Compilation failure with CGAL <5.5 when compiling with clang

[tamiko]

I am not sure there is much we can do about this one. But compiling deal.II with clang against CGAL versions prior to 5.5 fails:

/usr/include/CGAL/Intersections_3/internal/Tetrahedron_3_Bounded_3_do_intersect.h:55:23: error: call to 'do_intersect' is ambiguous
    const Boolean b = do_intersect(tr,
                      ^~~~~~~~~~~~
/usr/include/CGAL/Intersections_3/internal/Tetrahedron_3_Triangle_3_do_intersect.h:36:10: note: in instantiation of function template specialization 'CGAL::Intersections::internal::do_intersect_tetrahedron_bounded<CGAL::Simple_cartesian<CGAL::Mpzf>, CGAL::Triangle_3<CGAL::Simple_cartesian<CGAL::Mpzf>>>' requested here
  return do_intersect_tetrahedron_bounded(tr, tet, tr[0], k);
         ^
/usr/include/CGAL/Kernel/function_objects.h:3031:39: note: in instantiation of function template specialization 'CGAL::Intersections::internal::do_intersect<CGAL::Simple_cartesian<CGAL::Mpzf>>' requested here
    { return Intersections::internal::do_intersect(t1, t2, K()); }
                                      ^
/usr/include/CGAL/Filtered_predicate.h:111:12: note: in instantiation of function template specialization 'CGAL::CommonKernelFunctors::Do_intersect_3<CGAL::Simple_cartesian<CGAL::Mpzf>>::operator()<CGAL::Tetrahedron_3<CGAL::Simple_cartesian<CGAL::Mpzf>>, CGAL::Triangle_3<CGAL::Simple_cartesian<CGAL::Mpzf>>>' requested here
    return ep(c2e(args)...);
           ^
/usr/include/CGAL/Static_filtered_predicate.h:52:12: note: in instantiation of function template specialization 'CGAL::Filtered_predicate<CGAL::CommonKernelFunctors::Do_intersect_3<CGAL::Simple_cartesian<CGAL::Mpzf>>, CGAL::CommonKernelFunctors::Do_intersect_3<CGAL::Simple_cartesian<CGAL::Interval_nt<false>>>, CGAL::Cartesian_converter<CGAL::Type_equality_wrapper<CGAL::Cartesian_base_no_ref_count<double, CGAL::Epick>, CGAL::Epick>, CGAL::Simple_cartesian<CGAL::Mpzf>, CGAL::NT_converter<double, CGAL::Mpzf>>, CGAL::Cartesian_converter<CGAL::Type_equality_wrapper<CGAL::Cartesian_base_no_ref_count<double, CGAL::Epick>, CGAL::Epick>, CGAL::Simple_cartesian<CGAL::Interval_nt<false>>, CGAL::NT_converter<double, CGAL::Interval_nt<false>>>, true>::operator()<CGAL::Tetrahedron_3<CGAL::Epick>, CGAL::Triangle_3<CGAL::Epick>>' requested here
    return epicp(aa1.first, aa2.first);
           ^
/usr/include/CGAL/Intersections_3/Tetrahedron_3_Triangle_3.h:32:1: note: in instantiation of function template specialization 'CGAL::Static_filtered_predicate<CGAL::Simple_cartesian<CGAL::Interval_nt<false>>, CGAL::Filtered_predicate<CGAL::CommonKernelFunctors::Do_intersect_3<CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, boost::multiprecision::et_on>>>, CGAL::CommonKernelFunctors::Do_intersect_3<CGAL::Simple_cartesian<CGAL::Interval_nt<false>>>, CGAL::Exact_converter<CGAL::Epeck, CGAL::Simple_cartesian<boost::multiprecision::number<boost::multiprecision::backends::gmp_rational, boost::multiprecision::et_on>>>, CGAL::Approx_converter<CGAL::Epeck, CGAL::Simple_cartesian<CGAL::Interval_nt<false>>>, true>, CGAL::internal::Static_filters_predicates::Do_intersect_3<CGAL::Filtered_kernel_base<CGAL::Type_equality_wrapper<CGAL::Cartesian_base_no_ref_count<double, CGAL::Epick>, CGAL::Epick>>, CGAL::internal::Static_filters<CGAL::Filtered_kernel_base<CGAL::Type_equality_wrapper<CGAL::Cartesian_base_no_ref_count<double, CGAL::Epick>, CGAL::Epick>>>>>::operator()<CGAL::Tetrahedron_3<CGAL::Epeck>, CGAL::Triangle_3<CGAL::Epeck>>' requested here
CGAL_DO_INTERSECT_FUNCTION(Tetrahedron_3, Triangle_3, 3)
^
/usr/include/CGAL/Intersection_traits.h:66:25: note: expanded from macro 'CGAL_DO_INTERSECT_FUNCTION'
    return BOOST_PP_CAT(K().do_intersect_, BOOST_PP_CAT(DIM, _object()(a, b))); \
                        ^
/home/tamiko/workspace/dealii/source/cgal/intersections.cc:558:23: note: in instantiation of function template specialization 'CGAL::do_intersect<CGAL::Epeck>' requested here
            if (CGAL::do_intersect(tet, tria_quad.triangle(f)))
                      ^
/usr/include/CGAL/Intersections_3/internal/Triangle_3_Triangle_3_do_intersect.h:180:1: note: candidate function [with K = CGAL::Simple_cartesian<CGAL::Mpzf>]
do_intersect(const typename K::Triangle_3& t1,
^
/usr/include/CGAL/Boolean_set_operations_2/do_intersect.h:239:13: note: candidate function [with InputIterator = CGAL::Triangle_3<CGAL::Simple_cartesian<CGAL::Mpzf>>, Traits = const CGAL::Simple_cartesian<CGAL::Mpzf>]
inline bool do_intersect(InputIterator begin, InputIterator end, Traits& traits,
            ^

This is fixed in the newest version (5.5)

[fdrmrc]

Thanks for this check and the other patches. There's only one function triggering this (so far). It is compute_intersection_of_cells() and it requires versions >= 5.1.5.

dealii/source/cgal/intersections.cc

Line 467 in 915ca70

# if DEAL_II_CGAL_VERSION_GTE(5, 1, 5)

In 9.5, we could directly require CGAL versions >= 5.5.x for this routine(s).

[luca-heltai]

If this does not compile with CGAL < 5.5, let's just update the requirement. This is not even in 9.4, so we can be very liberal in changing compatibilities....