CGAL users discussion list

[Marc Glisse <>]

On Mon, 7 Mar 2016, Indranil Chowdhury wrote:

>  Thank you for your suggestion. I tried with Simple_cartesian<myDouble>
> but then I got the following error:
>
> Error    1    error C2440: 'return' : cannot convert from
> 'CGAL::Null_functor::result_type' to 'CGAL::Sign'
> E:\AnsysDev\3rdparty\CGAL\CGAL-4.4\include\CGAL\predicates\kernel_ftC2.h
> 413
>
> Here -> orientationC2(const FT &px, const FT &py,
>              const FT &qx, const FT &qy,
>              const FT &rx, const FT &ry)
> {
>  return sign_of_determinant(qx-px, qy-py, rx-px, ry-py);
> }
>
> Again I am clueless about what to do next. Did I forget to include any
> header file?

Simple_cartesian ( 
http://doc.cgal.org/latest/Kernel_23/classCGAL_1_1Simple__cartesian.html ) 
takes as argument a FieldNumberType ( 
http://doc.cgal.org/latest/Algebraic_foundations/classFieldNumberType.html 
) which in particular is RealEmbeddable ( 
http://doc.cgal.org/latest/Algebraic_foundations/classRealEmbeddable.html 
) and must therefore specialize CGAL::Real_embeddable_traits ( 
http://doc.cgal.org/latest/Algebraic_foundations/classCGAL_1_1Real__embeddable__traits.html 
). You can look for instance at CGAL/float.h (or any other number type) to 
see an example of how to teach CGAL about the properties of your number 
type.

--
Marc Glisse