what is GMPXX, and is it ever used in Windows?

[Marc Glisse]

On Tue, 6 Oct 2020, Torbjörn Granlund wrote:

> CR20 <mez283em23e2ze2 at yahoo.com> writes:
>
>  GMPXX_INCLUDE_DIR-NOTFOUND
>  GMPXX_LIBRARIES-NOTFOUND
>
>  ...during a CGAL convex hull app configuration in CMAKE--and yet those
>  GMPXX header files are visible to me inside the CGAL directory:
>
>  gmpxx.h
>    C:\dev\CGAL-5.1\include\CGAL
>  GMPXX_arithmetic_kernel.h
>  C:\dev\CGAL-5.1\include\CGAL
>  gmpxx_coercion_traits.h
>  C:\dev\CGAL-5.1\include\CGAL
>
>  I don't know CMAKE and CGAL beyond my downloading them shortly before
>  this e-mail, but I managed to get Convex_hull_3 configured on CMAKE as
>  well as generated.  (I left the "CGAL_WITH_GMPXX" checkbox unticked in
>  CMAKE.)  I successfully compiled the project immediately after that.
>
>  What is GMPXX?  I'm finding little if any literature on it on the
>  internet.  However
>  https://doc.cgal.org/latest/Manual/configurationvariables.html says
>  "Under Linux, the GMPXX is also searched for,...."  Does that imply
>  that GMPXX is never searched for in CGAL for Windows (or anything for
>  Windows at all for that matter)?
>
>  Thank you in advance for any assistance/guidance.
>
> I think you contacted the wrong devs.  We're GMP and cannot keep track
> of how people integrate GMP.  Sorry.

For CGAL, you want cgal-discuss at inria.fr or stackoverflow with the [cgal] 
tag.

On windows, usually, one builds GMP using mingw, and then it can be used 
with whatever other compiler like visual studio. However, for C++, the ABI 
is less well defined. One can build GMPXX with mingw, but then it is not 
usable with visual studio. And the build system is not quite ready to 
build GMPXX directly with visual studio (there are forks and patches in 
various places on the net).

-- 
Marc Glisse