static ring_mutable_type get(mapnik::geometry::polygon<CoordinateType> & p)
{
if (p.empty()) p.resize(1);
return p[0];
}
static ring_const_type get(mapnik::geometry::polygon<CoordinateType> const& p)
{
if (p.empty()) throw std::runtime_error("Exterior ring must be initialized!");
return p[0];
}
bool operator() (mapnik::geometry::polygon<double> const& geom) const
{
return geom.empty();
}