diff --git a/Heat_method_3/include/CGAL/Heat_method_3/internal/Intrinsic_Delaunay_triangulation_3.h b/Heat_method_3/include/CGAL/Heat_method_3/internal/Intrinsic_Delaunay_triangulation_3.h
index a33321468bf..498535a65e6 100644
--- a/Heat_method_3/include/CGAL/Heat_method_3/internal/Intrinsic_Delaunay_triangulation_3.h
+++ b/Heat_method_3/include/CGAL/Heat_method_3/internal/Intrinsic_Delaunay_triangulation_3.h
@@ -33,10 +33,13 @@
 #include <CGAL/Dynamic_property_map.h>
 #include <CGAL/squared_distance_3.h>
 #include <CGAL/number_utils.h>
+#include <CGAL/Iterator_range.h>
+#include <CGAL/Iterator_range.h>
 #include <CGAL/boost/graph/helpers.h>
 #include <CGAL/boost/graph/copy_face_graph.h>
 #include <CGAL/Heat_method_3/internal/V2V.h>
 
+
 #include <boost/iterator/transform_iterator.hpp>
 #include <boost/unordered_map.hpp>
 
@@ -537,8 +540,7 @@ num_faces(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
 
 template <typename TM,
           typename T>
-typename std::pair<typename boost::graph_traits<Intrinsic_Delaunay_triangulation_3<TM,T> >::vertex_iterator,
-                   typename boost::graph_traits<Intrinsic_Delaunay_triangulation_3<TM,T> >::vertex_iterator>
+Iterator_range<typename boost::graph_traits<Intrinsic_Delaunay_triangulation_3<TM,T> >::vertex_iterator>
 vertices(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
  {
    std::pair<typename boost::graph_traits<TM>::vertex_iterator,
@@ -546,38 +548,35 @@ vertices(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
 
   typedef typename Intrinsic_Delaunay_triangulation_3<TM,T>::Vertex_iterator_functor Fct;
   Fct fct(idt.triangle_mesh());
-  return std::make_pair(boost::make_transform_iterator(p.first, fct),
-                        boost::make_transform_iterator(p.second,fct));
+  return make_range(boost::make_transform_iterator(p.first, fct),
+                    boost::make_transform_iterator(p.second,fct));
  }
 
 
 template <typename TM,
           typename T>
-typename std::pair<typename boost::graph_traits<TM>::halfedge_iterator,
-                   typename boost::graph_traits<TM>::halfedge_iterator>
+Iterator_range<typename boost::graph_traits<TM>::halfedge_iterator>
 halfedges(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
- {
-   return halfedges(idt.triangle_mesh());
- }
+{
+  return make_range( halfedges(idt.triangle_mesh()) );
+}
 
 
 template <typename TM,
           typename T>
-typename std::pair<typename boost::graph_traits<TM>::edge_iterator,
-                   typename boost::graph_traits<TM>::edge_iterator>
+Iterator_range<typename boost::graph_traits<TM>::edge_iterator>
 edges(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
- {
-   return edges(idt.triangle_mesh());
- }
+{
+  return make_range( edges(idt.triangle_mesh()) );
+}
 
 
 template <typename TM,
           typename T>
-typename std::pair<typename boost::graph_traits<TM>::face_iterator,
-                   typename boost::graph_traits<TM>::face_iterator>
+Iterator_range<typename boost::graph_traits<TM>::face_iterator>
 faces(const Intrinsic_Delaunay_triangulation_3<TM,T>& idt)
  {
-   return faces(idt.triangle_mesh());
+   return make_range( faces(idt.triangle_mesh()) );
  }
 
 template <typename TM,