void SM_io_parser<Decorator_>::print_face(SFace_handle f) const
{ // syntax: index { fclist, ivlist, loop, mark }
  out << index(f) << " { ";
  SFace_cycle_iterator it;
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_shalfedge() ) out << index(SHalfedge_handle(it)) << ' ';
  out << ", ";
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_svertex() ) out << index(SVertex_handle(it)) << ' ';
  out << ", ";
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_shalfloop() ) out << index(SHalfloop_handle(it));
  out << ", " << f->mark() << " }\n";
}
void SM_io_parser<Decorator_>::print_face(SFace_handle f) const
{  
  out << index(f) << " { ";
  SFace_cycle_iterator it;
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_shalfedge() ) out << index(SHalfedge_handle(it)) << ' ';
  out << ", ";
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_svertex() ) out << index(SVertex_handle(it)) << ' ';
  out << ", ";
  CGAL_forall_sface_cycles_of(it,f)
    if ( it.is_shalfloop() ) out << index(SHalfloop_handle(it));
  out << ", " << f->mark() << " }\n";
}