ceph/src/boost/libs/geometry/doc/src/examples/geometries/adapted/boost_range/strided.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 //[boost_range_strided
  11 //` Shows how to use a Boost.Geometry ring, strided by Boost.Range adaptor
  12
  13 #include <iostream>
  14
  15 #include <boost/assign.hpp>
  16
  17 #include <boost/geometry.hpp>
  18 #include <boost/geometry/geometries/point_xy.hpp>
  19 #include <boost/geometry/geometries/ring.hpp>
  20 #include <boost/geometry/geometries/adapted/boost_range/strided.hpp>
  21
  22
  23 int main()
  24 {
  25     using namespace boost::assign;
  26     using boost::adaptors::strided;
  27
  28     typedef boost::geometry::model::d2::point_xy<int> xy;
  29     boost::geometry::model::ring<xy> ring;
  30     ring += xy(0, 0);
  31     ring += xy(0, 1);
  32     ring += xy(0, 2);
  33     ring += xy(1, 2);
  34     ring += xy(2, 2);
  35     ring += xy(2, 0);
  36
  37     boost::geometry::correct(ring);
  38
  39     std::cout
  40         << "Normal : " << boost::geometry::dsv(ring) << std::endl
  41         << "Strided: " << boost::geometry::dsv(ring | strided(2)) << std::endl;
  42
  43     return 0;
  44 }
  45
  46 //]
  47
  48 //[boost_range_strided_output
  49 /*`
  50 Output:
  51 [pre
  52 Normal : ((0, 0), (0, 1), (0, 2), (1, 2), (2, 2), (2, 0), (0, 0))
  53 Strided: ((0, 0), (0, 2), (2, 2), (0, 0))
  54 ]
  55 */
  56 //]