ceph/src/boost/boost/geometry/algorithms/area_result.hpp

   1 // Boost.Geometry
   2
   3 // Copyright (c) 2017 Adam Wulkiewicz, Lodz, Poland.
   4
   5 // This file was modified by Oracle on 2020-2021.
   6 // Modifications copyright (c) 2020-2021 Oracle and/or its affiliates.
   7 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   8
   9 // Use, modification and distribution is subject to the Boost Software License,
  10 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  11 // http://www.boost.org/LICENSE_1_0.txt)
  12
  13 #ifndef BOOST_GEOMETRY_ALGORITHMS_AREA_RESULT_HPP
  14 #define BOOST_GEOMETRY_ALGORITHMS_AREA_RESULT_HPP
  15
  16
  17 #include <type_traits>
  18
  19 #include <boost/geometry/algorithms/detail/select_geometry_type.hpp>
  20
  21 #include <boost/geometry/core/coordinate_type.hpp>
  22 #include <boost/geometry/core/cs.hpp>
  23 #include <boost/geometry/core/geometry_types.hpp>
  24 #include <boost/geometry/core/tag.hpp>
  25 #include <boost/geometry/core/tags.hpp>
  26
  27 #include <boost/geometry/strategies/area/services.hpp>
  28 #include <boost/geometry/strategies/default_strategy.hpp>
  29 #include <boost/geometry/strategies/detail.hpp>
  30
  31 #include <boost/geometry/util/select_most_precise.hpp>
  32 #include <boost/geometry/util/sequence.hpp>
  33 #include <boost/geometry/util/type_traits.hpp>
  34
  35 namespace boost { namespace geometry
  36 {
  37
  38
  39 #ifndef DOXYGEN_NO_DETAIL
  40 namespace detail { namespace area
  41 {
  42
  43
  44 template
  45 <
  46     typename Geometry,
  47     typename Strategy,
  48     bool IsUmbrella = strategies::detail::is_umbrella_strategy<Strategy>::value
  49 >
  50 struct area_result
  51 {
  52     typedef decltype(std::declval<Strategy>().area(std::declval<Geometry>())) strategy_type;
  53     typedef typename strategy_type::template result_type<Geometry>::type type;
  54 };
  55
  56 template <typename Geometry, typename Strategy>
  57 struct area_result<Geometry, Strategy, false>
  58 {
  59     typedef typename Strategy::template result_type<Geometry>::type type;
  60 };
  61
  62
  63 template <typename Geometry>
  64 struct default_area_result
  65     : area_result
  66         <
  67             Geometry,
  68             typename geometry::strategies::area::services::default_strategy
  69                 <
  70                     Geometry
  71                 >::type
  72         >
  73 {};
  74
  75
  76 template <typename Curr, typename Next>
  77 struct more_precise_coordinate_type
  78     : std::is_same
  79         <
  80             typename geometry::coordinate_type<Curr>::type,
  81             typename geometry::select_most_precise
  82                 <
  83                     typename geometry::coordinate_type<Curr>::type,
  84                     typename geometry::coordinate_type<Next>::type
  85                 >::type
  86         >
  87 {};
  88
  89
  90 template <typename Curr, typename Next>
  91 struct more_precise_default_area_result
  92     : std::is_same
  93         <
  94             typename default_area_result<Curr>::type,
  95             typename geometry::select_most_precise
  96                 <
  97                     typename default_area_result<Curr>::type,
  98                     typename default_area_result<Next>::type
  99                 >::type
 100         >
 101 {};
 102
 103
 104 }} // namespace detail::area
 105 #endif //DOXYGEN_NO_DETAIL
 106
 107
 108 /*!
 109 \brief Meta-function defining return type of area function
 110 \ingroup area
 111 \note The return-type is defined by Geometry and Strategy
 112  */
 113 template
 114 <
 115     typename Geometry,
 116     typename Strategy = default_strategy
 117 >
 118 struct area_result
 119     : detail::area::area_result
 120         <
 121             typename detail::select_geometry_type
 122                 <
 123                     Geometry,
 124                     detail::area::more_precise_coordinate_type
 125                 >::type,
 126             Strategy
 127         >
 128 {};
 129
 130 template <typename Geometry>
 131 struct area_result<Geometry, default_strategy>
 132     : detail::area::default_area_result
 133         <
 134             typename detail::select_geometry_type
 135                 <
 136                     Geometry,
 137                     detail::area::more_precise_default_area_result
 138                 >::type
 139         >
 140 {};
 141
 142
 143 }} // namespace boost::geometry
 144
 145
 146 #endif // BOOST_GEOMETRY_ALGORITHMS_AREA_RESULT_HPP