message: get_shading_normal() returns vector<3,..>
diff: @@ -109,7 +109,7 @@ inline auto get_shading_normal(
  basic_triangle<3, T> /* */,
  normals_per_vertex_binding /* */
  )
  - -> typename HR::scalar_type
  + -> vector<3, typename HR::scalar_type>
  {
  using U = typename HR::scalar_type;
  using N = typename std::iterator_traits<Normals>::value_type;
  