The class Regular_triangulation_euclidean_traits_3<R,Weight> is designed as a default traits class for the class Regular_triangulation_3<RegularTriangulationTraits_3,TriangulationDataStructure_3>. It provides Weighted_point_3, a class for weighted points, which derives from the three dimensional point class R::Point_3.
The first argument R must be a model of the Kernel concept.
The second argument Weight of the class Regular_triangulation_euclidean_traits_3<R,Weight> is in fact optional: if is it not provided, R::RT will be used.
Note that this template class is specialized for CGAL::Exact_predicates_inexact_constructions_kernel, so that it is as if Regular_triangulation_filtered_traits_3 was used, i.e. you get filtered predicates automatically.
#include <CGAL/Regular_triangulation_euclidean_traits_3.h>

 The type for point $$p of a weighted point $$p^{(w)}=(p,w_{p}). 
 

CGAL::Regular_triangulation_filtered_traits_3.