#include <boost/geometry.hpp>
#include <boost/geometry/geometries/register/point.hpp>

typedef std::pair<double, double> Point;
BOOST_GEOMETRY_REGISTER_POINT_2D(Point, double, boost::geometry::cs::cartesian, first, second);

//#define point1 first
//#define point2 second

struct Segment {
    Point point1;
    Point point2;
};

namespace boost { namespace geometry { namespace traits {
    template<> struct tag<Segment>
    {
        typedef segment_tag type;
    };

    template<> struct point_type<Segment>
    {
        typedef Point type;
    };

    template<> struct indexed_access<Segment, 0, 0> { static inline double get(Segment const& segment) { return segment.point1.first; } };
    template<> struct indexed_access<Segment, 0, 1> { static inline double get(Segment const& segment) { return segment.point1.second; } };
    template<> struct indexed_access<Segment, 1, 0> { static inline double get(Segment const& segment) { return segment.point2.first; } };
    template<> struct indexed_access<Segment, 1, 1> { static inline double get(Segment const& segment) { return segment.point2.second; } };
}}}

int main()
{
    Segment s1 = { Point(0, 0), Point(2, 2) };
    Segment s2 = { Point(0, 2), Point(2, 0) };
    std::cout << "len: " << boost::geometry::length(s1) << std::endl;
    std::vector<Point> out;
    boost::geometry::intersection(s1, s2, out);
    std::cout << "intersection: " << out[0].first << ", " << out[0].second << std::endl;
}