Programowanie Obiektowe w4

gistfile1.cpp

#include <iostream>
using namespace std;

class B
{
    int k;
public:
    friend class A;
    B():k(10){}
    int getK(){ return k; }
};

class A
{
    int i;
    B *b;
public:
    A():i(20), b(new B[10]){}
    A(int x):i(x), b(new B[10]){}
    ~A(){ delete [] b; }
    
    friend ostream & operator <<(ostream &oS, A &a);
    friend istream & operator >>(istream &iS, A &a);
    friend bool operator ==(A &a1, A &a2);
    
    A & operator =(A &a);
    B * operator ->();
    void operator ()();
    B & operator [](unsigned int size);
    bool operator !=(A &a1);
};

bool A::operator !=(A &a1)
{
    if(&a1 != this)
        return true;
    else
        return false;
}

bool operator==(A &a1, A &a2)
{
    if(&a1 == &a2)
        return true;
    else
        return false;
}

B & A::operator [](unsigned int size)
{
        return b[size];
}

void A::operator ()()
{
    cout << "Wartosc a.i = " << i << endl;
}

B * A::operator ->()
{
    if(b == NULL)
        cout << "Blad wskaznik zerowy!\n";    
    return b;
}

A & A::operator =(A& a)
{
    if(this != &a) {
        delete b;
        b = new B;
        b->k = a.b->k;
        i = a.i;
    }
    return *this;
}

ostream & operator <<(ostream &oS, A &a)
{
    oS << a.i << endl;
    return oS;
}

istream & operator >>(istream &iS, A &a)
{
    iS >> a.i;
    return iS;
}

int main() 
{
    A a, b, c(90);
        
    cout << b[2].getK() << endl;
    
    cout << b->getK() << endl;
    
    a();
    
    a = b = c;
    
    cin >> a;    
    cout << a;
    
    if(a == c)
        cout << "Prawda sa rowne a = c\n";
    else 
        cout<< "Falsz a != c\n";
    
    if(a != c)
        cout << "Prawda sa nierowne a != c\n";
    else 
        cout<< "Falsz sa rowne a = c\n";
}