ceph/src/boost/boost/geometry/strategies/concepts/centroid_concept.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_STRATEGIES_CONCEPTS_CENTROID_CONCEPT_HPP
  15 #define BOOST_GEOMETRY_STRATEGIES_CONCEPTS_CENTROID_CONCEPT_HPP
  16
  17
  18
  19 #include <boost/concept_check.hpp>
  20
  21
  22 namespace boost { namespace geometry { namespace concepts
  23 {
  24
  25
  26 /*!
  27     \brief Checks strategy for centroid
  28     \ingroup centroid
  29 */
  30 template <typename Strategy>
  31 class CentroidStrategy
  32 {
  33 #ifndef DOXYGEN_NO_CONCEPT_MEMBERS
  34
  35     // 1) must define state_type,
  36     typedef typename Strategy::state_type state_type;
  37
  38     // 2) must define point_type,
  39     typedef typename Strategy::point_type point_type;
  40
  41     // 3) must define point_type, of polygon (segments)
  42     typedef typename Strategy::segment_point_type spoint_type;
  43
  44     struct check_methods
  45     {
  46         static void apply()
  47         {
  48             Strategy *str = 0;
  49             state_type *st = 0;
  50
  51             // 4) must implement a static method apply,
  52             // getting two segment-points
  53             spoint_type const* sp = 0;
  54             str->apply(*sp, *sp, *st);
  55
  56             // 5) must implement a static method result
  57             //  getting the centroid
  58             point_type *c = 0;
  59             bool r = str->result(*st, *c);
  60
  61             boost::ignore_unused_variable_warning(str);
  62             boost::ignore_unused_variable_warning(r);
  63         }
  64     };
  65
  66 public :
  67     BOOST_CONCEPT_USAGE(CentroidStrategy)
  68     {
  69         check_methods::apply();
  70     }
  71 #endif
  72 };
  73
  74
  75 }}} // namespace boost::geometry::concepts
  76
  77
  78 #endif // BOOST_GEOMETRY_STRATEGIES_CONCEPTS_CENTROID_CONCEPT_HPP