public static bool Intersects(this Index2 index, Rectangle rect) => rect.Intersects(index);
public Index3(Index2 pos) : this(pos, 0) { }
public static bool Intersects(this Rectangle rect, Index2 index) => rect.Intersects(new Rectangle(index.X, index.Y, 1, 1));
public Index3(Index2 pos, int z) : this(pos.X, pos.Y, z) { }