CGAL: Deal with CGAL_assertion(false)

Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Curve_analysis_2.h

@@ -890,7 +890,7 @@ class Curve_analysis_2 : public ::CGAL::Handle_with_policy< Rep_ > {
                 break;
             }
             default:{
-              CGAL_assertion(false); // !!! Never reached
+              CGAL_unreachable();
             }
             }
         }

Alpha_shapes_2/include/CGAL/Alpha_shapes_2/internal/Lazy_alpha_nt_2.h

@@ -212,7 +212,7 @@ class Lazy_alpha_nt_2
         exact_ = Exact_squared_radius()( to_exact(*data().p0),to_exact(*data().p1),to_exact(*data().p2) );
         break;
       default:
-        CGAL_assertion(false);
+        CGAL_unreachable();
     }
   }
 
@@ -229,7 +229,7 @@ class Lazy_alpha_nt_2
         approx_ = Approx_squared_radius()( to_approx(*data().p0),to_approx(*data().p1),to_approx(*data().p2) );
         break;
       default:
-        CGAL_assertion(false);
+        CGAL_unreachable();
     }
   }
 

Alpha_shapes_3/include/CGAL/Alpha_shapes_3/internal/Lazy_alpha_nt_3.h

@@ -224,7 +224,7 @@ class Lazy_alpha_nt_3{
         approx_ = Approx_squared_radius()( to_approx(*data().p0),to_approx(*data().p1),to_approx(*data().p2),to_approx(*data().p3) );
       break;
       default:
-        CGAL_assertion(false);
+        CGAL_unreachable();
     }
   }
 

Arrangement_on_surface_2/include/CGAL/Arr_point_location/Td_X_trapezoid.h

@@ -605,10 +605,9 @@ class Td_X_trapezoid : public Handle
     case CGAL_TD_VERTEX:
       return TD_VERTEX;
     default:
-       CGAL_assertion(false);
-       return TD_TRAPEZOID;
-    }
+       CGAL_unreachable();
     }
+  }
 
   /*! Access trapezoid type flag. */
   CGAL_TD_INLINE unsigned char type_flag() const

Cone_spanners_2/include/CGAL/Compute_cone_boundaries_2.h

@@ -91,10 +91,8 @@ class Compute_cone_boundaries_2 {
     DirectionOutputIterator operator()(const unsigned int cone_number,
                                        const Direction_2& initial_direction,
                                        DirectionOutputIterator result)  {
-        if (cone_number<2) {
-            std::cout << "The number of cones must be larger than 1!" << std::endl;
-            CGAL_assertion(false);
-        }
+
+        CGAL_assertion_msg(cone_number>1, "The number of cones must be larger than 1");
 
         *result++ = initial_direction;
 

Cone_spanners_2/include/CGAL/Construct_theta_graph_2.h

@@ -99,10 +99,7 @@ class Construct_theta_graph_2 {
                             ): cone_number(k), cones_choice(cones_selected), rays(std::vector<Direction_2>(k))
 
     {
-        if (k<2) {
-            std::cout << "The number of cones must be larger than 1!" << std::endl;
-            CGAL_assertion(false);
-        }
+        CGAL_assertion_msg(k>1, "The number of cones must be larger than 1");
 
         /* Initialize a functor, specialization will happen here depending on the kernel type to
          compute the cone boundaries either exactly or inexactly */

Cone_spanners_2/include/CGAL/Construct_yao_graph_2.h

@@ -93,10 +93,7 @@ class Construct_yao_graph_2 {
                           ): cone_number(k), cones_choice(cones_selected), rays(std::vector<Direction_2>(k))
 
     {
-        if (k<2) {
-            std::cout << "The number of cones must be larger than 1!" << std::endl;
-            CGAL_assertion(false);
-        }
+        CGAL_assertion_msg(k>1, "The number of cones must be larger than 1");
 
         /* Initialize a functor, specialization will happen here depending on the kernel type to
          compute the cone boundaries either exactly or inexactly */

Kinetic_space_partition/include/CGAL/KSP_3/Finalizer.h

@@ -414,7 +414,7 @@ class Finalizer {
       return true;
     }
 
-    CGAL_assertion(false);
+    CGAL_unreachable();
     return false;
   }
 

Kinetic_space_partition/include/CGAL/KSP_3/Intersection_graph.h

@@ -420,7 +420,7 @@ class Intersection_graph {
   }
 
   void set_crossed(const Edge_descriptor& edge, std::size_t sp_idx) {
-    CGAL_assertion(false);
+    CGAL_assertion(false);  // AF:  I am surprised that after the assert we do something
     m_graph[edge].crossed.insert(sp_idx);
   }
 };

Lab/demo/Lab/Plugins/PCA/Affine_transform_plugin.cpp

@@ -728,7 +728,7 @@ end()
       endPolygonMesh(transform_matrix);
     break;
     default:
-      CGAL_assertion(false);
+      CGAL_unreachable();
   }
 
   dockWidget->hide();

Linear_cell_complex/include/CGAL/CMap_linear_cell_complex_storages_with_index.h

@@ -191,12 +191,8 @@ namespace CGAL {
       // Allocate a dart for null_dart_descriptor
       assert(mdarts.empty()); // the compact container is empty
       Dart_index local_null_dart_descriptor = mdarts.emplace();
-      if(local_null_dart_descriptor!=0)
-      {
-        std::cerr<<"[ERROR] fatal in CMap_linear_cell_complex_storage_with_index::init_storage"
-                 <<std::endl;
-        CGAL_assertion(false);
-      }
+      CGAL_assertion_msg(local_null_dart_descriptor==0,
+                          "[ERROR] fatal in CMap_linear_cell_complex_storage_with_index::init_storage");
     }
 
     void clear_storage()

Mesh_3/include/CGAL/Mesh_3/Lloyd_move.h

@@ -100,9 +100,7 @@ class Lloyd_move
         break;
       default:
         // Should not happen
-        CGAL_assertion(false);
-        return CGAL::NULL_VECTOR;
-        break;
+        CGAL_unreachable();
     }
 
     return CGAL::NULL_VECTOR;

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/intersect_triangle_and_segment_3.h

@@ -126,8 +126,8 @@ intersection_type(
       // p sees the triangle in counterclockwise order
     return find_intersection(p,q,a,b,c,h_2,tm2,false,true);
 
-    default: // should not happen.
-      CGAL_assertion(false);
+    default:
+      CGAL_unreachable();
       return result_type(EMPTY,GT::null_halfedge(),false,false);
     }
   case NEGATIVE:
@@ -143,8 +143,8 @@ intersection_type(
       // q belongs to the triangle's supporting plane
       // p sees the triangle in clockwise order
       return find_intersection(q,p,a,b,c,h_2,tm2,false,true);
-    default: // should not happen.
-      CGAL_assertion(false);
+    default:
+      CGAL_unreachable();
       return result_type(EMPTY,GT::null_halfedge(),false,false);
     }
   case COPLANAR: // p belongs to the triangle's supporting plane
@@ -163,12 +163,12 @@ intersection_type(
         return result_type(COPLANAR_TRIANGLES,GT::null_halfedge(),true,true);
       return result_type(EMPTY,GT::null_halfedge(),true,true);
 
-    default: // should not happen.
-      CGAL_assertion(false);
+    default:
+      CGAL_unreachable();
       return result_type(EMPTY,GT::null_halfedge(),false,false);
     }
-  default: // should not happen.
-    CGAL_assertion(false);
+  default:
+    CGAL_unreachable();
     return result_type(EMPTY,GT::null_halfedge(),false,false);
   }
 }

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Isotropic_remeshing/remesh_impl.h

@@ -1940,7 +1940,7 @@ namespace internal {
         else if(is_on_mesh(h))          nb_mesh++;
         else if(is_on_border(h))        nb_border++;
         else if(is_an_isolated_constraint(h)) nb_isolated++;
-        else CGAL_assertion(false);
+        else CGAL_unreachable();
       }
       CGAL_USE(nb_border);
       CGAL_USE(nb_mesh);

Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/Two_vertices_parameterizer_3.h

@@ -205,7 +205,7 @@ class Two_vertices_parameterizer_3
       V1_max = zmax;
       break;
     default:
-      CGAL_assertion(false);
+      CGAL_unreachable();
     }
     switch (second_longest_axis)
     {
@@ -225,7 +225,7 @@ class Two_vertices_parameterizer_3
       V2_max = zmax;
       break;
     default:
-      CGAL_assertion(false);
+      CGAL_unreachable();
     }
 
     // Project onto longest bounding box axes,

TDS_2/include/CGAL/Triangulation_data_structure_2.h

@@ -1118,7 +1118,7 @@ insert_dim_up(Vertex_handle w,  bool orient)
     }
     break;
   default:
-    CGAL_assertion(false);
+    CGAL_unreachable();
     break;  }
   return v;
 }

Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/smooth_vertices.h

@@ -875,7 +875,7 @@ std::size_t smooth_vertices_on_surfaces(C3t3& c3t3,
               return CGAL::midpoint(s->source(), s->target());
             else
             {
-              CGAL_assertion(false);
+              CGAL_assertion(false); //   AF:  So are we not completely sure?
               return std::nullopt;
             }
           };

Tetrahedral_remeshing/include/CGAL/Tetrahedral_remeshing/internal/tetrahedral_remeshing_helpers.h

@@ -844,7 +844,7 @@ void set_index(typename C3t3::Vertex_handle v, const C3t3& c3t3)
   case -1://far points from concurrent Mesh_3
     break;
   default:
-    CGAL_assertion(false);
+    CGAL_unreachable();
   }
 }
 

Triangulation_2/include/CGAL/Constrained_Delaunay_triangulation_2.h

@@ -489,7 +489,7 @@ class Constrained_Delaunay_triangulation_2
       pit = propagate_conflicts(p,fh,2,pit);
       return pit;
     }
-    CGAL_assertion(false);
+    CGAL_unreachable();
     return std::make_pair(fit,eit);
   }
 

Triangulation_2/include/CGAL/Triangulation_2.h

@@ -1488,7 +1488,7 @@ insert(const Point& p, Locate_type lt, Face_handle loc, int li)
   case VERTEX:
     return loc->vertex(li);
   }
-  CGAL_assertion(false); // locate step failed
+  CGAL_unreachable(); // AF: The comment  "locate step failed" gives the idea that it may fail, but all cases are covered
   return Vertex_handle();
 }
 

Triangulation_on_sphere_2/include/CGAL/Triangulation_on_sphere_2.h

@@ -964,18 +964,12 @@ march_locate_2D(Face_handle f,
         li = (o0 == COLLINEAR) ? 2 : (o1 == COLLINEAR) ? 0 : 1;
         break;
       }
-      case 2:
+      default:   // i.e., case 2:
       {
         lt = VERTEX;
         li = (o0 != COLLINEAR) ? 2 : (o1 != COLLINEAR) ? 0 : 1;
         break;
       }
-      default:
-      {
-        // impossible
-        CGAL_assertion(false);
-        return f;
-      }
     }
 
     test_distance(t, f, lt, li);