Calculating Complex number using Friend Function in CPP

complex-number-friend.cpp

#include <iostream>
using namespace std;

class Complex{
    int real,img;
public:
    Complex(int real=0, int img=0){
        this->real = real;
        this->img = img;
    }
    friend Complex compute(Complex, Complex);
    friend void display(Complex);
};

Complex compute(Complex c1,Complex c2){
    Complex temp;
    temp.real = c1.real+c2.real;
    temp.img = c1.img+c2.img;
    return temp;
}

void display(Complex temp){
    cout << temp.real << "+i" << temp.img << endl;
}

int main(){
    Complex c1(1,2);
    Complex c2(3,4);
    Complex t = compute(c1,c2);
    display(t);
}