+
+ wxPoint& operator+=(const wxSize& s) { x += s.GetWidth(); y += s.GetHeight(); return *this; }
+ wxPoint& operator-=(const wxSize& s) { x -= s.GetWidth(); y -= s.GetHeight(); return *this; }
+
+ wxPoint operator+(const wxSize& s) const { return wxPoint(x + s.GetWidth(), y + s.GetHeight()); }
+ wxPoint operator-(const wxSize& s) const { return wxPoint(x - s.GetWidth(), y - s.GetHeight()); }