OOP without the heap

oopnoheap.cpp

#include <iostream>


class Mammal
{
public:
    Mammal();
    ~Mammal();
};


class Dog : public Mammal
{
public:
    Dog();
    ~Dog();
};

class Cat : public Mammal
{
public:
    Cat();
    ~Cat();
};

class Zoo
{
public:
    Zoo();
    ~Zoo();

    void Add(Dog* d);
    void Add(Cat* c);

private:
    Dog* dogs[10];
    Cat* cats[10];
};

Zoo zoos[10];
Dog dogs[10];
Cat cats[10];

int main()
{
    Zoo* zoo = &(zoos[0]);
    Dog* snoopy = &(dogs[0]);
    Cat* savannah = &(cats[0]);

    zoo->Add(snoopy);
}