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Код

#include <iostream>

class StarshipLevel1
{
    public:
    void func() { std::cout << "starshipLevel1" << std::endl; }
    virtual void collideWith(AsteroidLevel1* asteroid) { asteroid->collideWith(this); }
};

class StarshipLevel2 : public StarshipLevel1
{
    public:
    void func() { std::cout << "starshipLevel2" << std::endl; }
    virtual void collideWith(AsteroidLevel1* asteroid) { asteroid->collideWith(this); }
};

class AsteroidLevel1
{
    public:
    virtual void collideWith(StarshipLevel1* theStarship) { std::cout << "AsteroidLevel1 collide with -- "; theStarship->func(); }
    virtual void collideWith(StarshipLevel2* theStarship) { std::cout << "AsteroidLevel1 collide with -- "; theStarship->func(); }
};

class AsteroidLevel2 : public AsteroidLevel1
{
    public:
    virtual void collideWith(StarshipLevel1* theStarship) { std::cout << "AsteroidLevel2 collide with -- "; theStarship->func(); }
    virtual void collideWith(StarshipLevel2* theStarship) { std::cout << "AsteroidLevel2 collide with -- "; theStarship->func(); }
};

int main(int argc, char** argv)
{
    StarshipLevel1 theStarshipLevel1;
    StarshipLevel2 theStarshipLevel2;
    
    AsteroidLevel1 theAsteroidLevel1;
    //without using any dynamic dispatch
//     theAsteroidLevel1.collideWith(&theStarshipLevel1);
//     theAsteroidLevel1.collideWith(&theStarshipLevel2);
    
    AsteroidLevel2 theAsteroidLevel2;
    //without using any dynamic dispatch
//     theAsteroidLevel2.collideWith(&theStarshipLevel1);
//     theAsteroidLevel2.collideWith(&theStarshipLevel2);
    
    AsteroidLevel1* pAsteroidLevel1 = &theAsteroidLevel1;
    //using dynamic dispatch
//     pAsteroidLevel1->collideWith(&theStarshipLevel1);
//     pAsteroidLevel1->collideWith(&theStarshipLevel2);
    
    pAsteroidLevel1 = &theAsteroidLevel2;
    //using dynamic dispatch
//     pAsteroidLevel1->collideWith(&theStarshipLevel1);
//     pAsteroidLevel1->collideWith(&theStarshipLevel2);
    
    StarshipLevel1* pStarshipLevel1 = &theStarshipLevel2;
    std::cout << "\n";
//     theAsteroidLevel1.collideWith(&theStarshipLevel1);
//     theAsteroidLevel1.collideWith(pStarshipLevel1);
    std::cout << "\n";
//     theAsteroidLevel2.collideWith(&theStarshipLevel1);
//     theAsteroidLevel2.collideWith(pStarshipLevel1);
    
    //pAsteroidLevel1->collideWith(&theStarshipLevel1);
    //pAsteroidLevel1->collideWith(pStarshipLevel1);
    
    //Double dispatch
    pStarshipLevel1->collideWith(theAsteroidLevel1);
    pStarshipLevel1->collideWith(theAsteroidLevel2);
    pStarshipLevel1->collideWith(pAsteroidLevel1);
}