// ####################### templates.cpp

#include <iostream>
#include <vector>
#include <set>

template < class T > T twice (T a)
{
  return 2 * a;
}

template < class iter > void
view (iter b, iter e)
{
  iter it;
  for (it = b; it != e; it++) {
    cout << *it << "\n";
  }
  cout << "\n";
}

#define BE(v) v.begin(), v.end()

main ()
{
  cout << twice (2) << "\n";
  double a = 3.0;
  cout << twice (a) << "\n";

  cout << "\n";

  set < int >s;
  s.insert (7);
  s.insert (6);
  view (s.begin (), s.end ());

  vector < int >v (3, 2);
  view (BE (v));
}