#pragma once
#include <iostream>
#include <string>
#include <memory>
#include <vector>
#include "Observer.h"

using namespace std;

class Subject
{
public:
    virtual ~Subject(){}
    virtual void notify() = 0;
    virtual void attach(Observer* this_observer) = 0;
    virtual void dettach(Observer* this_observer) = 0;
};