Cpp code on complex operation like adding real and imaginary values?

#include <iostream>
class Complex {
  int m_real;
  int m_imag;

public:
  Complex() {}

  Complex(int real, int imag) : m_real(real), m_imag(imag) {}

  void display() {
    // print m_real, m_imag in a+ib format
  }

  Complex add(const Complex &r2) {  // c1.add(c2)
    int treal = m_real + r2.m_real; // this->m_real + ref.m_real
    int timag = m_imag + r2.m_imag;
    //Complex temp(treal, timag);
    //return temp;
    return Complex(treal,timag);
  }

  Complex multiply(const Complex &r2) {
    // TODO
  }

  Complex subtract(const Complex &r2) {
    // TODO
  }

  bool equals(const Complex &r2) { // c1.equals(c2)
    return m_real == r2.m_real && m_imag == r2.m_imag;
  }
};

int main() {
  Complex c1(2, 3);
  Complex c2(4, 5);
  Complex c3, c4, c5;

  c3 = c1.add(c2); // add(c1,c2)
  c5 = c1.multiply(c2);

  if (c1.equals(c2)) // if(equals(c1,c2))
    std::cout << "yes";
  else
    std::cout << "no";

  return 0;
}