virtual

#include <windows.h>
#include <iostream>
#include <stdio.h>
#include <vector>

using namespace std;

class Tier
{
public:
    Tier(){}
    virtual ~Tier(){}
    virtual void essen(){ cout << "Das Tier frisst!" << endl; }
    void Hunger()
    {
        for(vector<Tier*>::iterator it = Tiere.begin(); it != Tiere.end(); it ++)
        {
            Tier *X = *it;
            X->essen();
        }
    }
    void AddTierObj(Tier* Obj)
    {
        Tiere.push_back(Obj);
    }
private:
    vector<Tier*> Tiere;
};

class Katze: public Tier
{
public:
    Katze(){}
    ~Katze(){}
    void essen() { cout << "Katze frisst" << endl; }
};

class Hund : public Tier
{
public:
    Hund()  {}
    ~Hund(){}

    void essen() { cout << "Hund frisst!" << endl; }
};

void Fressen(Tier* x)
{
    x->Hunger();
}
int main()
{
    Hund H;
    Katze K;
    Tier T;

    T.AddTierObj(&H);
    T.AddTierObj(&K);

    T.Hunger();
    T.Hunger();

    getchar();
    return 1;
}