#ifndef Ring3_H
#define Ring3_H

#include "cycle_facade.H"
#include <vector>

template<typename T, template <typename A> class CONT=std::vector>
class Ring {
public:
  typedef typename boost::cycle_facade<typename CONT<T>::iterator> iterator;
  typedef typename boost::cycle_facade<typename CONT<T>::const_iterator> const_iterator;

  Ring() : _size(0) {}

  explicit Ring (size_t n) :
    _size (n), v (n+1), it (boost::make_cycle_facade (v.begin(), v.begin(), v.end())) {}

  iterator begin() { return it; }

  iterator end() { return it + _size; }

  const iterator begin() const { return it; }

  const iterator end() const { return it + _size; }

  void shift (int n) { it += n; }

  T& operator[] (int n) { return it[n]; }

  const T& operator[] (int n) const { return it[n]; }

  size_t size() const { return _size; }

  void resize (size_t n) {
    v.resize (n+1);
    _size = n;
    it = boost::make_cycle_facade (v.begin(), v.begin(), v.end());
  }

  size_t _size;
  CONT<T> v;
  iterator it;
};

#endif