text: // Boost.Geometry (aka GGL, Generic Geometry Library)
  
  // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
  // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
  // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
  // Copyright (c) 2013 Adam Wulkiewicz, Lodz, Poland.
  
  // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  
  // Use, modification and distribution is subject to 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)
  
  #ifndef BOOST_GEOMETRY_EXTENSIONS_ALGEBRA_ALGORITHMS_ASSIGN_HPP
  #define BOOST_GEOMETRY_EXTENSIONS_ALGEBRA_ALGORITHMS_ASSIGN_HPP
  
  #include <boost/geometry/algorithms/assign.hpp>
  
  #include <boost/geometry/extensions/algebra/core/tags.hpp>
  
  #include <boost/geometry/extensions/algebra/algorithms/detail.hpp>
  
  namespace boost { namespace geometry
  {
  
  #ifndef DOXYGEN_NO_DISPATCH
  namespace dispatch {
  
  template <typename Vector>
  struct assign_zero<vector_tag, Vector>
  {
      static inline void apply(Vector & g)
      {
          detail::algebra::assign_value<
              Vector,
              typename coordinate_type<Vector>::type,
              0, dimension<Vector>::type::value
          >::apply(g, 0);
      }
  };
  
  template <typename GeometryTag, typename Geometry>
  struct assign_identity
  {
      BOOST_MPL_ASSERT_MSG(false, NOT_IMPLEMENTED_FOR_THIS_GEOMETRY, (GeometryTag, Geometry));
  };
  
  template <typename R>
  struct assign_identity<rotation_quaternion_tag, R>
  {
      static inline void apply(R & g)
      {
          set<0>(g, 1); set<1>(g, 0); set<2>(g, 0); set<3>(g, 0);
      }
  };
  
  template <typename R>
  struct assign_identity<rotation_matrix_tag, R>
  {
      static inline void apply(R & r)
      {
          detail::algebra::identity_matrix<
              R, 0, 0, dimension<R>::value, dimension<R>::value
          >::apply(r);
      }
  };
  
  } // namespace dispatch
  #endif // DOXYGEN_NO_DISPATCH
  
  // TODO
  // Use assign_zero for initialization of 0-angle rotation instead of assign_identity?
  
  /*!
  \brief assign identity to Transformation
  \ingroup assign
  \details The assign_identity function initializes a rotation or transformation with values indicating no rotation
  \tparam Rotation The rotation type.
  \param rotation The rotation.
   */
  template <typename Rotation>
  inline void assign_identity(Rotation & rotation)
  {
      concept::check<Rotation>();
  
      dispatch::assign_identity<
          typename tag<Rotation>::type,
          Rotation
      >::apply(rotation);
  }
  
  #ifndef DOXYGEN_NO_DISPATCH
  namespace dispatch {
  
  template <typename V>
  struct assign<vector_tag, V, 2>
  {
      typedef typename coordinate_type<V>::type coordinate_type;
  
      template <typename T>
      static inline void apply(V& v, T const& c1, T const& c2)
      {
          set<0>(v, boost::numeric_cast<coordinate_type>(c1));
          set<1>(v, boost::numeric_cast<coordinate_type>(c2));
      }
  };
  
  template <typename V>
  struct assign<vector_tag, V, 3>
  {
      typedef typename coordinate_type<V>::type coordinate_type;
  
      template <typename T>
      static inline void apply(V& v, T const& c1, T const& c2, T const& c3)
      {
          set<0>(v, boost::numeric_cast<coordinate_type>(c1));
          set<1>(v, boost::numeric_cast<coordinate_type>(c2));
          set<2>(v, boost::numeric_cast<coordinate_type>(c3));
      }
  };
  
  } // namespace dispatch
  #endif // DOXYGEN_NO_DISPATCH
  
  
  }} // namespace boost::geometry
  
  #endif // BOOST_GEOMETRY_EXTENSIONS_ALGEBRA_ALGORITHMS_ASSIGN_HPP
  