#include <iostream>
using namespace std;

template <class T1, template <class T2> class Comparator> 
struct Pair
{
  Pair (const T1& p1_, const T1& p2_)
  :p1(p1_), p2(p2_)
  {
  }
  const T1& select() const
  {
    return Comparator<T1>::compare(p1, p2);
  }
  T1 p1, p2;
};

template <class T>
struct Smaller
{
  static const T& compare (const T& t1, const T& t2)
  {
    return t1 < t2 ? t1 : t2;
  }
};

template <class T>
struct Greater
{
  static const T& compare (const T& t1, const T& t2)
  {
    return t1 > t2 ? t1 : t2;
  }
};

int main()
{
    Pair<int, Smaller> p1(42,5);
    // p1 ist vom Typ T1, also int
    // Smaller wird mit p1, also int ausgeprägt
    // Pair wird mit int, Smaller ausgeprägt
    cout << p1.select() << endl;
    Pair<double, Greater> p2(16.0, 22.0);
    cout << p2.select() << endl;
}