Demo

test.cc

/*
  Source: http://szymonsiarkiewicz.pl/poradniki/goto/kolizje/kolizje-w-grach-2d/
  Author: Szymon "shead" Siarkiewicz
*/

/* commandline:
$ g++ --version
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ g++ test.cc -o test
$ ./test
$ echo $?
3

*/

class Vector2
{
public:
    int x;
    int y;
};


class Box
{
public:
    Vector2 position;                   // pozycja (x,y) krawędzi prostokąta/kwadratu

    unsigned int width;                 // szerokość
    unsigned int height;                    // wysokość
};

int main()
{
  Box box;
  box.position.x = 3;
  return box.position.x;
}