Hi Andrew,

To compile it I was forced to add some missing headers. Sorry that I didn't write it in the last email. The following code compiles for me (using Boost.Geometry develop branch) on Linux GCC 4.8 and Clang 3.4:

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

struct legacy_point
{

    double x, y;

};

BOOST_GEOMETRY_REGISTER_POINT_2D(legacy_point, double, boost::geometry::cs::cartesian, x, y)

int main()

{
   boost::geometry::model::box<legacy_point> box;
   boost::geometry::model::ring<legacy_point> ring;

   boost::geometry::model::multi_polygon< boost::geometry::model::polygon<legacy_point> > mpoly;

   boost::geometry::intersection(box, ring, mpoly);

}

If case the above doesn't help, please write which compiler do you use and which Boost version?