Merge pull request #5032 from lrineau/Classification-fix_warning-GF

Fix a warning

Classification/examples/Classification/gis_tutorial_example.cpp

@@ -669,7 +669,7 @@ int main (int argc, char** argv)
   }
 
   std::size_t nb_vertices
-    = std::accumulate (polylines.begin(), polylines.end(), 0,
+    = std::accumulate (polylines.begin(), polylines.end(), 0u,
                        [](std::size_t size, const std::vector<Point_3>& poly) -> std::size_t
                        { return size + poly.size(); });