32         typedef model::d2::point_xy<double> point;  in main()  typedef
33         typedef model::polygon<point> polygon;  in main()
34         typedef model::linestring<point> linestring;  in main()
41         ls1 += point(1,2);  in main()
42         ls1 += point(3,4), point(5,6), point(7,8);  in main()
47         push_back(ls2)(point(1, 2))(point(3, 4));  in main()
51         linestring ls3 = list_of(point(1,2))(point(3,4));  in main()
56         push_back(ls4)(point(0, 0)).range(ls2).range(ls3);  in main()
64             (point(0, 0))  in main()
65             (point(0, 2))  in main()
66             (point(2, 2))  in main()
67             (point(2, 0))  in main()
68             (point(0, 0))  in main()