libs/geometry/doc/src/examples/core/ring_type.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 //[ring_type
  11 //`Shows how to use the ring_type metafunction, as well as interior_type
  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 int main()
  21 {
  22     typedef boost::geometry::model::d2::point_xy<double> point;
  23     typedef boost::geometry::model::polygon<point> polygon;
  24
  25     typedef boost::geometry::ring_type<polygon>::type ring_type;
  26     typedef boost::geometry::interior_type<polygon>::type int_type;
  27
  28     std::cout << typeid(ring_type).name() << std::endl;
  29     std::cout << typeid(int_type).name() << std::endl;
  30
  31     // So int_type defines a collection of rings,
  32     // which is a Boost.Range compatible range
  33     // The type of an element of the collection is the very same ring type again.
  34     // We show that.
  35     typedef boost::range_value<int_type>::type int_ring_type;
  36
  37     std::cout
  38         << std::boolalpha
  39         << boost::is_same<ring_type, int_ring_type>::value
  40         << std::endl;
  41
  42     return 0;
  43 }
  44
  45 //]
  46
  47 //[ring_type_output
  48 /*`
  49 Output (using gcc):
  50 [pre
  51           N5boost8geometry5model4ringINS1_2d28point_xyIdNS0_2cs9cartesianEEELb1ELb1ESt6vectorSaEE
  52 St6vectorIN5boost8geometry5model4ringINS2_2d28point_xyIdNS1_2cs9cartesianEEELb1ELb1ES_SaEESaIS9_EE
  53 true
  54 ]
  55 */
  56 //]