#include <iostream>
#include <cstdlib>
using namespace std;

class IntPair
{
public:
    IntPair(int firstValue, int secondValue);
    IntPair operator++( );      //Prefix version
    IntPair operator++(int);    //Postfix version
    IntPair& operator+= (const IntPair& x);	// overload of += operator

    void setFirst(int newValue);
    void setSecond(int newValue);
    int getFirst( ) const;
    int getSecond( ) const;
private:
    int first;
    int second;
};

int main( )
{
    IntPair a(1,2);
    cout << "Postfix a++: Start value of object a: ";
    cout << a.getFirst( ) << " " << a.getSecond( ) << endl;
    IntPair b = a++; 
    cout << "Value returned: ";
    cout << b.getFirst( ) << " " << b.getSecond( ) << endl;
    cout << "Changed object: ";
    cout << a.getFirst( ) << " " << a.getSecond( ) << endl;

    a = IntPair(1, 2);
    cout << "Prefix ++a: Start value of object a: ";
    cout << a.getFirst( ) << " " << a.getSecond( ) << endl;
    IntPair c = ++a;   
    cout << "Value returned: ";
    cout << c.getFirst( ) << " " << c.getSecond( ) << endl;
    cout << "Changed object: ";
    cout << a.getFirst( ) << " " << a.getSecond( ) << endl;

    IntPair x(10,20);
    IntPair y(3, 5);
    cout << "Start value of object x: ";
    cout << x.getFirst( ) << " " << x.getSecond( ) << endl;
    cout << "Start value of object y: ";
    cout << y.getFirst( ) << " " << y.getSecond( ) << endl;
    
    x += y;		// add y to x

    cout << "After operation x += y...\n";
    cout << "New value of object x: ";
    cout << x.getFirst( ) << " " << x.getSecond( ) << endl;
    cout << "New value of object y: ";
    cout << y.getFirst( ) << " " << y.getSecond( ) << endl;

    return 0;
}

IntPair::IntPair(int firstValue, int secondValue) 
                     : first(firstValue), second(secondValue)
{/*Body intentionally empty*/}

IntPair IntPair::operator++(int ignoreMe) //postfix version
{
    int temp1 = first;
    int temp2 = second;
    first++;
    second++;
    return IntPair(temp1, temp2);
}

IntPair IntPair::operator++( ) //prefix version
{
    first++;
    second++;
    return IntPair(first, second);
}

IntPair& IntPair::operator+=(const IntPair& x)
{
   first += x.first;
   second += x.second;
   return *this;
}

void IntPair::setFirst(int newValue)
{
    first = newValue;
}

void IntPair::setSecond(int newValue)
{
    second = newValue;
}

int IntPair::getFirst( ) const
{
    return first;
}

int IntPair::getSecond( ) const
{
    return second;
}