shallow/deep copy

cars-operators.cpp

#include <iostream>
#include <string>

using namespace std;

class Pojazd {
private:
    string lusterko[3] = {"lewe", "prawe"};
protected:
    int id = 0;
public:
    void setId(int id);

public:
    int getId() const;

public:
    friend class Samochod;
    Pojazd& operator=(const Pojazd&);
};

Pojazd &Pojazd::operator=(const Pojazd& pojazd) {
    return *this;
}

class Samochod : Pojazd {
public:
    Samochod& operator=(const Samochod&);
};

int Pojazd::getId() const {
    return id;
}

void Pojazd::setId(int id) {
    Pojazd::id = id;
}

Samochod &Samochod::operator=(const Samochod &wzor) {
    if (this != &wzor)
    {
        (Pojazd&)*this = wzor;
        this->lusterko[2] = "wsteczne";
    }
    return *this;
}

int main() {
    Pojazd p1;
    p1.setId(2);
    Pojazd p2 = p1, p3;
    p3.setId(4);
    p3 = p1;
    cout << "p1: " << p1.getId() << endl;
    cout << "p2: " << p2.getId() << endl;
    cout << "p3: " << p3.getId() << endl;
    return 0;
}

out:
p1: 2
p2: 2
p3: 4