// operator overloading syntax

#include <iostream.h>

class integer {
    int i;
public:
    integer(int I) {i = I;}

    const integer operator+(const integer& rv) const {
        cout << "operator+, ";
        return integer(i + rv.i);
    }

    integer& operator+=(const integer& rv)  {
        cout << "operator+=" << endl;
        i += rv.i;
        return *this;
    }
};

main( )  {
    cout << "built-in types (for 'ints'): +, +=" << endl;
    int i = 1, j = 2, k = 3;
    k += i + j;
    cout << endl;
    cout << "user-defined types (for 'integers'): ";
    integer I(1), J(2), K(3);
    K += I + J;

    getchar();
}