ceph/src/boost/libs/geometry/include/boost/geometry/core/exterior_ring.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
  15 #ifndef BOOST_GEOMETRY_CORE_EXTERIOR_RING_HPP
  16 #define BOOST_GEOMETRY_CORE_EXTERIOR_RING_HPP
  17
  18
  19 #include <boost/mpl/assert.hpp>
  20 #include <boost/type_traits/is_const.hpp>
  21 #include <boost/type_traits/remove_const.hpp>
  22
  23
  24 #include <boost/geometry/core/ring_type.hpp>
  25 #include <boost/geometry/core/tag.hpp>
  26 #include <boost/geometry/core/tags.hpp>
  27 #include <boost/geometry/util/add_const_if_c.hpp>
  28
  29
  30 namespace boost { namespace geometry
  31 {
  32
  33 namespace traits
  34 {
  35
  36
  37 /*!
  38     \brief Traits class defining access to exterior_ring of a polygon
  39     \details Should define const and non const access
  40     \ingroup traits
  41     \tparam Polygon the polygon type
  42     \par Geometries:
  43         - polygon
  44     \par Specializations should provide:
  45         - static inline RING& get(POLY& )
  46         - static inline RING const& get(POLY const& )
  47 */
  48 template <typename Polygon>
  49 struct exterior_ring
  50 {
  51     BOOST_MPL_ASSERT_MSG
  52         (
  53             false, NOT_IMPLEMENTED_FOR_THIS_POLYGON_TYPE
  54             , (types<Polygon>)
  55         );
  56 };
  57
  58
  59 } // namespace traits
  60
  61
  62 #ifndef DOXYGEN_NO_DISPATCH
  63 namespace core_dispatch
  64 {
  65
  66
  67 template <typename Tag, typename Geometry>
  68 struct exterior_ring
  69 {
  70     BOOST_MPL_ASSERT_MSG
  71         (
  72             false, NOT_IMPLEMENTED_FOR_THIS_GEOMETRY_TYPE
  73             , (types<Geometry>)
  74         );
  75 };
  76
  77
  78 template <typename Polygon>
  79 struct exterior_ring<polygon_tag, Polygon>
  80 {
  81     static
  82     typename geometry::ring_return_type<Polygon>::type
  83         apply(typename add_const_if_c
  84             <
  85                 boost::is_const<Polygon>::type::value,
  86                 Polygon
  87             >::type& polygon)
  88     {
  89         return traits::exterior_ring
  90             <
  91                 typename boost::remove_const<Polygon>::type
  92             >::get(polygon);
  93     }
  94 };
  95
  96
  97 } // namespace core_dispatch
  98 #endif // DOXYGEN_NO_DISPATCH
  99
 100
 101 /*!
 102     \brief Function to get the exterior_ring ring of a polygon
 103     \ingroup exterior_ring
 104     \note OGC compliance: instead of ExteriorRing
 105     \tparam Polygon polygon type
 106     \param polygon the polygon to get the exterior ring from
 107     \return a reference to the exterior ring
 108 */
 109 template <typename Polygon>
 110 inline typename ring_return_type<Polygon>::type exterior_ring(Polygon& polygon)
 111 {
 112     return core_dispatch::exterior_ring
 113         <
 114             typename tag<Polygon>::type,
 115             Polygon
 116         >::apply(polygon);
 117 }
 118
 119
 120 /*!
 121 \brief Function to get the exterior ring of a polygon (const version)
 122 \ingroup exterior_ring
 123 \note OGC compliance: instead of ExteriorRing
 124 \tparam Polygon polygon type
 125 \param polygon the polygon to get the exterior ring from
 126 \return a const reference to the exterior ring
 127
 128 \qbk{distinguish,const version}
 129 */
 130 template <typename Polygon>
 131 inline typename ring_return_type<Polygon const>::type exterior_ring(
 132         Polygon const& polygon)
 133 {
 134     return core_dispatch::exterior_ring
 135         <
 136             typename tag<Polygon>::type,
 137             Polygon const
 138         >::apply(polygon);
 139 }
 140
 141
 142 }} // namespace boost::geometry
 143
 144
 145 #endif // BOOST_GEOMETRY_CORE_EXTERIOR_RING_HPP