I have no idea what is wrong with this. Trying to assign a new vector doesn't seem to change the values. Values are only changed using the initial constructor or if manually accessing members.

vector.cpp

#include <math.h>
#include <iostream>

class Vector
{
public:
	float x;
	float y;

    // constructor
	Vector()
	: x(0),y(0)
	{
	}

    Vector(float _x, float _y)
	: x(_x),y(_y)
    {
    }

    // modifying operators
	Vector operator =(const Vector &rhs)
    {
        return Vector(rhs.x, rhs.y);
    }
	Vector operator*=(const Vector &rhs)
    {
        return Vector(x*rhs.x, y*rhs.y);
    }
	Vector operator/=(const Vector &rhs)
    {
        return Vector(x/rhs.x, y/rhs.y);
    }
	Vector operator+=(const Vector &rhs)
    {
        return Vector(x+rhs.x, y+rhs.y);
    }
	Vector operator-=(const Vector &rhs)
    {
        return Vector(x-rhs.x, y-rhs.y);
    }
	Vector operator*=(const float rhs)
    {
        return Vector(x*rhs, y*rhs);
    }
	Vector operator/=(const float rhs)
    {
        return Vector(x*rhs, y*rhs);
    }
	bool operator ==(const Vector &rhs)
	{
		return ((x==rhs.x)&&(y==rhs.y));
	}
	bool operator !=(const Vector &rhs)
	{
		return ((x!=rhs.x)||(y!=rhs.y));
	}
	Vector operator =(const Vector &rhs) const
    {
        return Vector(rhs.x, rhs.y);
    }
	Vector operator -(const Vector &rhs) const
	{
		return Vector(x - rhs.x, y - rhs.y);
	}
	Vector operator +(const Vector &rhs) const
	{
		return Vector(x + rhs.x, y + rhs.y);
	}
	Vector operator*(const float scale) const
    {
        return Vector(x*scale, y*scale);
    }
};

int main(int argc, char** argv)
{
        Vector test(32,64);
        test = Vector(12,0);
        std::cout << "Vector: [" << test.x << "," << test.y << "]" <<std::endl;
        return 0;
}