ceph/src/boost/boost/geometry/views/segment_view.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   8 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 #ifndef BOOST_GEOMETRY_VIEWS_SEGMENT_VIEW_HPP
  15 #define BOOST_GEOMETRY_VIEWS_SEGMENT_VIEW_HPP
  16
  17
  18 #include <boost/range.hpp>
  19
  20 #include <boost/geometry/core/point_type.hpp>
  21 #include <boost/geometry/views/detail/points_view.hpp>
  22 #include <boost/geometry/algorithms/assign.hpp>
  23
  24
  25 namespace boost { namespace geometry
  26 {
  27
  28
  29 /*!
  30 \brief Makes a segment behave like a linestring or a range
  31 \details Adapts a segment to the Boost.Range concept, enabling the user to
  32     iterate the two segment points. The segment_view is registered as a LineString Concept
  33 \tparam Segment \tparam_geometry{Segment}
  34 \ingroup views
  35
  36 \qbk{before.synopsis,
  37 [heading Model of]
  38 [link geometry.reference.concepts.concept_linestring LineString Concept]
  39 }
  40
  41 \qbk{[include reference/views/segment_view.qbk]}
  42
  43 */
  44 template <typename Segment>
  45 struct segment_view
  46     : public detail::points_view
  47         <
  48             typename geometry::point_type<Segment>::type,
  49             2
  50         >
  51 {
  52     typedef typename geometry::point_type<Segment>::type point_type;
  53
  54     /// Constructor accepting the segment to adapt
  55     explicit segment_view(Segment const& segment)
  56         : detail::points_view<point_type, 2>(copy_policy(segment))
  57     {}
  58
  59 private :
  60
  61     class copy_policy
  62     {
  63     public :
  64         inline copy_policy(Segment const& segment)
  65             : m_segment(segment)
  66         {}
  67
  68         inline void apply(point_type* points) const
  69         {
  70             geometry::detail::assign_point_from_index<0>(m_segment, points[0]);
  71             geometry::detail::assign_point_from_index<1>(m_segment, points[1]);
  72         }
  73     private :
  74         Segment const& m_segment;
  75     };
  76
  77 };
  78
  79
  80 #ifndef DOXYGEN_NO_TRAITS_SPECIALIZATIONS
  81
  82 // All segment ranges can be handled as linestrings
  83 namespace traits
  84 {
  85
  86 template<typename Segment>
  87 struct tag<segment_view<Segment> >
  88 {
  89     typedef linestring_tag type;
  90 };
  91
  92 }
  93
  94 #endif // DOXYGEN_NO_TRAITS_SPECIALIZATIONS
  95
  96
  97 }} // namespace boost::geometry
  98
  99
 100 #endif // BOOST_GEOMETRY_VIEWS_SEGMENT_VIEW_HPP