Add assert to connectivity.h

diff --git a/include/deal.II/grid/connectivity.h b/include/deal.II/grid/connectivity.h
index 0031386b455458082bfc97bc61e80d397f83b56d..747450b7c16f1fb4fc28758333a74597868b677d 100644 (file)
--- a/include/deal.II/grid/connectivity.h
+++ b/include/deal.II/grid/connectivity.h
@@ -1545,6 +1545,8 @@ namespace internal
     Connectivity<T>
     build_connectivity(const std::vector<CellData<dim>> &cells)
     {
+      AssertThrow(cells.size() > 0, ExcMessage("No cells have been provided!"));
+
       // vector of possible cell entity types
       std::vector<std::shared_ptr<CellTypeBase>> cell_types_impl(8);