int DoF = Base::DoF;
  /** \brief number of internal parameters used */
  static const int num_parameters = Base::num_parameters;
  /** \brief group transformations are NxN matrices */
  static const int N = Base::N;
  /** \brief group transfomation type */
  typedef typename Base::Transformation Transformation;
  /** \brief point type */
  typedef typename Base::Point Point;
  /** \brief tangent vector type */
  typedef typename Base::Tangent Tangent;
  /** \brief adjoint transformation type */
  typedef typename Base::Adjoint Adjoint;

  EIGEN_INHERIT_ASSIGNMENT_EQUAL_OPERATOR(Map)
  using Base::operator*=;
  using Base::operator*;

  EIGEN_STRONG_INLINE
  Map(const Scalar* coeffs) : unit_complex_(coeffs) {
  }

  /**
   * \brief Accessor of unit complex number
   *
   * No direct write access is given to ensure the complex number stays
   * normalized.
   */
  EIGEN_STRONG_INLINE
  ConstComplexReference unit_complex() const {
    return unit_complex_;
  }

protected:
  const Map<const Matrix<Scalar,2,1>,_Options> unit_complex_;
};

}


#endif // SOPHUS_SO2_HPP



// Copyright Aleksey Gurtovoy 2000-2004
//
// Distributed under the Boost Software License, Version 1.0. 
// (See accompanying file LICENSE_1_0.txt or copy at 
// http://www.boost.org/LICENSE_1_0.txt)
//

// Preprocessed version of "boost/mpl/aux_/reverse_iter_fold_impl.hpp" header
// -- DO NOT modify by hand!

namespace boost { namespace mpl { namespace aux {

/// forward declaration

template<
      long N
    , typename First
    , typename Last
    , typename State
    , typename BackwardOp
    , typename ForwardOp
    >
struct reverse_iter_fold_impl;

template< long N >
struct reverse_iter_fold_chunk;

template<> struct reverse_iter_fold_chunk<0>
{
    template<
          typename First
        , typename Last
        , typename State
        , typename BackwardOp
        , typename ForwardOp
        >
    struct result_
    {
        typedef First iter0;
        typedef State fwd_state0;
        typedef fwd_state0 bkwd_state0;
        typedef bk