cannot read Polygon_2 from std::istream (with CGAL::Gps_circle_segment_traits_2)
I have a "CGAL::Gps_circle_segment_traits_2" Polygon_2 that I generate and manipulate in CGAL. When trying to take the orientation of the polygon (one of the first operations I do), CGAL fails a precondition assertion. This only happens if I use the "CGAL::Simple_cartesian<double>" kernel, it works with the "CGAL::Exact_predicates_exact_constructions_kernel" kernel.
It's a very basic shape, so I was trying to investigate the issue by creating a minimal C++ example to demonstrate the problem. However, I ran into another problem: while I can export the Polygon_2 as binary, I cannot import it!
It seems to be that while General_polygon_2 has the ability to read from an istream:
The "Traits::X_monotone_curve_2" which resolves to "_X_monotone_circle_segment_2" in the case of "CGAL::Gps_circle_segment_traits_2" only supports exporting to an ostream, not importing from an istream: