void SM_io_parser<Decorator_>::debug_edge(SHalfedge_handle e) const
{
  out << index(e)
      << "(" << index(e->source()) << "," << index(e->target()) << ") "
      << index(e->twin()) << " " << index(e->incident_sface())
      << " ["<< e->mark() << "," << e->circle() << "] " << std::endl;
}
void SM_io_parser<Decorator_>::debug_edge(SHalfedge_handle e) const
{
  out << index(e)
      << "(" << index(e->source()) << "," << index(e->target()) << ") "
      << index(e->twin()) << " " << index(e->incident_sface())
      << " ["<< e->mark() << "," << e->circle() << "] " << std::endl;
}