CGAL users discussion list

[Sylvain Pion <>]

Ben Supnik wrote:
> The docs for make_conforming_Delaunay_2 say that it requires 
> ConformingDelaunayTriangulationTraits_2. traits.
>
> ConformingDelaunayTriangulationTraits_2 is labeled as having "Any model 
> of Kernel concept. In particular, all CGAL kernels."
>
> But...this doesn't seem correct to me - am I right in thinking that some 
> CGAL exact pred exact construction kernels do not have sqrt?  The one I 
> was using did not, and I get a compile failure due to being unable to 
> tkae the sqrt of a number.
>
> If sqrt is indeed required and not in all kernels, is there a way to get 
> an exact predicate/exact construction kernel without one of LEDA or GMP?

Known issue (to me at least).

One way to cheat is to define a sqrt() function for the number type
that you use, and make it approximate (convert to double, use std::sqrt,
and convert back).  It might work for some/most rational number types,
and hopefully the algorithms won't break too much...

--
Sylvain Pion
INRIA Sophia-Antipolis
Geometrica Project-Team
CGAL, http://cgal.org/