poo_2022_com2

https://stackoverflow.com/questions/28206888/casting-down-polymorphic-pointers

https://stackoverflow.com/questions/1826878/polymorphism-and-array-of-pointers-problem-in-c

https://stackoverflow.com/questions/34172938/polymorphism-c-trying-to-access-member-functions-of-classes-that-are-derived

http://www.cplusplus.com/doc/tutorial/polymorphism/

https://stackoverflow.com/questions/1893688/abstract-class-and-using-array-polymorphically

https://learn.saylor.org/mod/book/view.php?id=33049&chapterid=13128

https://stackoverflow.com/questions/27194911/polymorphism-accessing-derived-class-elements-from-a-base-class-array