C# Vec3 struct

        struct Vec3
        {
            public double x, y, z;
            public Vec3(double x_, double y_, double z_)
            {
                x = x_;
                y = y_;
                z = z_;
            }
            public static Vec3 operator +(Vec3 v1, Vec3 v2){
                return new Vec3(v1.x + v2.x, v1.y + v2.y, v1.z + v2.z);
            }
            public static Vec3 operator -(Vec3 v1, Vec3 v2)
            {
                return new Vec3(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z);
            }
            public static Vec3 operator *(Vec3 v, double f)
            {
                return new Vec3(v.x * f, v.y * f, v.z * f);
            }
            public static Vec3 operator /(Vec3 v, double f)
            {
                return v * (1 / f);
            }
            public static double operator %(Vec3 v1, Vec3 v2)
            {
                return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z;
            }
            public static Vec3 operator ^(Vec3 v1, Vec3 v2)
            {
                return new Vec3(v1.y * v2.z - v1.z * v2.y, v1.z * v2.x - v1.x * v2.z, v1.x * v2.y - v1.y * v2.x);
            }
            public double len()
            {
                return Math.Sqrt(this % this);
            }
            public static Vec3 operator !(Vec3 v)
            {
                return v / v.len();
            }
            public override string ToString()
            {
                return String.Format("{0}{1}, {2}, {3}{4}", "{", x, y, z, "}");
            }
        }