save a copy of the locally owned DoFs IndexSet and use a reference instead

diff --git a/source/dofs/dof_renumbering.cc b/source/dofs/dof_renumbering.cc
index 03a4f8bd3575b738e2bfd5d238d1a3afd4f6acfd..9ea1a95e33b1e04e558584f4251d0ed6bfb0dde1 100644 (file)
--- a/source/dofs/dof_renumbering.cc
+++ b/source/dofs/dof_renumbering.cc
@@ -410,8 +410,8 @@ namespace DoFRenumbering
     //
     // note that if constraints are not requested, then the 'constraints'
     // object will be empty and using it has no effect
-    IndexSet       locally_relevant_dofs;
-    const IndexSet locally_owned_dofs = [&]() {
+    IndexSet        locally_relevant_dofs;
+    const IndexSet &locally_owned_dofs = [&]() -> const IndexSet & {
       if (reorder_level_dofs == false)
         {
           DoFTools::extract_locally_relevant_dofs(dof_handler,