///Gives back the bottom right corner (if the bounding box is empty, then the return value is not defined) 

       xy<T> bottomRight() const {

 	return xy<T>(top_right.x,bottom_left.y);

       };

       ///Gives back the top left corner (if the bounding box is empty, then the return value is not defined) 

       xy<T> topLeft() const {

 	return xy<T>(bottom_left.x,top_right.y);

       };

       ///Gives back the bottom of the box (if the bounding box is empty, then the return value is not defined) 

       T bottom() const {

 	return bottom_left.y;

       };

       ///Gives back the top of the box (if the bounding box is empty, then the return value is not defined) 

       T top() const {

 	return top_right.y;

       };

       ///Gives back the left side of the box (if the bounding box is empty, then the return value is not defined) 

       T left() const {

 	return bottom_left.x;

       };

       ///Gives back the right side of the box (if the bounding box is empty, then the return value is not defined) 

       T right() const {

 	return top_right.x;

       };