ceph/src/boost/boost/geometry/core/tag.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 // This file was modified by Oracle on 2020.
   8 // Modifications copyright (c) 2020 Oracle and/or its affiliates.
   9 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  10
  11 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  12 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  13
  14 // Use, modification and distribution is subject to the Boost Software License,
  15 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  16 // http://www.boost.org/LICENSE_1_0.txt)
  17
  18 #ifndef BOOST_GEOMETRY_CORE_TAG_HPP
  19 #define BOOST_GEOMETRY_CORE_TAG_HPP
  20
  21
  22 #include <boost/geometry/core/tags.hpp>
  23 #include <boost/geometry/util/type_traits_std.hpp>
  24
  25
  26 namespace boost { namespace geometry
  27 {
  28
  29 namespace traits
  30 {
  31
  32 /*!
  33 \brief Traits class to attach a tag to a geometry
  34 \details All geometries should implement a traits::tag<G>::type metafunction to indicate their
  35     own geometry type.
  36 \ingroup traits
  37 \par Geometries:
  38     - all geometries
  39 \par Specializations should provide:
  40     - typedef XXX_tag type; (point_tag, box_tag, ...)
  41 \tparam Geometry geometry
  42 */
  43 template <typename Geometry, typename Enable = void>
  44 struct tag
  45 {
  46     typedef void type;
  47 };
  48
  49 } // namespace traits
  50
  51
  52
  53 /*!
  54 \brief \brief_meta{type, tag, \meta_geometry_type}
  55 \details With Boost.Geometry, tags are the driving force of the tag dispatching
  56     mechanism. The tag metafunction is therefore used in every free function.
  57 \tparam Geometry \tparam_geometry
  58 \ingroup core
  59
  60 \qbk{[include reference/core/tag.qbk]}
  61 */
  62 template <typename Geometry>
  63 struct tag
  64 {
  65     typedef typename traits::tag
  66         <
  67             typename util::remove_cptrref<Geometry>::type
  68         >::type type;
  69 };
  70
  71 }} // namespace boost::geometry
  72
  73 #endif // BOOST_GEOMETRY_CORE_TAG_HPP