diff --git a/Bounding_volumes/include/CGAL/Min_sphere_d.h b/Bounding_volumes/include/CGAL/Min_sphere_d.h
index 4b43821dc1d..8f4d870520c 100644
--- a/Bounding_volumes/include/CGAL/Min_sphere_d.h
+++ b/Bounding_volumes/include/CGAL/Min_sphere_d.h
@@ -181,7 +181,7 @@ public:
     
     int number_of_points() const
     {
-        return points.size();
+        return static_cast<int>(points.size());
     }
     
     int number_of_support_points() const
diff --git a/Point_set_processing_3/include/CGAL/jet_estimate_normals.h b/Point_set_processing_3/include/CGAL/jet_estimate_normals.h
index 97ac19b582a..f7f2955c1b4 100644
--- a/Point_set_processing_3/include/CGAL/jet_estimate_normals.h
+++ b/Point_set_processing_3/include/CGAL/jet_estimate_normals.h
@@ -158,7 +158,7 @@ jet_estimate_normals(
   // precondition: at least 2 nearest neighbors
   CGAL_point_set_processing_precondition(k >= 2);
 
-  long memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  std::size_t memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("  Creates KD-tree\n");
 
   InputIterator it;
@@ -173,7 +173,7 @@ jet_estimate_normals(
   }
   Tree tree(kd_tree_points.begin(), kd_tree_points.end());
 
-  /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("  Computes normals\n");
 
   // iterate over input points, compute and output normal
@@ -184,7 +184,7 @@ jet_estimate_normals(
     put(normal_pmap, it, normal); // normal_pmap[it] = normal
   }
 
-  /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("End of jet_estimate_normals()\n");
 }
 
diff --git a/Point_set_processing_3/include/CGAL/mst_orient_normals.h b/Point_set_processing_3/include/CGAL/mst_orient_normals.h
index 45f64a205fb..643783e68c7 100644
--- a/Point_set_processing_3/include/CGAL/mst_orient_normals.h
+++ b/Point_set_processing_3/include/CGAL/mst_orient_normals.h
@@ -294,7 +294,7 @@ create_riemannian_graph(
     // Number of input points
     const std::size_t num_input_points = distance(first, beyond);
 
-    long memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    std::size_t memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Creates KD-tree\n");
 
     // Instanciate a KD-tree search.
@@ -312,7 +312,7 @@ create_riemannian_graph(
     // Recover RAM
     kd_tree_points.clear();
 
-    /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Creates Riemannian Graph\n");
 
     // Iterates over input points and creates Riemannian Graph:
@@ -432,7 +432,7 @@ create_mst_graph(
     // Number of input points
     const std::size_t num_input_points = boost::num_vertices(riemannian_graph);
 
-    long memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    std::size_t memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Calls boost::prim_minimum_spanning_tree()\n");
 
     // Computes Minimum Spanning Tree.
@@ -444,7 +444,7 @@ create_mst_graph(
                                       weight_map( riemannian_graph_weight_map )
                                      .root_vertex( boost::vertex(source_point_index, riemannian_graph) ));
 
-    /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Creates MST Graph\n");
 
     // Converts predecessor map to a MST graph:
@@ -544,7 +544,7 @@ mst_orient_normals(
     // Precondition: at least 2 nearest neighbors
     CGAL_point_set_processing_precondition(k >= 2);
 
-    long memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    std::size_t memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Create Index_property_map\n");
 
     // Create a property map Iterator -> index.
@@ -579,7 +579,7 @@ mst_orient_normals(
                                            riemannian_graph,
                                            source_point);
 
-    /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("  Calls boost::breadth_first_search()\n");
 
     // Traverse the point set along the MST to propagate source_point's orientation
@@ -609,7 +609,7 @@ mst_orient_normals(
     // At this stage, we have typically 0 unoriented normals if k is large enough
     CGAL_TRACE("  => %u normals are unoriented\n", unoriented_points.size());
 
-    /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+    memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
     CGAL_TRACE("End of mst_orient_normals()\n");
 
     return first_unoriented_point;
diff --git a/Point_set_processing_3/include/CGAL/pca_estimate_normals.h b/Point_set_processing_3/include/CGAL/pca_estimate_normals.h
index 71c6852d94f..1a327e78c04 100644
--- a/Point_set_processing_3/include/CGAL/pca_estimate_normals.h
+++ b/Point_set_processing_3/include/CGAL/pca_estimate_normals.h
@@ -152,7 +152,7 @@ pca_estimate_normals(
   // precondition: at least 2 nearest neighbors
   CGAL_point_set_processing_precondition(k >= 2);
 
-  long memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  std::size_t memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("  Creates KD-tree\n");
 
   InputIterator it;
@@ -167,7 +167,7 @@ pca_estimate_normals(
   }
   Tree tree(kd_tree_points.begin(), kd_tree_points.end());
 
-  /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("  Computes normals\n");
 
   // iterate over input points, compute and output normal
@@ -178,7 +178,7 @@ pca_estimate_normals(
     put(normal_pmap, it, normal); // normal_pmap[it] = normal
   }
 
-  /*long*/ memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
+  memory = CGAL::Memory_sizer().virtual_size(); CGAL_TRACE("  %ld Mb allocated\n", memory>>20);
   CGAL_TRACE("End of pca_estimate_normals()\n");
 }
 
diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_normal_estimation_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_normal_estimation_plugin.cpp
index 2d0eaaa360a..1fee59949a1 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_normal_estimation_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_normal_estimation_plugin.cpp
@@ -132,7 +132,7 @@ void Polyhedron_demo_normal_estimation_plugin::on_actionNormalEstimation_trigger
       // Mark all normals as unoriented
       first_unoriented_point = points->begin();
 
-      long memory = CGAL::Memory_sizer().virtual_size();
+      std::size_t memory = CGAL::Memory_sizer().virtual_size();
       std::cerr << "Estimates normal direction: " << task_timer.time() << " seconds, "
                                                   << (memory>>20) << " Mb allocated"
                                                   << std::endl;
@@ -150,7 +150,7 @@ void Polyhedron_demo_normal_estimation_plugin::on_actionNormalEstimation_trigger
       // Mark all normals as unoriented
       first_unoriented_point = points->begin();
 
-      long memory = CGAL::Memory_sizer().virtual_size();
+      std::size_t memory = CGAL::Memory_sizer().virtual_size();
       std::cerr << "Estimates normal direction: " << task_timer.time() << " seconds, "
                                                   << (memory>>20) << " Mb allocated"
                                                   << std::endl;
@@ -170,7 +170,7 @@ void Polyhedron_demo_normal_estimation_plugin::on_actionNormalEstimation_trigger
                               dialog.orientationNbNeighbors());
 
     std::size_t nb_unoriented_normals = std::distance(first_unoriented_point, points->end());
-    long memory = CGAL::Memory_sizer().virtual_size();
+    std::size_t memory = CGAL::Memory_sizer().virtual_size();
     std::cerr << "Orient normals: " << nb_unoriented_normals << " point(s) with an unoriented normal are selected ("
                                     << task_timer.time() << " seconds, "
                                     << (memory>>20) << " Mb allocated)"
diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_average_spacing_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_average_spacing_plugin.cpp
index f6b6969289e..1473fd0fa62 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_average_spacing_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_average_spacing_plugin.cpp
@@ -88,7 +88,7 @@ void Polyhedron_demo_point_set_average_spacing_plugin::on_actionAverageSpacing_t
     // Print result
     Kernel::Sphere_3 bsphere = points->bounding_sphere();
     double radius = std::sqrt(bsphere.squared_radius());
-    long memory = CGAL::Memory_sizer().virtual_size();
+    std::size_t memory = CGAL::Memory_sizer().virtual_size();
     std::cerr << "Average spacing = " << average_spacing 
                                       << " = " << average_spacing/radius << " * point set radius (" 
                                       << task_timer.time() << " seconds, "
diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_outliers_removal_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_outliers_removal_plugin.cpp
index 1ac9a3ce236..e827a4776d1 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_outliers_removal_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_outliers_removal_plugin.cpp
@@ -95,7 +95,7 @@ void Polyhedron_demo_point_set_outliers_removal_plugin::on_actionOutlierRemoval_
                             removed_percentage);
 
     std::size_t nb_points_to_remove = std::distance(first_point_to_remove, points->end());
-    long memory = CGAL::Memory_sizer().virtual_size();
+    std::size_t memory = CGAL::Memory_sizer().virtual_size();
     std::cerr << "Simplification: " << nb_points_to_remove << " point(s) are selected ("
                                     << task_timer.time() << " seconds, "
                                     << (memory>>20) << " Mb allocated)"
diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_simplification_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_simplification_plugin.cpp
index 76104db70bb..b9bae59ccfa 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_simplification_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_point_set_simplification_plugin.cpp
@@ -112,7 +112,7 @@ void Polyhedron_demo_point_set_simplification_plugin::on_actionSimplify_triggere
     }
 
     std::size_t nb_points_to_remove = std::distance(first_point_to_remove, points->end());
-    long memory = CGAL::Memory_sizer().virtual_size();
+    std::size_t memory = CGAL::Memory_sizer().virtual_size();
     std::cerr << "Simplification: " << nb_points_to_remove << " point(s) are selected for removal ("
                                     << task_timer.time() << " seconds, "
                                     << (memory>>20) << " Mb allocated)"
diff --git a/STL_Extension/test/STL_Extension/test_namespaces.cpp b/STL_Extension/test/STL_Extension/test_namespaces.cpp
index bfcc8e0b0b9..8547b0f1e37 100644
--- a/STL_Extension/test/STL_Extension/test_namespaces.cpp
+++ b/STL_Extension/test/STL_Extension/test_namespaces.cpp
@@ -1,3 +1,9 @@
+#include <boost/config.hpp>
+
+#if defined(BOOST_MSVC)
+// avoid: warning C4996: 'CGAL::copy_n': was declared deprecated
+#  pragma warning(disable:4996)
+#endif
 #include <CGAL/array.h>
 #include <CGAL/tuple.h>
 #include <CGAL/algorithm.h>
diff --git a/Segment_Delaunay_graph_2/benchmark/Segment_Delaunay_graph_2/benchmark.cpp b/Segment_Delaunay_graph_2/benchmark/Segment_Delaunay_graph_2/benchmark.cpp
index 0f158930746..88c2c845920 100644
--- a/Segment_Delaunay_graph_2/benchmark/Segment_Delaunay_graph_2/benchmark.cpp
+++ b/Segment_Delaunay_graph_2/benchmark/Segment_Delaunay_graph_2/benchmark.cpp
@@ -32,6 +32,7 @@
 #  include <CGAL/Gmpq.h>
 #endif
 
+
 typedef CGAL::Simple_cartesian<double> K;
 typedef  K::Point_2 Point_2;
 
diff --git a/Surface_mesh_parameterization/include/CGAL/Parameterization_mesh_feature_extractor.h b/Surface_mesh_parameterization/include/CGAL/Parameterization_mesh_feature_extractor.h
index 350becd697a..a783d6d2eb1 100644
--- a/Surface_mesh_parameterization/include/CGAL/Parameterization_mesh_feature_extractor.h
+++ b/Surface_mesh_parameterization/include/CGAL/Parameterization_mesh_feature_extractor.h
@@ -180,7 +180,7 @@ private:
         while (add_border(tag_free,tag_done)) {}
 
         // #borders
-        m_nb_borders = m_skeleton.size();
+        m_nb_borders = static_cast<int>(m_skeleton.size());
 
         // put longest border first
         if (m_nb_borders>1)
@@ -249,7 +249,7 @@ private:
         double max = 0.0;
 
         // #borders
-        int nb = m_skeleton.size();
+        int nb = static_cast<int>(m_skeleton.size());
 
         for(int i=0;i<nb;i++)
         {
diff --git a/Surface_mesh_parameterization/include/CGAL/Taucs_matrix.h b/Surface_mesh_parameterization/include/CGAL/Taucs_matrix.h
index ece9949556a..8aecf299469 100644
--- a/Surface_mesh_parameterization/include/CGAL/Taucs_matrix.h
+++ b/Surface_mesh_parameterization/include/CGAL/Taucs_matrix.h
@@ -77,7 +77,7 @@ private:
     public:
 
         // Return the number of elements in the column
-        int size() const    { return m_values.size(); }
+      int size() const    { return static_cast<int>(m_values.size()); }
 
         // return address of column{index}
         // (NULL if coefficient does not exist).
diff --git a/Surface_reconstruction_points_3/include/CGAL/Poisson_reconstruction_function.h b/Surface_reconstruction_points_3/include/CGAL/Poisson_reconstruction_function.h
index 49ed4d36bdc..93684d81ec3 100644
--- a/Surface_reconstruction_points_3/include/CGAL/Poisson_reconstruction_function.h
+++ b/Surface_reconstruction_points_3/include/CGAL/Poisson_reconstruction_function.h
@@ -819,7 +819,7 @@ private:
       if(v->type() == Triangulation::INPUT)
         values.push_back(v->f());
 
-    int size = values.size();
+    std::size_t size = values.size();
     if(size == 0)
     {
       std::cerr << "Contouring: no input points\n";
@@ -827,7 +827,7 @@ private:
     }
 
     std::sort(values.begin(),values.end());
-    int index = size/2;
+    std::size_t index = size/2;
     // return values[size/2];
     return 0.5 * (values[index] + values[index+1]); // avoids singular cases
   }
diff --git a/Surface_reconstruction_points_3/include/CGAL/Reconstruction_triangulation_3.h b/Surface_reconstruction_points_3/include/CGAL/Reconstruction_triangulation_3.h
index 843ed208729..08a4f99e02c 100644
--- a/Surface_reconstruction_points_3/include/CGAL/Reconstruction_triangulation_3.h
+++ b/Surface_reconstruction_points_3/include/CGAL/Reconstruction_triangulation_3.h
@@ -386,7 +386,7 @@ public:
         Point_with_normal pwn(get(point_pmap,it), get(normal_pmap,it));
         points.push_back(pwn);
     }
-    int n = points.size();
+    std::size_t n = points.size();
 
     initialize_bounding_sphere();
 
diff --git a/Surface_reconstruction_points_3/include/CGAL/poisson_refine_triangulation.h b/Surface_reconstruction_points_3/include/CGAL/poisson_refine_triangulation.h
index 1438dda7679..a32e92650ac 100644
--- a/Surface_reconstruction_points_3/include/CGAL/poisson_refine_triangulation.h
+++ b/Surface_reconstruction_points_3/include/CGAL/poisson_refine_triangulation.h
@@ -229,7 +229,7 @@ unsigned int poisson_refine_triangulation(
   typedef Poisson_mesher_level<Tr, Tets_criteria, Surface, Oracle, Null_mesher_level> Refiner;
 
 
-  int nb_vertices = tr.number_of_vertices(); // get former #vertices
+  std::size_t nb_vertices = tr.number_of_vertices(); // get former #vertices
 
   // Delaunay refinement
   Tets_criteria tets_criteria(radius_edge_ratio_bound*radius_edge_ratio_bound, 
@@ -241,10 +241,10 @@ unsigned int poisson_refine_triangulation(
   refiner.scan_triangulation(); // Push bad cells to the queue
   refiner.refine(Null_mesh_visitor()); // Refine triangulation until queue is empty
 
-  int nb_vertices_added = tr.number_of_vertices() - nb_vertices;
+  nb_vertices = tr.number_of_vertices() - nb_vertices;
 
 
-  return (unsigned int) nb_vertices_added;
+  return static_cast<unsigned int>(nb_vertices);
 }
 
 /// \endcond