d) const {
		Vector2 ret;
		ret.x = x * d;
		ret.y = y * d;
		return ret;
	}

	Vector2 operator/(Vector2 v) {
		if (!v.x || !v.y)
			throw(std::domain_error("Divide by zero"));
		Vector2 ret;
		ret.x = x + v.x;
		ret.y = y + v.y;
		return ret;
	}
	Vector2 operator/(double d) {
		if (!d)
			throw(std::domain_error("Divide by zero"));
		Vector2 ret;
		ret.x = x * d;
		ret.y = y * d;
		return ret;
	}

	bool operator==(Vector2 v) { return (x == v.x && y == v.y); }
	bool operator!=(Vector2 v) { return (x != v.x || y != v.y); }

	//member templates
	template<typename T> Vector2 operator+=(T t) { return *this = *this + t; }
	template<typename T> Vector2 operator-=(T t) { return *this = *this - t; }
	template<typename T> Vector2 operator*=(T t) { return *this = *this * t; }
	template<typename T> Vector2 operator/=(T t) { return *this = *this / t; }
	template<typename T> bool operator==(T t) { return (x == t && y == t); }
	template<typename T> bool operator!=(T t) { return (x != t || y != t); }
};

//non-member templates
template<typename T> Vector2 operator+(T t, Vector2 v) { return v + t; }
template<typename T> Vector2 operator-(T t, Vector2 v) { return v - t; }
template<typename T> Vector2 operator*(T t, Vector2 v) { return v * t; }
template<typename T> Vector2 operator/(T t, Vector2 v) { return v / t; }

template<typename T> bool operator==(T t, Vector2 v) { return v == t; }
template<typename T> bool operator!=(T t, Vector2 v) { return v != t; }

#endif