template<class Evt>
class Multicast{
public:
	void addObserver(Observer<Evt>&& obs){
		observers.push_back(std::move(obs));
	}

	void broadcast(Evt event){
		for ( auto& obs : observers ){
			obs.observe(event);
		}
	}
private:
	std::vector< Observer<Evt> > observers;
};