diff --git a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Arrangement_on_surface_2.txt b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Arrangement_on_surface_2.txt
index cbf0ed0b9a0..615d7afe68b 100644
--- a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Arrangement_on_surface_2.txt
+++ b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Arrangement_on_surface_2.txt
@@ -358,7 +358,7 @@ face \f$ f_2\f$. The face \f$ f_1\f$ has a more complicated structure
 as it contains two holes in its interior: One hole consists of two
 adjacent faces \f$ f_3\f$ and \f$ f_4\f$, while the other hole
 comprises of two edges. \f$ f_1\f$ also contains two isolated vertices
-\f$ u_1\f$ and \f$ u_2\f$ in its interior.
+\f$ u_1\f$ and \f$ u_2\f$ in its interior (which do not count has holes).
 \cgalFigureEnd
 <!----------------------------------------------------------------------------->
 
@@ -399,7 +399,10 @@ the `Arrangement_2` class template; their description follows.
   In this section we always use `Arr_non_caching_segment_traits_2` as
   our traits-class model in order to construct arrangements of line
   segments. In succeeding sections we also use `Arr_segment_traits_2`
-  as our traits-class model. In Section \ref aos_sec-unbounded we use
+  as our traits-class model. These two traits trade computation time
+  and storage space. The latter tores the underlying line of every
+  segment of the arrangement to expedite certain operations on the
+  arrangement segments. In Section \ref aos_sec-unbounded we use
   `Arr_linear_traits_2` to construct arrangements of linear curves
   (i.e., lines, rays, and line segments). The \ref
   PkgArrangementOnSurface2 package contains several other traits
@@ -424,7 +427,7 @@ defined in the header file `Arr_print.h`, prints out quantitative
 measures of a given arrangement. While in what follows it is used only
 by examples, it demonstrates well the use of the member functions
 \link Arrangement_on_surface_2::number_of_vertices()
-`number_of_vertices`\endlink, \link
+`number_of_vertices()`\endlink, \link
 Arrangement_on_surface_2::number_of_edges()
 `number_of_edges()`\endlink, and \link
 Arrangement_on_surface_2::number_of_faces()
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/arr_print.h b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/arr_print.h
index 9268e808eb7..bb8039a28ed 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/arr_print.h
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/arr_print.h
@@ -5,10 +5,9 @@
 // Print all neighboring vertices to a given arrangement vertex.
 //
 template<class Arrangement>
-void print_neighboring_vertices(typename Arrangement::Vertex_const_handle v)
-{
+void print_neighboring_vertices(typename Arrangement::Vertex_const_handle v) {
   if (v->is_isolated()) {
-    std::cout << "The vertex (" << v->point() << ") is isolated" << std::endl;
+    std::cout << "The vertex (" << v->point() << ") is isolated\n";
     return;
   }
 
@@ -25,8 +24,7 @@ void print_neighboring_vertices(typename Arrangement::Vertex_const_handle v)
 // boundary.
 //
 template <typename Arrangement>
-void print_ccb(typename Arrangement::Ccb_halfedge_const_circulator circ)
-{
+void print_ccb(typename Arrangement::Ccb_halfedge_const_circulator circ) {
   std::cout << "(" << circ->source()->point() << ")";
   typename Arrangement::Ccb_halfedge_const_circulator curr = circ;
   do {
@@ -41,10 +39,9 @@ void print_ccb(typename Arrangement::Ccb_halfedge_const_circulator circ)
 // Print the boundary description of an arrangement face.
 //
 template <typename Arrangement>
-void print_face(typename Arrangement::Face_const_handle f)
-{
+void print_face(typename Arrangement::Face_const_handle f) {
   // Print the outer boundary.
-  if (f->is_unbounded()) std::cout << "Unbounded face." << std::endl;
+  if (f->is_unbounded()) std::cout << "Unbounded face.\n";
   else {
     std::cout << "Outer boundary: ";
     print_ccb<Arrangement>(f->outer_ccb());
@@ -71,25 +68,24 @@ void print_face(typename Arrangement::Face_const_handle f)
 // Print the given arrangement.
 //
 template <typename Arrangement>
-void print_arrangement(const Arrangement& arr)
-{
+void print_arrangement(const Arrangement& arr) {
   CGAL_precondition(arr.is_valid());
 
   // Print the arrangement vertices.
-  std::cout << arr.number_of_vertices() << " vertices:" << std::endl;
+  std::cout << arr.number_of_vertices() << " vertices:\n";
   for (auto vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit) {
     std::cout << "(" << vit->point() << ")";
-    if (vit->is_isolated()) std::cout << " - Isolated." << std::endl;
+    if (vit->is_isolated()) std::cout << " - Isolated.\n";
     else std::cout << " - degree " << vit->degree() << std::endl;
   }
 
   // Print the arrangement edges.
-  std::cout << arr.number_of_edges() << " edges:" << std::endl;
+  std::cout << arr.number_of_edges() << " edges:\n";
   for (auto eit = arr.edges_begin(); eit != arr.edges_end(); ++eit)
-    std::cout << "[" << eit->curve() << "]" << std::endl;
+    std::cout << "[" << eit->curve() << "]\n";
 
   // Print the arrangement faces.
-  std::cout << arr.number_of_faces() << " faces:" << std::endl;
+  std::cout << arr.number_of_faces() << " faces:\n";
   for (auto fit = arr.faces_begin(); fit != arr.faces_end(); ++fit)
     print_face<Arrangement>(fit);
 }
@@ -98,9 +94,8 @@ void print_arrangement(const Arrangement& arr)
 // Print the size of the given arrangement.
 //
 template <typename Arrangement>
-void print_arrangement_size(const Arrangement& arr)
-{
-  std::cout << "The arrangement size:" << std::endl
+void print_arrangement_size(const Arrangement& arr) {
+  std::cout << "The arrangement size:\n"
             << "   |V| = " << arr.number_of_vertices()
             << ",  |E| = " << arr.number_of_edges()
             << ",  |F| = " << arr.number_of_faces() << std::endl;
@@ -110,16 +105,14 @@ void print_arrangement_size(const Arrangement& arr)
 // Print the size of the given unbounded arrangement.
 //
 template <typename Arrangement>
-void print_unbounded_arrangement_size(const Arrangement& arr)
-{
-  std::cout << "The arrangement size:" << std::endl
+void print_unbounded_arrangement_size(const Arrangement& arr) {
+  std::cout << "The arrangement size:\n"
             << "   |V| = " << arr.number_of_vertices()
             << " (plus " << arr.number_of_vertices_at_infinity()
             << " at infinity)"
             << ",  |E| = " << arr.number_of_edges()
             << ",  |F| = " << arr.number_of_faces()
-            << " (" << arr.number_of_unbounded_faces() << " unbounded)"
-            << std::endl << std::endl;
+            << " (" << arr.number_of_unbounded_faces() << " unbounded)\n\n";
 }
 
 #endif
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_dual_adapter.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_dual_adapter.cpp
index edc103195c7..dc8b6772e0b 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_dual_adapter.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_dual_adapter.cpp
@@ -48,7 +48,7 @@ int main() {
       std::cout << "face ";
       print_ccb<Ex_arrangement>(fit->outer_ccb());
     }
-    else std::cout << "the unbounded face." << std::endl;
+    else std::cout << "the unbounded face.\n";
   }
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_primal_adapter.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_primal_adapter.cpp
index 792a1a38494..7d187292199 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_primal_adapter.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bgl_primal_adapter.cpp
@@ -44,7 +44,7 @@ int main() {
 
   // Print the distance of each vertex from v0.
   std::cout << "The graph distances of the arrangement vertices from ("
-            << v0->point() << ") :" << std::endl;
+            << v0->point() << ") :\n";
   for (auto vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit)
     std::cout << "(" << vit->point() << ") at distance "
               << CGAL::to_double(dist_map[vit]) << std::endl;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
index 1bc6e5664c9..e961609d7ba 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
@@ -44,11 +44,11 @@ int main() {
 
     std::cout << "   feature above: ";
     if (CGAL::assign(hh, curr.second))
-      std::cout << '[' << hh->curve() << ']' << std::endl;
+      std::cout << '[' << hh->curve() << ']\n';
     else if (CGAL::assign(vh, curr.second))
-      std::cout << '(' << vh->point() << ')' << std::endl;
-    else if (CGAL::assign(fh, curr.second)) std::cout << "NONE" << std::endl;
-    else std::cout << "EMPTY" << std::endl;
+      std::cout << '(' << vh->point() << ')\n';
+    else if (CGAL::assign(fh, curr.second)) std::cout << "NONE\n";
+    else std::cout << "EMPTY\n";
   }
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
index 7e4a213bcca..2bb6b908475 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
@@ -46,7 +46,7 @@ int main() {
 
     // Print the vertex only if incident RED and BLUE edges were found.
     if (has_red && has_blue) {
-      std::cout << "Red intersect blue at (" << vit->point() << ")" << std::endl;
+      std::cout << "Red intersect blue at (" << vit->point() << ")\n";
     }
   }
 
@@ -64,7 +64,7 @@ int main() {
 
     // Print the edge only if it corresponds to a red-blue overlap.
     if (has_red && has_blue)
-      std::cout << "Red overlap blue at [" << eit->curve() << "]" << std::endl;
+      std::cout << "Red overlap blue at [" << eit->curve() << "]\n";
   }
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
index d6e948dd681..84b70a7f6a3 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
@@ -27,15 +27,15 @@ int main() {
 
   // Print out the curves and the number of edges each one induces.
   std::cout << "The arrangement contains "
-            << arr.number_of_curves() << " curves:" << std::endl;
+            << arr.number_of_curves() << " curves:\n";
   for (auto cit = arr.curves_begin(); cit != arr.curves_end(); ++cit)
     std::cout << "Curve [" << *cit << "] induces "
-              << arr.number_of_induced_edges(cit) << " edges." << std::endl;
+              << arr.number_of_induced_edges(cit) << " edges.\n";
 
   // Print the arrangement edges along with the list of curves that
   // induce each edge.
   std::cout << "The arrangement comprises "
-            << arr.number_of_edges() << " edges:" << std::endl;
+            << arr.number_of_edges() << " edges:\n";
   for (auto eit = arr.edges_begin(); eit != arr.edges_end(); ++eit) {
     std::cout << "[" << eit->curve() << "]. Originating curves: ";
     for (auto ocit = arr.originating_curves_begin(eit);
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
index f8df74152c3..bba1dc49650 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
@@ -51,13 +51,13 @@ int main() {
   // Copy the arrangement and print the vertices along with their colors.
   Ex_arrangement arr2 = arr;
 
-  std::cout << "The arrangement vertices:" << std::endl;
+  std::cout << "The arrangement vertices:\n";
   for (auto vit = arr2.vertices_begin(); vit != arr2.vertices_end(); ++vit) {
     std::cout << '(' << vit->point() << ") - ";
     switch (vit->data()) {
-      case BLUE  : std::cout << "BLUE."  << std::endl; break;
-      case RED   : std::cout << "RED."   << std::endl; break;
-      case WHITE : std::cout << "WHITE." << std::endl; break;
+      case BLUE  : std::cout << "BLUE.\n"; break;
+      case RED   : std::cout << "RED.\n"; break;
+      case WHITE : std::cout << "WHITE.\n"; break;
     }
   }
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
index 8ba9b0bde3d..b9ff9a31887 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
@@ -95,7 +95,7 @@ int main() {
   read(arr2, in_file, formatter);
   in_file.close();
 
-  std::cout << "The arrangement vertices: " << std::endl;
+  std::cout << "The arrangement vertices:\n";
   for (auto vit = arr2.vertices_begin(); vit != arr2.vertices_end(); ++vit)
     std::cout << '(' << vit->point() << ") - " << vit->data() << std::endl;
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_lines.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_lines.cpp
index 5e2c2fc4791..b6b4304c1a0 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_lines.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_lines.cpp
@@ -16,7 +16,7 @@ int main(int argc, char* argv[]) {
   std::ifstream in_file(filename);
 
   if (! in_file.is_open()) {
-    std::cerr << "Failed to open " << filename << "!" << std::endl;
+    std::cerr << "Failed to open " << filename << "!\n";
     return 1;
   }
 
@@ -35,14 +35,14 @@ int main(int argc, char* argv[]) {
   // Construct the dual arrangement by aggregately inserting the lines.
   Arrangement arr;
   insert(arr, dual_lines.begin(), dual_lines.end());
-  std::cout << "The dual arrangement size:" << std::endl
+  std::cout << "The dual arrangement size:\n"
             << "V = " << arr.number_of_vertices()
             << " (+ " << arr.number_of_vertices_at_infinity()
             << " at infinity)"
             << ",  E = " << arr.number_of_edges()
             << ",  F = " << arr.number_of_faces()
             << " (" << arr.number_of_unbounded_faces()
-            << " unbounded)" << std::endl;
+            << " unbounded)\n";
 
   // Look for a vertex whose degree is greater than 4.
   bool found_collinear = false;
@@ -53,11 +53,9 @@ int main(int argc, char* argv[]) {
     }
   }
   if (found_collinear)
-    std::cout << "Found at least three collinear points in the input set."
-              << std::endl;
+    std::cout << "Found at least three collinear points in the input set.\n";
   else
-    std::cout << "No three collinear points are found in the input set."
-              << std::endl;
+    std::cout << "No three collinear points are found in the input set.\n";
 
   // Pick two points from the input set, compute their midpoint and insert
   // its dual line into the arrangement.
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
index e8010d9595c..a4ff6115b6d 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
@@ -44,7 +44,7 @@ int main(int argc, char* argv[]) {
         std::cout << "Point no. " << k+1 << ": (" << points[k] << "), ";
         ++circ;
       }
-      std::cout << "are collinear." << std::endl;
+      std::cout << "are collinear.\n";
     }
   }
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation.cpp
index 0515690f82e..bf6028ba31b 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation.cpp
@@ -16,7 +16,7 @@ int main() {
   e2 = e2->twin();     // as we wish e2 to be directed from right to left
   arr.insert_at_vertices(s3, e1->target(), e2->source());
   arr.insert_at_vertices(s4, e2->target(), e1->source());
-  std::cout << "After step (a):" << std::endl;
+  std::cout << "After step (a):\n";
   print_arrangement(arr);
 
   // Step (b)---split e1 and e2 and connect the split points with a segment.
@@ -33,7 +33,7 @@ int main() {
   arr.remove_edge(e);
   arr.merge_edge(e1, e1->next(), s1);
   arr.merge_edge(e2, e2->next(), s2);
-  std::cout << std::endl << "After step (c):" << std::endl;
+  std::cout << std::endl << "After step (c):\n";
   print_arrangement(arr);
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
index 5f87c64bc5e..59c36abf614 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
@@ -32,13 +32,13 @@ int main() {
   Curve_handle handles[9];
   for (size_t k = 0; k < 9; ++k) handles[k] = insert(arr, C[k]);
 
-  std::cout << "The initial arrangement size:" << std::endl;
+  std::cout << "The initial arrangement size:\n";
   print_arrangement_size(arr);
 
   // Remove the large circle C[0].
   std::cout << "Removing C[0]: ";
   std::cout << remove_curve(arr, handles[0])
-            << " edges have been removed." << std::endl;
+            << " edges have been removed.\n";
   print_arrangement_size(arr);
 
   // Locate the point q, which should be on an edge e.
@@ -51,12 +51,12 @@ int main() {
   // Split the edge e to two edges e1 and e2;
   auto e1 = arr.split_edge(arr.non_const_handle(*e), q);
   auto e2 = e1->next();
-  std::cout << "After edge split: " << std::endl;
+  std::cout << "After edge split:\n";
   print_arrangement_size(arr);
 
   // Merge back the two split edges.
   arr.merge_edge(e1, e2);
-  std::cout << "After edge merge: " << std::endl;
+  std::cout << "After edge merge:\n";
   print_arrangement_size(arr);
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
index 83e9ed7b511..e9fa4abe29a 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
@@ -33,7 +33,7 @@ public:
 int main() {
   // Construct the arrangement containing two intersecting triangles.
   Ex_arrangement arr;
-  Face_index_observer  obs(arr);
+  Face_index_observer obs(arr);
   insert_non_intersecting_curve(arr, Segment(Point(4, 1), Point(7, 6)));
   insert_non_intersecting_curve(arr, Segment(Point(1, 6), Point(7, 6)));
   insert_non_intersecting_curve(arr, Segment(Point(4, 1), Point(1, 6)));
@@ -43,10 +43,10 @@ int main() {
 
   // Go over all arrangement faces and print the index of each face and its
   // outer boundary. The face index is stored in the data field.
-  std::cout << arr.number_of_faces() << " faces:" << std::endl;
+  std::cout << arr.number_of_faces() << " faces:\n";
   for (auto fit = arr.faces_begin(); fit != arr.faces_end(); ++fit) {
     std::cout << "Face no. " << fit->data() << ": ";
-    if (fit->is_unbounded()) std::cout << "Unbounded." << std::endl;
+    if (fit->is_unbounded()) std::cout << "Unbounded.\n";
     else {
       auto curr = fit->outer_ccb();
       std::cout << curr->source()->point();
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
index 15273581462..5756885a48e 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
@@ -40,7 +40,7 @@ int main() {
   insert(arr, Ex_polyline(ctr_curve(pts4, pts4 + 2), "D"));
 
   // Print all edges that correspond to an overlapping polyline.
-  std::cout << "The overlapping subcurves:" << std::endl;
+  std::cout << "The overlapping subcurves:\n";
   for (auto eit = arr.edges_begin(); eit != arr.edges_end(); ++eit) {
     if (eit->curve().data().length() > 1) {
       std::cout << "  [" << eit->curve() << "]  "
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/global_removal.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/global_removal.cpp
index d47b6c29379..189e3b3072c 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/global_removal.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/global_removal.cpp
@@ -15,7 +15,7 @@ int main() {
   insert(arr, Segment(Point(1, 1), Point(1, 6)));
   insert(arr, Segment(Point(5, 1), Point(5, 6)));
 
-  std::cout << "The initial arrangement:" << std::endl;
+  std::cout << "The initial arrangement:\n";
   print_arrangement(arr);
 
   // Remove e1 and its incident vertices using the function remove_edge().
@@ -27,7 +27,7 @@ int main() {
   // Remove e2 using the free remove_edge() function.
   remove_edge(arr, e2);
 
-  std::cout << "The final arrangement:" << std::endl;
+  std::cout << "The final arrangement:\n";
   print_arrangement(arr);
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
index c3bee40afed..4e38086f3ab 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
@@ -14,7 +14,7 @@ int main() {
   // Construct the arrangement.
   Arrangement arr1;
   construct_segments_arr(arr1);
-  std::cout << "Writing" << std::endl;
+  std::cout << "Writing\n";
   print_arrangement_size(arr1);
 
   // Write the arrangement to a file.
@@ -27,7 +27,7 @@ int main() {
   std::ifstream in_file("arr_ex_io.dat");
   in_file >> arr2;
   in_file.close();
-  std::cout << "Reading" << std::endl;
+  std::cout << "Reading\n";
   print_arrangement_size(arr2);
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
index 6966b3511e4..de866be3ada 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
@@ -25,7 +25,7 @@ int main() {
   Arr_with_hist arr1;
   insert(arr1, segs, segs + 6);
   std::cout << "Writing an arrangement of "
-            << arr1.number_of_curves() << " input segments:" << std::endl;
+            << arr1.number_of_curves() << " input segments:\n";
   print_arrangement_size(arr1);
 
   // Write the arrangement to a file.
@@ -39,7 +39,7 @@ int main() {
   in_file >> arr2;
   in_file.close();
   std::cout << "Read an arrangement of "
-            << arr2.number_of_curves() << " input segments:" << std::endl;
+            << arr2.number_of_curves() << " input segments:\n";
   print_arrangement_size(arr2);
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
index 28915836208..5cf95522f18 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
@@ -23,14 +23,13 @@ int main() {
   insert(arr, curves.begin(), curves.end());
 
   // Print out the size of the resulting arrangement.
-  std::cout << "Writing an arrangement of size:" << std::endl
+  std::cout << "Writing an arrangement of size:\n"
             << "   V = " << arr.number_of_vertices()
             << " (plus " << arr.number_of_vertices_at_infinity()
             << " at infinity)"
             << ",  E = " << arr.number_of_edges()
             << ",  F = " << arr.number_of_faces()
-            << " (" << arr.number_of_unbounded_faces() << " unbounded)"
-            << std::endl << std::endl;
+            << " (" << arr.number_of_unbounded_faces() << " unbounded)\n\n";
 
   // Write the arrangement to a file.
   std::ofstream out_file("arr_ex_io_unbounded.dat");
@@ -45,14 +44,13 @@ int main() {
   in_file >> arr2;
   in_file.close();
 
-  std::cout << "Read an arrangement of size:" << std::endl
+  std::cout << "Read an arrangement of size:\n"
             << "   V = " << arr2.number_of_vertices()
             << " (plus " << arr2.number_of_vertices_at_infinity()
             << " at infinity)"
             << ",  E = " << arr2.number_of_edges()
             << ",  F = " << arr2.number_of_faces()
-            << " (" << arr2.number_of_unbounded_faces() << " unbounded)"
-            << std::endl << std::endl;
+            << " (" << arr2.number_of_unbounded_faces() << " unbounded)\n\n";
 
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
index 43dc0c5cb86..d4261d64dd2 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
@@ -12,16 +12,14 @@ class My_observer : public CGAL::Arr_observer<Arrangement> {
 public:
   My_observer(Arrangement& arr) : CGAL::Arr_observer<Arrangement>(arr) {}
 
-  virtual void before_split_face(Face_handle, Halfedge_handle e)
-  {
+  virtual void before_split_face(Face_handle, Halfedge_handle e) {
     std::cout << "-> The insertion of :  [ " << e->curve()
-              << " ]  causes a face to split." << std::endl;
+              << " ]  causes a face to split.\n";
   }
 
-  virtual void before_merge_face(Face_handle, Face_handle, Halfedge_handle e)
-  {
+  virtual void before_merge_face(Face_handle, Face_handle, Halfedge_handle e) {
     std::cout << "-> The removal of :  [ " << e->curve()
-              << " ]  causes two faces to merge." << std::endl;
+              << " ]  causes two faces to merge.\n";
   }
 };
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
index 304b9826242..7fcb7a63dee 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
@@ -59,13 +59,12 @@ int main() {
   CGAL::overlay(arr1, arr2, overlay_arr, overlay_traits);
 
   // Go over the faces of the overlay arrangement and print their labels.
-  std::cout << "The overlay faces are: " << std::endl;
+  std::cout << "The overlay faces are:\n";
   for (auto res_fit = overlay_arr.faces_begin();
        res_fit != overlay_arr.faces_end(); ++res_fit)
   {
     std::cout << "  " << res_fit->data().c_str() << " ("
-              << (res_fit->is_unbounded() ? "unbounded" : "bounded")
-              << ")." << std::endl;
+              << (res_fit->is_unbounded() ? "unbounded" : "bounded") << ").\n";
   }
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
index e3c2ec59504..020320acb89 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
@@ -7,7 +7,7 @@
 #include <iostream>
 
 int main() {
-  std::cout << "Sorry, this example needs CORE ..." << std::endl;
+  std::cout << "Sorry, this example needs CORE ...\n";
   return 0;
 }
 
@@ -52,8 +52,7 @@ int main() {
   Bezier_curve B;
 
   in_file >> n_curves;
-  size_t k;
-  for (k = 0; k < n_curves; ++k) {
+  for (size_t k = 0; k < n_curves; ++k) {
     // Read the current curve (specified by its control points).
     in_file >> B;
     // convert it into x-monotone bezier curve.
@@ -71,4 +70,5 @@ int main() {
 
   return 0;
 }
+
 #endif
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
index 0bd2cae7ba9..d84ef0741a6 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
@@ -7,7 +7,7 @@
 #include <iostream>
 
 int main() {
-  std::cout << "Sorry, this example needs CORE ..." << std::endl;
+  std::cout << "Sorry, this example needs CORE ...\n";
   return 0;
 }
 
@@ -108,7 +108,7 @@ int main() {
   insert(polycurve_arrangment, polycurve_1);
   insert(polycurve_arrangment, polycurve_2);
   insert(polycurve_arrangment, x_polycurve_1);
-  std::cout << "Arrangment Statistics: " << std::endl;
+  std::cout << "Arrangment Statistics:\n";
   print_arrangement(polycurve_arrangment);
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
index 28415058b49..7513e6bff7a 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
@@ -7,7 +7,7 @@
 #include <iostream>
 
 int main() {
-  std::cout << "Sorry, this example needs CORE ..." << std::endl;
+  std::cout << "Sorry, this example needs CORE ...\n";
   return 0;
 }
 
@@ -112,13 +112,13 @@ int main() {
   Polycurve_conic_arrangment x_pc_arrangment(&traits);
   insert(x_pc_arrangment, conic_x_mono_polycurve_1);
   insert(x_pc_arrangment, conic_x_mono_polycurve_2);
-  std::cout << "X-monotone polycurve arrangement Statistics: " << std::endl;
+  std::cout << "X-monotone polycurve arrangement Statistics:\n";
   print_arrangement(x_pc_arrangment);
 
   Polycurve_conic_arrangment pc_arrangment(&traits);
   insert(pc_arrangment, conic_polycurve_1);
   insert(pc_arrangment, conic_polycurve_2);
-  std::cout << "Polycurve arrangement Statistics: " << std::endl;
+  std::cout << "Polycurve arrangement Statistics:\n";
   print_arrangement(pc_arrangment);
 
   return 0;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
index 306f38ce5ce..cca02d63210 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
@@ -19,8 +19,8 @@ int main (int argc, char* argv[]) {
   // Open the input file.
   std::ifstream in_file(filename);
   if (! in_file.is_open()) {
-    std::cerr << "Failed to open " << filename << " ..." << std::endl;
-    return (1);
+    std::cerr << "Failed to open " << filename << " ...\n";
+    return 1;
   }
 
   std::list<Segment> segments;
@@ -31,7 +31,7 @@ int main (int argc, char* argv[]) {
   CGAL::Timer timer;
 
   std::cout << "Performing aggregated insertion of "
-            << segments.size() << " segments." << std::endl;
+            << segments.size() << " segments.\n";
 
   timer.start();
   insert(arr, segments.begin(), segments.end());
@@ -39,8 +39,7 @@ int main (int argc, char* argv[]) {
 
   print_arrangement_size(arr);
 
-  std::cout << "Construction took " << timer.time()
-            << " seconds." << std::endl;
+  std::cout << "Construction took " << timer.time() << " seconds.\n";
 
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel_non_intersecting.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel_non_intersecting.cpp
index 0e3f360fe66..87b05dcbb15 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel_non_intersecting.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel_non_intersecting.cpp
@@ -25,8 +25,8 @@ int main(int argc, char* argv[]) {
   std::ifstream in_file(filename);
 
   if (! in_file.is_open()) {
-    std::cerr << "Failed to open " << filename << " ..." << std::endl;
-    return (1);
+    std::cerr << "Failed to open " << filename << " ...\n";
+    return 1;
   }
 
   // Read the segments from the file.
@@ -54,8 +54,7 @@ int main(int argc, char* argv[]) {
   Arrangement_2 arr;
   CGAL::Timer timer;
 
-  std::cout << "Performing aggregated insertion of "
-            << n << " segments." << std::endl;
+  std::cout << "Performing aggregated insertion of " << n << " segments.\n";
 
   timer.start();
   insert_non_intersecting_curves (arr, segments.begin(), segments.end());
@@ -66,8 +65,7 @@ int main(int argc, char* argv[]) {
             << ",  E = " << arr.number_of_edges()
             << ",  F = " << arr.number_of_faces() << std::endl;
 
-  std::cout << "Construction took " << timer.time()
-            << " seconds." << std::endl;
+  std::cout << "Construction took " << timer.time() << " seconds.\n";
 
   return 0;
 }
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/rational_functions_rational_coefficients.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/rational_functions_rational_coefficients.cpp
index 5eb4b14d07e..8ddab94b784 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/rational_functions_rational_coefficients.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/rational_functions_rational_coefficients.cpp
@@ -6,7 +6,7 @@
 #ifndef CGAL_USE_CORE
 #include <iostream>
 int main() {
-  std::cout << "Sorry, this example needs CORE ..." << std::endl;
+  std::cout << "Sorry, this example needs CORE ...\n";
   return 0;
 }
 
@@ -97,7 +97,7 @@ int main() {
   insert(arr, arcs.begin(), arcs.end());
 
   // Print the arrangement size.
-  std::cout << "The arrangement size:" << std::endl
+  std::cout << "The arrangement size:\n"
             << "   V = " << arr.number_of_vertices()
             << ",  E = " << arr.number_of_edges()
             << ",  F = " << arr.number_of_faces() << std::endl;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/sgm_point_location.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/sgm_point_location.cpp
index 7ed390e9f32..1ba6d9b5232 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/sgm_point_location.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/sgm_point_location.cpp
@@ -102,7 +102,7 @@ protected:
         boost::get<Face_const_handle>(&(it->second)))       // inside a face
       std::cout << "inside "
                 << (((*f)->is_unbounded()) ? "the unbounded" : "a bounded")
-                << " face." << std::endl;
+                << " face.\n";
     else if (const Halfedge_const_handle* e =
              boost::get<Halfedge_const_handle>(&(it->second))) // on an edge
       std::cout << "on an edge: " << (*e)->curve() << std::endl;
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
index bf22ac40633..e5b4c21a336 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
@@ -53,16 +53,16 @@ int main() {
     }
 
     std::cout << "   feature above: ";
-    if (! curr.second) std::cout << "EMPTY" << std::endl;
+    if (! curr.second) std::cout << "EMPTY\n";
     else {
       auto* vh = boost::get<Vertex_const_handle>(&*(curr.second));;
-      if (vh) std::cout << '(' << (*vh)->point() << ')' << std::endl;
+      if (vh) std::cout << '(' << (*vh)->point() << ')\n';
       else {
         auto* hh = boost::get<Halfedge_const_handle>(&*(curr.second));
         CGAL_assertion(hh);
         if (! (*hh)->is_fictitious())
-          std::cout << '[' << (*hh)->curve() << ']' << std::endl;
-        else std::cout << "NONE" << std::endl;
+          std::cout << '[' << (*hh)->curve() << ']\n';
+        else std::cout << "NONE\n";
       }
     }
   }