When apply observer pattern an error occured
When apply observer pattern an error occured I have the following code: class ISubscriber; class News { public: float getVersion() { return this->version; } void setVersion(float state) { this->version= state; this->notifyAllSubscribers(); } void attach(ISubscriber *observer) { this->subscribers.push_back(observer); } void notifyAllSubscribers() { for (vector<ISubscriber*>::iterator it = subscribers.begin(); it != subscribers.end(); it++){ (*(*it)).update(); } } private: vector<ISubscriber*> subscribers; float version; }; class ISubscriber { public: News *news; virtual void update() = 0; }; class Subscriber1 : public ISubscriber { public: Subscriber1(News *news) { this->news = news; this->news->attach(this); } void update() override { cout << "Subscriber1: A new version of the newspaper has been launched (v" << this->news->getVersion() << ")...