sclass Pt is Comparable<Pt>, IDoublePt {

  int x, y;

  *() {}

  *(Point p) {

    x = p.x;

    y = p.y;

  }

  *(int *x, int *y) {}

  Point getPoint() {

    ret new Point(x, y);

  }

  public bool equals(O o) {

    ret o instanceof Pt && x == o/Pt.x && y == o/Pt.y;

  }

  public int hashCode() {

    ret boostHashCombine(x, y);

  }

  // compare in scan order

  public int compareTo(Pt p) {

    if (y != p.y) ret cmp(y, p.y);

    ret cmp(x, p.x);

  }

  public S toString() {

    ret x + ", " + y;

  }

  double length() { ret sqrt(x*x+y*y); }

  public Pt minus(Pt p) { ret ptMinus(this, p); }

  public double x_double() { ret x; }

  public double y_double() { ret y; }

}