// Listing 5.4 - demonstrates passing by value

 #include <iostream>

 

 void swap(int x, int y);

 

 int main()

 {

     int x = 5, y = 10;

     std::cout << "Main. Before swap, x: " << x 

                                 << " y: " << y << "\n";

     swap(x,y);

     std::cout << "Main. After swap, x: " << x 

                                << " y: " << y << "\n";

     return 0;

 }

 

 void swap (int x, int y)

 {

     int temp;

     std::cout << "Swap. Before swap, x: " << x 

                                 << " y: " << y << "\n";

     temp = x;

     x = y;

     y = temp;

     std::cout << "Swap. After swap, x: " << x 

                                << " y: " << y << "\n";

 }