supraincarcare operatori

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <iostream>

using namespace std;
class Complex {
private:
    float re;
    float im;
public:
    Complex(float re = 0, float im = 0);
    void afisare();
    Complex& operator ++();
    Complex operator +(Complex z);
    Complex& operator ++(int);
    Complex operator ~();
    Complex operator +=(Complex z);
    Complex operator /(Complex z);
    friend Complex operator -(Complex z1,
        Complex z2);
    friend Complex operator -(Complex z);
};

Complex& Complex::operator ++() {
    //re += 1;
    ++re;
    printf("preincrementare\n");
    return *this;
}

Complex& Complex::operator ++(int n) {
    re++;
    printf("postincrementare\n");
    return *this;
}

Complex::Complex(float re, float im) {
    this->re = re;
    this->im = im;
}
void Complex::afisare() {
    printf("%-g%+g*i\n", re, im);
}
Complex Complex::operator +(Complex z) {
    Complex rez;
    rez.re = this->re + z.re;
    rez.im = this->im + z.im;
    return rez;
}
Complex Complex::operator /(Complex z) {
    Complex rez;
    rez.re = this->re + z.re;
    rez.im = this->im + z.im;
    return rez;
}
Complex Complex::operator +=(Complex z) {
//  Complex rez;
     re += z.re;
     this->im += z.im;

    return *this;
}

Complex Complex::operator ~() {
    return Complex(re, -im);
}
Complex operator -(Complex z1, Complex z2) {
    cout <<"hihi";
    return Complex(z1.re - z2.re, z1.im - z2.im);
}
Complex operator -(Complex z) {
    cout << "haha";
    return Complex(-z.re, -z.im);
}

void main() {
    Complex z1(4, 5), z2(3, 1), z;
    z = z1 + z2; z.afisare();
    z = z1 - z2; z.afisare();
    z = ~z1; z.afisare();
    z = -z1; z.afisare();
    z = z1;


    cout << endl << endl;
    z.afisare();
    z1 += z1;
    z1.afisare();
    z2.afisare();
    z = z1 / z2;
    z.afisare();
    ++z;
    z++;
    z.afisare();
    _getch();
}