CGAL users discussion list

[Sylvain Pion <>]

Josip Dzolonga wrote:
> Here is the problematic code:
>
> for(std::list<Facet>::iterator iter = grown->facets->begin();
>       iter != grown->facets->end(); ++iter) {
>     Cell_handle c = (*iter).first;
>
> int index = (*iter).second;
> T.remove(c->vertex((index+1)%4));
> T.remove(c->vertex((index+2)%4));
> T.remove(c->vertex((index+3)%4));
> }
>
> Basically, I have a set of facets that I have extracted from the 
> triangulation and I want to remove them along with their points. But, 
> the T.remove lines cause segmentation faults, where T is of 
> type CGAL::Triangulation_hierarchy_3<Dt>. I get no precondition errors, 
> just a segfault.

When you remove() the first vertex, then the Cell c becomes invalid.
Then, everything can happen.  You need to memorize the Vertex_handles
first, and then remove them without refering to Cells or Facets that
may become invalid.

--
Sylvain Pion
INRIA Sophia-Antipolis
Geometrica Project-Team
CGAL, http://cgal.org/