Veering slightly off topic but still related to Geometry development, I've hit some hurdles with the rtree index. I could create an index of points easily but then couldn't query for the nearest neighbour of a segment. (I assume this is simply not supported at present; is it forthcoming?) So I created a ring or polygon from the segment and tried to query for the points that it covers/intersects, which is a feature listed in the documentation, but I've hit this compilation error: /usr/include/boost/geometry/algorithms/detail/overlay/get_turn_info.hpp:932:32: error: no matching function for call to ‘boost::geometry::model::referring_segment<const boost::geometry::model::d2::point_xy<double> >::referring_segment(const boost::geometry::model::point<double, 2ul, boost::geometry::cs::cartesian>&, const boost::geometry::model::point<double, 2ul, boost::geometry::cs::cartesian>&)’ This constructor for referring_segment looks OK to me, except maybe for the 'const' qualifier on the arguments? Cheers. Jeremy