ceph/src/boost/libs/geometry/doc/src/examples/geometries/adapted/boost_fusion.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_fusion
  11 //` Shows how to combine Boost.Fusion with Boost.Geometry
  12
  13 #include <iostream>
  14
  15 #include <boost/fusion/include/adapt_struct_named.hpp>
  16
  17 #include <boost/geometry.hpp>
  18 #include <boost/geometry/geometries/adapted/boost_fusion.hpp>
  19
  20
  21 struct sample_point
  22 {
  23     double x, y, z;
  24 };
  25
  26 BOOST_FUSION_ADAPT_STRUCT(sample_point, (double, x) (double, y) (double, z))
  27 BOOST_GEOMETRY_REGISTER_BOOST_FUSION_CS(cs::cartesian)
  28
  29 int main()
  30 {
  31     sample_point a, b, c;
  32
  33     // Set coordinates the Boost.Geometry way (one of the ways)
  34     boost::geometry::assign_values(a, 3, 2, 1);
  35
  36     // Set coordinates the Boost.Fusion way
  37     boost::fusion::at_c<0>(b) = 6;
  38     boost::fusion::at_c<1>(b) = 5;
  39     boost::fusion::at_c<2>(b) = 4;
  40
  41     // Set coordinates the native way
  42     c.x = 9;
  43     c.y = 8;
  44     c.z = 7;
  45
  46     std::cout << "Distance a-b: " << boost::geometry::distance(a, b) << std::endl;
  47     std::cout << "Distance a-c: " << boost::geometry::distance(a, c) << std::endl;
  48
  49     return 0;
  50 }
  51
  52 //]
  53
  54 //[boost_fusion_output
  55 /*`
  56 Output:
  57 [pre
  58 Distance a-b: 5.19615
  59 Distance a-c: 10.3923
  60 ]
  61 */
  62 //]