CGAL users discussion list

[Eric Berberich <>]

Sterpa wrote:
> I'm trying to compile this line:
>
> if(e.target().is_at_infinity()) x = e.target().point().x()-1;
>
> and get this error:
>
> CGAL::I_Filtered_iterator<CGAL::CGALi::In_place_list_iterator<CGAL::Arr_vertex<CGAL::Arr_vertex_base<CGAL::Point_2<CGAL::Simple_cartesian<double>
> > > ,
> CGAL::Arr_halfedge_base<CGAL::Arr_linear_object_2<CGAL::Simple_cartesian<double>
> > > , CGAL::Arr_face_base>,
> std::allocator<CGAL::Arr_vertex<CGAL::Arr_vertex_base<CGAL::Point_2<CGAL::Simple_cartesian<double>
> > > ,
> CGAL::Arr_halfedge_base<CGAL::Arr_linear_object_2<CGAL::Simple_cartesian<double>
> > > , CGAL::Arr_face_base> > >,
> CGAL::Arrangement_on_surface_2<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > ,
> CGAL::Arr_unb_planar_topology_traits_2<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > ,
> CGAL::Arr_default_dcel<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > > > > ::_Is_concrete_vertex,
> CGAL::Arrangement_on_surface_2<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > ,
> CGAL::Arr_unb_planar_topology_traits_2<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > ,
> CGAL::Arr_default_dcel<CGAL::Arr_linear_traits_2<CGAL::Simple_cartesian<double>
> > > > > ::Vertex, int, std::bidirectional_iterator_tag>’ has no member named
> ‘is_at_infinity’
>
> I read that this method has been replaced by is_at_open_boundary(), but I've
> not found a way to write the equivalent statement without get some kind of
> error. How can I solve it?
>
> Thanks in advance. Best regards.-- 

Hi,

you mean a runtime error?

The point is:

  if (e.target().is_at_open_boundary())

should do the job, but

  x = e.target().point().x() - 1;

if e.target() is at an open boundary, it's not possible to access a 
point there (as there is none). In case open boundary is infinity in 
x-direction, I also doubt what "oo - 1" is. In case you consider a 
vertical asymptote check whether you can access that x-information from 
e.curve().

eriC