Comment créer un tableau de classes en C ++?

#include <cstdlib>
#include <ctime>
#include <iostream>
#include <map>
#include <vector>
#include <memory>

using namespace std;




// interface
class Base
{
public:
    virtual ~Base() { }
    virtual int getClassId() = 0;
};


// class A relizes interface Base, has ID == 1 (is used in automatic registration to factory)
class A : public Base
{
public:
    const static int ID = 1;
    static Base* CreateInstance()
    {
        return new A();
    }

    virtual int getClassId()
    {
        return ID;
    }

    virtual ~A() { }
};


// class B relizes interface Base, has ID == 2 (is used in automatic registration to factory)
class B : public Base
{
public:
    const static int ID = 2;
    static Base* CreateInstance()
    {
        return new B();
    }

    virtual int getClassId()
    {
        return ID;
    }

    virtual ~B() { }
};



// this is the objects factory, with registration only (unregister s not allowed)
class ObjectFactory
{
    ObjectFactory() { }
    ObjectFactory(ObjectFactory&) { }
public:
    virtual ~ObjectFactory() { }
    static ObjectFactory& instance()
    {
        static ObjectFactory objectFactory;

        return objectFactory;
    }

    typedef Base* (*Creator) ();

    void registerCreator(int id, Creator creator)
    {
        registry[id] = creator;
    }

    Base* CreateById(int id)
    {
        return registry[id]();
    }

private:
    map<int, Creator> registry;
};


// this template class is used for automatic registration of object's creators
template <class T>
struct RegisterToFactory
{
    RegisterToFactory(ObjectFactory& factory)
    {
        factory.registerCreator(T::ID, &T::CreateInstance);
    }
};


namespace
{
    // automaticaly register creators for each class
    RegisterToFactory<A> autoregisterACreator(ObjectFactory::instance());
    RegisterToFactory<B> autoregisterBCreator(ObjectFactory::instance());
}




// lets this this solution
int main(int argc, char *argv[])
{
    vector<int> ids;

    ids.push_back(static_cast<int>(A::ID));
    ids.push_back(static_cast<int>(B::ID));

    srand(time(0));

    for (int i = 0; i < 20; ++i)
    {
        int randomClasssId = ids[rand() % ids.size()];
        auto_ptr<Base> testObject(ObjectFactory::instance().CreateById(randomClasssId));
        cout << "Object of classId = " << testObject->getClassId() << " has been produced by factory." << endl;
    }


    system("PAUSE");
    return EXIT_SUCCESS;
}