// Compile with:
// g++ -Wall -o komplex-class komplex-class.cc

#include <iostream>

struct komplex {

  double re;
  double im;

  // Default (empty) constructor.

  komplex() {
    re = 0;
    im = 0;
  }

  // Constructor that creates a komplex out of a double.

  komplex(double r) {
    re = r;
    im = 0;
  }

  // Constructor that creates a komplex out of two doubles.

  komplex(double r, double i) {
    re = r;
    im = i;
  }

  // Implementation of "this += b".

  komplex & operator += (const komplex & b) {
    re += b.re;
    im += b.im;
    return *this;
  }

  // Implementation of "this -= b".

  komplex & operator -= (const komplex & b) {
    re -= b.re;
    im -= b.im;
    return *this;
  }

  // Prints a komplex to cout.

  void print() {
    std::cout << "komplex[" << re << "," << im << "]";
  }
};

// Implementation of "a+b".

komplex operator + (const komplex & a, const komplex & b) {
  return komplex(a.re+b.re, a.im+b.im);
}

// Implementation of "a-b".

komplex operator - (const komplex & a, const komplex & b) {
  return komplex(a.re-b.re, a.im-b.im);
}

int main() {

  komplex a;
  komplex b = 1;
  komplex c(2,4);
  komplex d = c;
  komplex e = b+c;

  std::cout << "a         = "; a.print(); std::cout << std::endl;
  std::cout << "b = 1     = "; b.print(); std::cout << std::endl;
  std::cout << "c = (2,4) = "; c.print(); std::cout << std::endl;
  std::cout << "d = c     = "; d.print(); std::cout << std::endl;
  std::cout << "e = b+c   = "; e.print(); std::cout << std::endl;

  b += e;
  std::cout << "b += e    = "; b.print(); std::cout << std::endl;

  return 0;
}