// A demonstration of passing by value.
 // demonstrates passing by value

  #include <iostream.h>

  void swap(int x, int y);

 int main()
 {
 int x = 5, y = 10;

 cout << "Main. Before swap, x: " << x << " y: " << y <<
"\n";
 swap(x,y);
 cout << "Main. After swap, x: " << x << " y: " << y <<
"\n";
 return 0;
 }

 void swap (int x, int y)
 {
 int temp;

 cout << "Swap. Before swap, x: " << x << " y: " << y <<
"\n";
 temp = x;
 x = y;
 y = temp;

 cout << "Swap. After swap, x: " << x << " y: " << y <<
";

 }