2014 and 2015: I do not recommend that you spend time on this exercise...
Introduce two variants of persons, as introduced in the C program on the accompanying slide.
- Persons who live at a specific location.
- Homeless persons, without location and without any id.
Introduce two different person types, and a union that allows us to represent either a 'person with a home address' or a 'homeless person'.
You can read about unions in The C++ Prog. Lang. (3. edition) section C.8.2.
