message: add nnsearch<DIMENSION> in templated meshes
diff: @@ -107,14 +107,15 @@ namespace RINGMesh {
  * @warning the NNSearch is destroyed when calling the Mesh::polygons_aabb()
  * and Mesh::cells_aabb()
  */
  - const NNSearch& vertices_nn_search() const
  + const NNSearch< DIMENSION >& vertices_nn_search() const
  {
  if( !vertices_nn_search_ ) {
  - std::vector< vec3 > vec_vertices( nb_vertices() );
  + std::vector< vecn< DIMENSION > > vec_vertices( nb_vertices() );
  for( index_t v = 0; v < nb_vertices(); ++v ) {
  vec_vertices[v] = vertex( v );
  }
  - vertices_nn_search_.reset( new NNSearch( vec_vertices, true ) );
  + vertices_nn_search_.reset(
  + new NNSearch< DIMENSION >( vec_vertices, true ) );
  }
  return *vertices_nn_search_.get();
  }
  @@ -130,7 +131,7 @@ namespace RINGMesh {
  ObjectMesh() = default;
  protected:
  - mutable std::unique_ptr< NNSearch > vertices_nn_search_;
  + mutable std::unique_ptr< NNSearch< DIMENSION > > vertices_nn_search_;
  };
  /*!
  