// test_swap_template.cpp   demonstrate pass parameter by reference         

template <class some_type>
void swap_any(some_type &v1, some_type &v2)
{
  some_type tmp = v2;
  v2 = v1;
  v1 = tmp;
} // end swap_any


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

int main()                            // C++ test swap
{
  int i=10;
  int j=20;
  cout << "before swap  i= " << i << "  j= " << j << endl;
  swap_any(i, j);
  cout << "after  swap  i= " << i << "  j= " << j << endl;
  
  string s10("string 10");
  string s20("string 20, longer OK");
  cout << "before swap  s10= " << s10 << "  s20= "  << s20 << endl;
  swap_any(s10, s20);
  cout << "after  swap  s10= " << s10 << "  s20= "  << s20 << endl;
  
  return 0;
} // end main