CGAL users discussion list

[Bernd Gaertner <>]

Dear Martin,

the "experts" just had a round of discussions, and so far, the majority 
of them believes that it's a compiler bug. Recommended workaround: don't 
call it "distance".

Best,
Bernd.

Martin Baeker wrote:
> Dear experts,
>
> I just tried to upgrade from CGAL 3.1 to 3.3. (SuSe Linux 10.1 with
> g++ (GCC) 4.1.0 (SUSE Linux)) However, I encounter some strange
> behaviour when trying to define a function that is named "distance"
>
> #include <iostream>
> #include <CGAL/Cartesian.h>
> #include <CGAL/Point_2.h>
> #include <CGAL/MP_Float.h>
> typedef CGAL::Quotient<CGAL::MP_Float>                      NT;
> typedef CGAL::Cartesian<NT>                                 TutorialR;
> typedef CGAL::Point_2<TutorialR>                             Point;
> double distance(const Point & p, const Point & q)
> {
>   return sqrt(CGAL::to_double(squared_distance(p,q )));
> }
> int main()
> {
>   Point p1(1.,2.);
>   Point p2(2.,2.);
>   std::cout << (distance(p1,p2))  << std::endl;
>   return 0;
> }
>
> On compiling this, I get
>
> /usr/bin/g++  -Wall -frounding-math '-I/home/gecko/martin/fem/abaqus/CGAL-3.3.1/include/CGAL/config/i686_Linux-2.6_g++-4.1.0' '-I/home/gecko/martin/fem/abaqus/CGAL-3.3.1/include' -I/usr/X11/include -I/usr/lib/qt3/include -g -c -o minitest.o minitest.C 
> /usr/include/c++/4.1.0/bits/stl_iterator_base_types.h: In instantiation of »std::iterator_traits<CGAL::Point_2<CGAL::Cartesian<CGAL::Quotient<CGAL::MP_Float> > > >«:
> minitest.C:18:   instantiated from here
> /usr/include/c++/4.1.0/bits/stl_iterator_base_types.h:129: Fehler: kein Typ namens 
> »iterator_category« in »class 
> CGAL::Point_2<CGAL::Cartesian<CGAL::Quotient<CGAL::MP_Float> > >«
>
> As it seems, the function I defined is confused with the std::distance
> function, but I do not understand how this happens. If I do the same
> thing replacing the Point class with simple doubles, all is well.
>
> Any help, hints, etc are very welcome,
>
> Martin.
>
>
>
>                    Priv.-Doz. Dr. Martin Bäker
>                    Institut für Werkstoffe
>                    Technische Universität Braunschweig
>                    Langer Kamp 8
>                    38106 Braunschweig
>                    Germany
>                    Tel.: 00-49-531-391-3073
>                    Fax   00-49-531-391-3058
>                    e-mail <>-- 
> You are currently subscribed to cgal-discuss.
> To unsubscribe or access the archives, go to
> https://lists-sop.inria.fr/wws/info/cgal-discuss