ceph/src/boost/libs/geometry/doc/src/examples/core/tag_cast.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // QuickBook Example
   3
   4 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5
   6 // Use, modification and distribution is subject to the Boost Software License,
   7 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9
  10 //[tag_cast
  11 //` Check if the polygon_tag can be casted to the areal_tag
  12
  13 #include <iostream>
  14 #include <typeinfo>
  15
  16 #include <boost/geometry.hpp>
  17 #include <boost/geometry/geometries/polygon.hpp>
  18 #include <boost/geometry/geometries/point_xy.hpp>
  19
  20 namespace geo = boost::geometry;
  21 int main()
  22 {
  23     typedef geo::model::d2::point_xy<double> point_type;
  24     typedef geo::model::polygon<point_type> polygon_type;
  25
  26     typedef geo::tag<polygon_type>::type tag;
  27     typedef geo::tag_cast<tag, geo::linear_tag, geo::areal_tag>::type base_tag;
  28
  29     std::cout << "tag: " << typeid(tag).name() << std::endl
  30         << "base tag: " << typeid(base_tag).name() << std::endl;
  31
  32     return 0;
  33 }
  34
  35 //]
  36
  37
  38 //[tag_cast_output
  39 /*`
  40 Output (in MSVC):
  41 [pre
  42 tag: struct boost::geometry::polygon_tag
  43 base tag: struct boost::geometry::areal_tag
  44 ]
  45 */
  46 //]