Point iterator providing equal access on Polyhedron_3 and Surfacemesh

PointIterator.cpp

#include <CGAL/Simple_cartesian.h>
typedef CGAL::Simple_cartesian<double> Kernel;
typedef Kernel::FT Scalar;
typedef Kernel::Point_3 Point;
typedef Kernel::Vector_3 Vector;

#include <CGAL/Surface_mesh.h>
typedef CGAL::Surface_mesh<Point> Surfacemesh;

#include <CGAL/Polyhedron_3.h>
typedef CGAL::Polyhedron_3<Kernel> Polyhedron;

#include <CGAL/centroid.h>
#include <CGAL/bounding_box.h>

#include <boost/ref.hpp>

class PointIteratorSurfacemesh
{
   private:
    struct V2P {
        typedef Point result_type;
        boost::reference_wrapper<const Surfacemesh> mesh_;    // CGAL::bounding_box() needs assignable iterators, not only a ref
        V2P( const Surfacemesh& mesh ) : mesh_( mesh ) {}
        const Point& operator()( Surfacemesh::Vertex_index v ) const { return mesh_.get().point( v ); }
    };

    V2P v2p_;
    const Surfacemesh& mesh_;
    typedef boost::transform_iterator<V2P, Surfacemesh::Vertex_iterator> Point_iterator;

   public:
    PointIteratorSurfacemesh( const Surfacemesh& mesh ) : v2p_( mesh ), mesh_( mesh ) {}
    Point_iterator begin() { return boost::make_transform_iterator( mesh_.vertices().begin(), v2p_ ); }
    Point_iterator end() { return boost::make_transform_iterator( mesh_.vertices().end(), v2p_ ); }
};
class PointIteratorPolyhedron
{
   private:
    const Polyhedron& mesh_;
    typedef Polyhedron::Point_const_iterator iterator;

   public:
    PointIteratorPolyhedron( const Polyhedron& mesh ) : mesh_( mesh ) {}
    iterator begin() const { return mesh_.points_begin(); }
    iterator end() const { return mesh_.points_end(); }
};
/// returns assignable iterator over points of mesh
PointIteratorSurfacemesh points( const Surfacemesh& mesh ) { return PointIteratorSurfacemesh( mesh ); }
/// returns assignable iterator over points of mesh
PointIteratorPolyhedron points( const Polyhedron& mesh ) { return PointIteratorPolyhedron( mesh ); }

int main( int argc, char* argv[] )
{
    Polyhedron p;
    Surfacemesh s;

    CGAL::centroid( points( s ).begin(), points( s ).end() );
    CGAL::centroid( points( p ).begin(), points( p ).end() );
    CGAL::bounding_box( points( s ).begin(), points( s ).end() );
    CGAL::bounding_box( points( p ).begin(), points( p ).end() );

    for ( Point point : points( p ) ) {
        point.x();
    }
    for ( Point point : points( s ) ) {
        point.y();
    }

    // BOOST_FOREACH macro does not work, but I don't need it

    return EXIT_SUCCESS;
}