CGAL users discussion list

[Julien Demouth <>]

Hi all,

Maybe it is a question which has already been raised (I've seen no sign 
of this in the archive of the list) but why does the CGAL::Random 
documentation page differ from its implementation ?

Is there any plan of designing a "better" Random class ? Especially 
because the actual implementation may lead to weird behaviors, as with 
the following code:

for (int i = 0 ; i < 10 ; ++i)
{
    CGAL::Triangulation_hierarchy_3 dt;
    std::vector<...> pts;
    CGAL::Random_points_on_sphere_3<...> gen;
    CGAL::copy_n (gen, 64, std::back_inserter (pts));
    dt.insert (pts.begin (), pts.end ());
    ...
}

Each loop produces the same set of points (and of course the same 
triangulation of these points). Indeed, the default constructor of 
Triangulation_hierarchy_3 creates a Random object which calls std::srand 
with a seed value of 0. It's a bit annoying and it may take some time to 
understand the problem :(

Best,
Julien