CGAL users discussion list

[Roger House <>]

Sylvain:

Thank you for your reply.  I looked at Polygon_2_edge_iterator.h, but I 
don't see where
"const" might be inserted.  Below is an excerpt from that file which 
would seem to be the place to make changes.  If you can make the 
required changes in a reply, I will see if they fix the 
iterator_distance problem.

Thank you,

Roger House


// random access iterator requirements
   Polygon_2_edge_iterator<Traits_, Container_>&
   operator+=(difference_type n) {
     first_vertex += n;
     return *this;
   }

   Polygon_2_edge_iterator<Traits_, Container_>
   operator+(difference_type n) {
     return Polygon_2_edge_iterator<Traits_, Container_>(
       container, first_vertex + n);
   }

   Polygon_2_edge_iterator<Traits_, Container_>&
   operator-=(difference_type n) {
     return (*this) -= n;
   }

   Polygon_2_edge_iterator<Traits_, Container_>
   operator-(difference_type n) {
     return Polygon_2_edge_iterator<Traits_, Container_>(
       container, first_vertex - n);
   }

   difference_type
   operator-(const Polygon_2_edge_iterator<Traits_, Container_>& a) {
     return first_vertex - a.first_vertex;
   }



Sylvain Pion wrote:
> Roger House a écrit :
> > I have not been able to get this expression to compile with MSVC++
> >
> >    iterator_distance(P.edges_begin(), I)
> >
> > where both operands are of type Polygon_2::Edge_const_iterator.  The 
> > comment
> > in the code below shows the compiler error message.  The attached file
> > contains the entire error message with all its gory details.
> >
> > It seems that two iterators of the same type which point to the same 
> > object
> > should be acceptable to iterator_distance, but perhaps I fail to 
> > understand
> > something. Any help will be appreciated.
>
> Having a quick look, it seems that some "const" are missing in
> <CGAL/Polygon_2/Polygon_2_edge_iterator.h>, in the operator+ and 
> operator-
> (and other) member functions of the Polygon_2_edge_iterator class.
> Could you try adding them and report back?