Fix -Wconversion warnings (g++-5.3.1 Fedora 23)

Mesh_3/include/CGAL/Compact_mesh_cell_base_3.h

@@ -79,14 +79,14 @@ public:
   void set_facet_visited (const int facet)
   {
     CGAL_precondition(facet>=0 && facet <4);
-    bits_ |= (1 << facet);
+    bits_ |= char(1 << facet);
   }
 
   /// Marks \c facet as not visited
   void reset_visited (const int facet)
   {
     CGAL_precondition(facet>=0 && facet<4);
-    bits_ &= (15 & ~(1 << facet));
+    bits_ = char(bits_ & (15 & ~(1 << facet)));
   }
 
   /// Returns \c true if \c facet is marked as visited
@@ -153,7 +153,7 @@ public:
   {
     CGAL_precondition(facet>=0 && facet<4);
     char current_bits = bits_;
-    while (bits_.compare_and_swap(current_bits | (1 << facet), current_bits) != current_bits)
+    while (bits_.compare_and_swap(current_bits | char(1 << facet), current_bits) != current_bits)
     {
       current_bits = bits_;
     }
@@ -164,7 +164,9 @@ public:
   {
     CGAL_precondition(facet>=0 && facet<4);
     char current_bits = bits_;
-    while (bits_.compare_and_swap(current_bits & (15 & ~(1 << facet)), current_bits) != current_bits)
+    char mask = char(15 & ~(1 << facet));
+    char wanted_value = current_bits & mask;
+    while (bits_.compare_and_swap(wanted_value, current_bits) != current_bits)
     {
       current_bits = bits_;
     }
@@ -174,7 +176,7 @@ public:
   bool is_facet_visited (const int facet) const
   {
     CGAL_precondition(facet>=0 && facet<4);
-    return ( (bits_ & (1 << facet)) != 0 );
+    return ( (bits_ & char(1 << facet)) != 0 );
   }
 
   /// If the circumcenter is already set (circumcenter_ != NULL),

Mesh_3/include/CGAL/Gray_image_mesh_domain_3.h

@@ -118,7 +118,9 @@ private:
   Bbox_3 compute_bounding_box(const Image& im) const
   {
     return Bbox_3(-1,-1,-1,
-                  im.xdim()*im.vx()+1, im.ydim()*im.vy()+1, im.zdim()*im.vz()+1);
+                  double(im.xdim())*im.vx()+1,
+                  double(im.ydim())*im.vy()+1,
+                  double(im.zdim())*im.vz()+1);
   }
 
 private:

Mesh_3/include/CGAL/Labeled_image_mesh_domain_3.h

@@ -133,7 +133,9 @@ private:
   Bbox_3 compute_bounding_box(const Image& im) const
   {
     return Bbox_3(-1,-1,-1,
-                  im.xdim()*im.vx()+1, im.ydim()*im.vy()+1, im.zdim()*im.vz()+1);
+                  double(im.xdim())*im.vx()+1,
+                  double(im.ydim())*im.vy()+1,
+                  double(im.zdim())*im.vz()+1);
   }
 
 private:

Mesh_3/include/CGAL/Mesh_3/Implicit_to_labeled_function_wrapper.h

@@ -109,7 +109,13 @@ public:
 
   /// Constructor
   Implicit_vector_to_labeled_function_wrapper(const std::vector<Function_*>& v)
-    : function_vector_(v) {}
+    : function_vector_(v)
+  {
+    if ( v.size() < 8 )
+    {
+      CGAL_error_msg("We support at most 8 functions !");
+    }
+  }
 
   // Default copy constructor and assignment operator are ok
 
@@ -119,18 +125,13 @@ public:
   /// Operator ()
   return_type operator()(const Point_3& p, const bool = true) const
   {
-    int nb_func = static_cast<int>(function_vector_.size());
-    if ( nb_func > 8 )
-    {
-      CGAL_error_msg("We support at most 8 functions !");
-    }
-
+    const int nb_func = static_cast<int>(function_vector_.size());
     char bits = 0;
     for ( int i = 0 ; i < nb_func ; ++i )
     {
       // Insert value into bits : we compute fi(p) and insert result at
       // bit i of bits
-      bits |= ( ((*function_vector_[i])(p) < 0) << i );
+      bits = char(bits | ( ((*function_vector_[i])(p) < 0) << i ));
     }
 
     return ( static_cast<return_type>(bits) );

Mesh_3/include/CGAL/Mesh_3/Mesh_global_optimizer.h

@@ -733,7 +733,7 @@ operator()(int nb_iterations, Visitor visitor)
     //Pb with Freeze : sometimes a few vertices continue moving indefinitely
     //if the nb of moving vertices is < 1% of total nb AND does not decrease
     if(do_freeze_
-      && nb_vertices_moved < 0.005 * initial_vertices_nb
+      && nb_vertices_moved < 0.005 * double(initial_vertices_nb)
       && nb_vertices_moved == moving_vertices.size())
     {
       // we should stop because we are
@@ -1041,7 +1041,7 @@ check_convergence() const
     sum += CGAL::sqrt(*it);
   }
 
-  FT average_move = sum/big_moves_size_;/*even if set is not full, divide*/
+  FT average_move = sum/FT(big_moves_size_);/*even if set is not full, divide*/
        /*by max size so that if only 1 point moves, it goes to 0*/
 #ifdef CGAL_MESH_3_OPTIMIZER_VERBOSE
   sum_moves_ = average_move;

Mesh_3/include/CGAL/Mesh_3/Mesher_3.h

@@ -530,7 +530,7 @@ initialize()
 #  endif
       Random_points_on_sphere_3<Point> random_point(radius);
       const int NUM_PSEUDO_INFINITE_VERTICES = static_cast<int>(
-        tbb::task_scheduler_init::default_num_threads()
+        float(tbb::task_scheduler_init::default_num_threads())
         * Concurrent_mesher_config::get().num_pseudo_infinite_vertices_per_core);
       for (int i = 0 ; i < NUM_PSEUDO_INFINITE_VERTICES ; ++i, ++random_point)
         r_c3t3_.add_far_point(*random_point + center);

Mesh_3/include/CGAL/Mesh_vertex_base_3.h

@@ -147,7 +147,10 @@ public:
 
   // Sets the dimension of the lowest dimensional face of the input 3D complex
   // that contains the vertex
-  void set_dimension(const int dimension) { dimension_ = dimension; }
+  void set_dimension(const int dimension) {
+    CGAL_assertion(dimension < 4);
+    dimension_ = short(dimension);
+  }
 
   // Tells if the vertex is marked as a special protecting ball
   bool is_special() const { return dimension_ < -1; }
@@ -155,7 +158,7 @@ public:
   // Marks or unmarks the vertex as a special protecting ball
   void set_special(bool special = true) {
     if(special != (dimension_ < -1) )
-      dimension_ = -2-dimension_;
+      dimension_ = short(-2-dimension_);
   }
 
   // Returns the index of the lowest dimensional face of the input 3D complex