#include <CGAL/Arr_circular_line_arc_traits_2.h>
This class is a traits class for Cgal arrangements, built on top of a model of concept CircularKernel. It provides curves that can be of both types CGAL::Line_arc_2<CircularKernel> or CGAL::Circular_arc_2<CircularKernel>.
It uses the boost::variant.