Boost.Polygon's polygon_with_holes_data

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##### Boost.Polygon's polygon_with_holes_data

Boost.Polygon's polygon type supporting holes (boost::polygon::polygon_with_holes_data) is adapted to the Boost.Geometry Polygon Concept.

###### Description

Boost.Polygon's points (as well as polygons) can be used by Boost.Geometry. The two libraries can therefore be used together. Using a boost::polygon::polygon_with_holes_data<...>, algorithms from both Boost.Polygon and Boost.Geometry can be called.

###### Model of

Polygon Concept

###### Header

`#include <boost/geometry/geometries/adapted/boost_polygon.hpp>`

The standard header `boost/geometry.hpp` does not include this header.

###### Example

Shows how to use Boost.Polygon polygon_with_holes_data within Boost.Geometry

    #include <iostream>
    #include <boost/geometry.hpp>
    #include <boost/geometry/geometries/adapted/boost_polygon.hpp>

    int main()
    {
        typedef boost::polygon::polygon_with_holes_data<int> polygon;
        typedef boost::polygon::polygon_traits<polygon>::point_type point;
        typedef boost::polygon::polygon_with_holes_traits<polygon>::hole_type hole;

        point pts[5] = {
            boost::polygon::construct<point>(0, 0),
            boost::polygon::construct<point>(0, 10),
            boost::polygon::construct<point>(10, 10),
            boost::polygon::construct<point>(10, 0),
            boost::polygon::construct<point>(0, 0)
        };
        point hole_pts[5] = {
            boost::polygon::construct<point>(1, 1),
            boost::polygon::construct<point>(9, 1),
            boost::polygon::construct<point>(9, 9),
            boost::polygon::construct<point>(1, 9),
            boost::polygon::construct<point>(1, 1)
        };

        hole hls[1];
        boost::polygon::set_points(hls[0], hole_pts, hole_pts+5);

        polygon poly;
        boost::polygon::set_points(poly, pts, pts+5);
        boost::polygon::set_holes(poly, hls, hls+1);

        std::cout << "Area (using Boost.Geometry): "
            << boost::geometry::area(poly) << std::endl;
        std::cout << "Area (using Boost.Polygon): "
            << boost::polygon::area(poly) << std::endl;

        return 0;
    }

Output:

    Area (using Boost.Geometry): 36
    Area (using Boost.Polygon): 36