#include <iostream>

template <class T>
class SubSys {
 public:
    virtual void Handle(T*) {
        std::cout << "Event recieved but not handled." << std::endl;
    };
};

class Event {
 public:
    virtual void dispatch() = 0;
};

template <class T>
class BaseEvent : public Event
{
 public:
    void addListener(SubSys<T>* ss_ptr) { ssptr = ss_ptr; };
    virtual void dispatch()  {
        ssptr->Handle(dynamic_cast<T*>(this));
    }
    static SubSys<T>* ssptr;
};

template <class T>
SubSys<T>* BaseEvent<T>::ssptr;

/*------------------------------------*/

class SubEvent : public BaseEvent<SubEvent> {
};

class StupidEvent : public BaseEvent<StupidEvent> {
};


class SubSystem : public SubSys<SubEvent>, public SubSys<StupidEvent> {
 public:
   void Handle(SubEvent* e) { std::cout << " Got a subevent" << std::endl; }
   void Handle(StupidEvent* e) { std::cout << " Got a stupidevent" << std::endl; }
};


int main() {
    StupidEvent* a = new StupidEvent;
    SubEvent* b = new SubEvent;

    SubSystem *ss = new SubSystem;
    b->addListener(ss);
    a->addListener(ss);
    delete b;
    delete a;

    Event* d = new StupidEvent;
    Event* c = new SubEvent;

    c->dispatch();
    d->dispatch();

    return 0;
};