constexpr function requires even parameters to be LiteralType

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/connected_components.h

@@ -59,7 +59,7 @@ namespace internal {
     // A property map
     template <typename G>
     struct No_constraint {
-      friend constexpr bool get(No_constraint<G>, typename boost::graph_traits<G>::edge_descriptor)
+      friend bool get(No_constraint<G>, typename boost::graph_traits<G>::edge_descriptor)
       {
         return false;
       }

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

@@ -75,8 +75,8 @@ struct Ecm_bind<G, No_mark<G>, No_mark<G> >
   No_mark<G> ecm1, ecm2;
   Ecm_bind(G&, G&, const No_mark<G>&, const No_mark<G>&){}
   typedef typename boost::graph_traits<G>::edge_descriptor edge_descriptor;
-  constexpr void call_put(G&, edge_descriptor, bool) const {}
-  constexpr bool call_get(G&, edge_descriptor) const {
+  void call_put(G&, edge_descriptor, bool) const {}
+  bool call_get(G&, edge_descriptor) const {
     return false;
   }
 };

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

@@ -35,7 +35,7 @@ enum Boolean_operation_type {UNION = 0, INTERSECTION,
 template <typename G>
 struct No_mark
 {
-  friend constexpr
+  friend
   bool get(No_mark<G>,
                   typename boost::graph_traits<G>::edge_descriptor)
   {

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/repair_degeneracies.h

@@ -530,8 +530,8 @@ struct Filter_wrapper_for_cap_needle_removal<TriangleMesh, VPM, Traits, Identity
   typedef typename Graph_traits::halfedge_descriptor halfedge_descriptor;
   typedef typename Graph_traits::edge_descriptor edge_descriptor;
 
-  constexpr bool flip(halfedge_descriptor){ return true; }
-  constexpr bool collapse(edge_descriptor){ return true; }
+  bool flip(halfedge_descriptor){ return true; }
+  bool collapse(edge_descriptor){ return true; }
 };
 
 } // namespace internal

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/repair_self_intersections.h

@@ -2161,8 +2161,8 @@ remove_self_intersections_one_step(std::set<typename boost::graph_traits<Triangl
     struct Return_true
     {
       constexpr bool is_empty() const { return true; }
-      constexpr bool operator()(const std::vector<std::vector<typename GeomTraits::Point_3> >&) const { return true; }
-      constexpr bool operator()(const TriangleMesh&) const { return true; }
+      bool operator()(const std::vector<std::vector<typename GeomTraits::Point_3> >&) const { return true; }
+      bool operator()(const TriangleMesh&) const { return true; }
     };
 
     Return_true cc_envelope;
@@ -2391,7 +2391,7 @@ bool remove_self_intersections(const FaceRange& face_range,
 
   struct Return_false
   {
-    constexpr bool operator()(std::pair<face_descriptor, face_descriptor>) const { return false; }
+    bool operator()(std::pair<face_descriptor, face_descriptor>) const { return false; }
   };
 
   typedef typename internal_np::Lookup_named_param_def <

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangulate_hole.h

@@ -618,7 +618,7 @@ bool use_dt3 =
     {
       struct Always_valid
       {
-        constexpr bool operator()(const std::vector<Point>&, int,int,int) const { return true; }
+        bool operator()(const std::vector<Point>&, int,int,int) const { return true; }
       };
       Always_valid is_valid;
 

Polygon_mesh_processing/test/Polygon_mesh_processing/test_remove_caps_needles.cpp

@@ -66,7 +66,7 @@ void test_with_envelope(std::string filename, double eps)
   // first a test where nothing should be done
   struct No_modification_allowed
   {
-    constexpr bool operator()(K::Point_3, K::Point_3, K::Point_3) const { return false; }
+    bool operator()(K::Point_3, K::Point_3, K::Point_3) const { return false; }
   };
   No_modification_allowed no_modif;
   const std::size_t nbv = vertices(mesh).size();

Property_map/include/CGAL/property_map.h

@@ -46,14 +46,14 @@ struct Static_boolean_property_map
   typedef bool reference;
   typedef boost::read_write_property_map_tag category;
 
-  inline friend constexpr
+  inline friend
   value_type
   get(Static_boolean_property_map, const key_type&)
   {
     return default_value;
   }
 
-  inline friend constexpr
+  inline friend
   void
   put(Static_boolean_property_map, const key_type&, value_type)
   {}