Cyclic.h

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/* ----------------------------------------------------------------------------

 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)

 * See LICENSE for the license information

 * -------------------------------------------------------------------------- */

#include <gtsam/base/Group.h>
#include <gtsam/base/Testable.h>
#include <iostream> // for cout :-(

namespace gtsam {

template<size_t N>
class Cyclic {
  size_t i_; 
public:
  Cyclic(size_t i) :
      i_(i) {
    assert(i < N);
  }
  Cyclic():i_(0) {
  }
  static Cyclic identity() { return Cyclic();}

  operator size_t() const {
    return i_;
  }
  Cyclic operator+(const Cyclic& h) const {
    return (i_ + h.i_) % N;
  }
  Cyclic operator-(const Cyclic& h) const {
    return (N + i_ - h.i_) % N;
  }
  Cyclic operator-() const {
    return (N - i_) % N;
  }
  void print(const std::string& s = "") const {
    std::cout << s << i_ << std::endl;
  }
  bool equals(const Cyclic& other, double tol = 1e-9) const {
    return other.i_ == i_;
  }
};

template<size_t N>
struct traits<Cyclic<N> > : internal::AdditiveGroupTraits<Cyclic<N> >, //
    Testable<Cyclic<N> > {
};

} // \namespace gtsam