CGAL users discussion list

[Andreas Fabri <>]

Hi Bernhard

Define

operator<(const PFacet_handle& f1, const PFacet_handle& f2)
{
  return &*f1 < &*f2;
}

This should work as std::set has less<T> as default comparator
which just calls operator<

andreas


Bernhard Kornberger wrote:
> Dear list!
>
> Having a Polyhedron_3 and a vector of critical vertices of it I need
> to create a unique container of all Facets containing at least one of
> the critical vertices. Something like:
>
> set<PFacet_handle> sCriticalFacets;
> for(unsigned i=0;i<criticalIndices.size();++i)
> {
>     Halfedge_around_vertex_circulator circ1,circ2;
>     circ1=circ2=vHandles[criticalIndices[i]]->vertex_begin();
>     do
>     {
>         sCriticalFacets.insert(circ1->facet());
>     } while((++circ1)!=circ2);
> }
>
> Clearly it does not work because operator< is not defined for
> the facet handle. Another idea is storing the facet_handles into
> a STL vector and calling sort and unique using a functor:
>
> class func_FacetSort
> {
>   public:
>   bool operator()(const PFacet_handle fh1,const PFacet_handle fh2) const
>   {
>     // return ???
>   }
> };
>
> func_FacetSort fSort;
> sort(vCriticalFacets.begin(),vCriticalFacets.end(),fSort);
> unique(..);
>
> ..but what should this functor return? The only thing I can imagine is
> to represent the vertices of the facets as strings and to compare them.
> But this seems dirty and moreover this part is time critical. Any ideas
> how to generate a container of facet_handles without duplicates?
>
> Thx!
> Bernhard