CGAL users discussion list

[Johannes Otepka <>]

Hi Ambroise,
I have seen these multiple definition errors on my windows maschine too. 
The problem is that the functions
VRML_2_ostream& operator<<(VRML_2_ostream& os, const char* s)
VRML_2_ostream& operator<<(VRML_2_ostream& os, const double& d)
are declared (rather than defined) in VRML_2_ostream.h. So all cpp-file 
including "VRML_2_ostream.h" will show up this multiple definition problem.

solution: make these two functions inline (inline VRML_2_ostream& 
operator<<(VRML_2_ostream& os, const char* s)....) and the problem is 
resolved.

I forgot to post the bug to the mailing list - which is done now ;-)
Cheers
  Johannes


Sylvain Pion wrote:

> Hi Ambroise,
>
> Ambroise Krebs wrote:
>
> > Hi,
> > Well, I write here as I have a problem.
> > I was using CGAL-3.1 with Linux Ubuntu Hoary and everything was fine.
> > I upgraded to Linux Ubuntu Dapper and the compiler was not recognized 
> > for CGAL-3.1, so I changed it for CGAL-3.2.1.
> > I could install it without any problem, but when I compile a project 
> > that uses it (and that worked perfectly with CGAL-3.1), I get the 
> > following error:
> >
> > .//libgeom.a(GenericObject.o): In function 
> > `CGAL::operator<<(CGAL::VRML_2_ostream&, char 
> > const*)':GenericObject.cc:(.text+0x0): multiple definition of 
> > `CGAL::operator<<(CGAL::VRML_2_ostream&, char const*)'
> > geometry_test.o:geometry_test.cc:(.text+0x0): first defined here
> > .//libgeom.a(GenericObject.o): In function 
> > `CGAL::operator<<(CGAL::VRML_2_ostream&, double 
> > const&)':GenericObject.cc:(.text+0x28): multiple definition of 
> > `CGAL::operator<<(CGAL::VRML_2_ostream&, double const&)'
> > geometry_test.o:geometry_test.cc:(.text+0x28): first defined here
> >
> > I really don't know what is wrong, did anybody else met this kind of 
> > problem before?
> > Any help would be appriciated.
>
>
> What is libgeom.a and what is GenericObject.o ?
> These do not come from CGAL, I think.
>
>
> Also, note that sometimes install_cgal says a compiler is not supported,
> while it actually works.
>
> Best,