+ void extend (Rect<T> const & other)
+ {
+ x = std::min (x, other.x);
+ y = std::min (y, other.y);
+ width = std::max (x + width, other.x + other.width) - x;
+ height = std::max (y + height, other.y + other.height) - y;
+ }
+
+ bool contains (Position<T> p) const
+ {