CGAL users discussion list

[Michael Jäntsch <>]

 Hi Laurent,

thanks for the quick reply. I just now managed to get my stuff compiling 
and yes those are the exact two files I had to fix, by inlining the 4 
helper functions in QP_functions.h and the operator<< in QP_options.h

I was just wondering because I didn't think I had a very nonstandard 
use-case there.
Great, if it will be fixed in the next version!!!

regards
Michael



Am 09/06/2010 01:44 PM, schrieb Laurent Rineau (GeometryFactory):
> On Monday 06 September 2010 12:51:19 Michael Jäntsch wrote:
> >    Hello everyone,
> >
> > I'm new to the list as I just started using CGAL last week. I also did
> > manage to implement my quadratic program without trouble with CGAL, but
> > now I'm experiencing some trouble. Maybe someone can help me.
> >
> > Basically the linker complains about multiply defined functions, which
> > seems absolutely correct as the functions are defined in .h files (. I
> > already looked at the archives and I found a similar problem reported
> > twice:
> > https://lists-sop.inria.fr/sympa/arc/cgal-discuss/2007-01/msg00023.html
> > https://lists-sop.inria.fr/sympa/arc/cgal-discuss/2007-01/msg00020.html
> >
> > First one was in 2007 and seems to be resolved in the newer version of
> > CGAL but then the same problem appeared with different functions later.
> > Generally it seems like in CGAL there is a general problem of
> > non-template functions being defined in headers. When those headers are
> > then included in e.g multible cpp's and linked later on there will
> > always be a problem, or am I missing something??? How are other people
> > using this???
> >
> > The error can be reproduced by having two cpp's both containig #include
> > <CGAL/QP_functions.h>
> > This will cause the linker error:
> [...snip the error log]
> > I'm not sure how to resolve this. Could somebody please help me?
> > regards
> > Michael
> Hi Michael,
>
> You are right, there is a bug. That is not really a general problem of CGAL.
> We do try to avoid those issue, but only manually: our a test suite is not
> (yet) designed to catch such issues.
>
> In you case, I found out that at least two headers have that bug. That will be
> fixed in next release CGAL-3.7 (to be published before the end of September,
> if everything goes well). In attachment, you can see the two *patched* files
> to copy in include/CGAL/ as replacement of the existing ones.


--
Technische Universität München
Michael Jäntsch
Fakultät für Informatik
Robotics and Embedded Systems
Parkring 13
85748 Garching bei München
Tel: + 49.89.289.17626
Fax: + 49.89.289.17637

www6.in.tum.de