ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/detail/single_geometry.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4
   5 // This file was modified by Oracle on 2013, 2014.
   6 // Modifications copyright (c) 2013-2014, Oracle and/or its affiliates.
   7
   8 // Use, modification and distribution is subject to the Boost Software License,
   9 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  10 // http://www.boost.org/LICENSE_1_0.txt)
  11
  12 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  13
  14 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_SINGLE_GEOMETRY_HPP
  15 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_SINGLE_GEOMETRY_HPP
  16
  17 #include <boost/mpl/if.hpp>
  18 #include <boost/type_traits/is_base_of.hpp>
  19
  20 #include <boost/geometry/core/assert.hpp>
  21 #include <boost/geometry/core/tag.hpp>
  22 #include <boost/geometry/util/range.hpp>
  23
  24 namespace boost { namespace geometry {
  25
  26 #ifndef DOXYGEN_NO_DISPATCH
  27 namespace detail_dispatch {
  28
  29 // Returns single geometry by Id
  30 // for single geometries returns the geometry itself
  31 template <typename Geometry,
  32           bool IsMulti = boost::is_base_of
  33                             <
  34                                 multi_tag,
  35                                 typename geometry::tag<Geometry>::type
  36                             >::value
  37 >
  38 struct single_geometry
  39 {
  40     typedef Geometry & return_type;
  41
  42     template <typename Id>
  43     static inline return_type apply(Geometry & g, Id const& ) { return g; }
  44 };
  45
  46 // for multi geometries returns one of the stored single geometries
  47 template <typename Geometry>
  48 struct single_geometry<Geometry, true>
  49 {
  50     typedef typename boost::range_reference<Geometry>::type return_type;
  51
  52     template <typename Id>
  53     static inline return_type apply(Geometry & g, Id const& id)
  54     {
  55         BOOST_GEOMETRY_ASSERT(id.multi_index >= 0);
  56         typedef typename boost::range_size<Geometry>::type size_type;
  57         return range::at(g, static_cast<size_type>(id.multi_index));
  58     }
  59 };
  60
  61 } // namespace detail_dispatch
  62 #endif // DOXYGEN_NO_DISPATCH
  63
  64 #ifndef DOXYGEN_NO_DETAIL
  65 namespace detail {
  66
  67 template <typename Geometry>
  68 struct single_geometry_return_type
  69 {
  70     typedef typename detail_dispatch::single_geometry<Geometry>::return_type type;
  71 };
  72
  73 template <typename Geometry, typename Id>
  74 inline
  75 typename single_geometry_return_type<Geometry>::type
  76 single_geometry(Geometry & geometry, Id const& id)
  77 {
  78     return detail_dispatch::single_geometry<Geometry>::apply(geometry, id);
  79 }
  80
  81 template <typename Geometry, typename Id>
  82 inline
  83 typename single_geometry_return_type<Geometry const>::type
  84 single_geometry(Geometry const& geometry, Id const& id)
  85 {
  86     return detail_dispatch::single_geometry<Geometry const>::apply(geometry, id);
  87 }
  88
  89 } // namespace detail
  90 #endif // DOXYGEN_NO_DETAIL
  91
  92 }} // namespace boost::geometry
  93
  94 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_SINGLE_GEOMETRY_HPP