Подключение библиотеки - C++ - Ответ 506151

//lib.h
#pragma once
#include <iostream>
#include <conio.h>
#include <vector>
#include "Firm.h"
#include "Point.h"
#include "Penta.h"
#include "Lack.h"
#include "Akryl.h"
.....

#include "Lib.h"
int main()
{
    Firm* f = Firm::getInstance();
    Point* p1 = new Penta(f);
    Point* p2 = new Lack(f);
    Point* p3 = new Akryl(f);
...

#include "Lib.h"
Akryl::Akryl(Firm* f)
{
    f->Subscribe(this);
}

#pragma once
class Point;
class Firm
{
    std::vector<Point*> point;
    static Firm* instance;
    Firm(){};
public:
    static Firm* getInstance()
    {
        if(!instance)
        {
            instance = new Firm;
        }
        else
        {
            return instance;
        }
    }
    void Subscribe(Point*);
    void Unsubscribe(int);
    void Notyfy(int);
    void Reset();
};
Firm *Firm::instance = NULL;