Fix get_communicator_by_value for SUNDIALS 7

diff --git a/include/deal.II/sundials/n_vector.templates.h b/include/deal.II/sundials/n_vector.templates.h
index 3e54f4874fa911221a6ee28df6461c2805fd2369..8fe20deecce55f9f0680f1ddfb47a107d5ba1c53 100644 (file)
--- a/include/deal.II/sundials/n_vector.templates.h
+++ b/include/deal.II/sundials/n_vector.templates.h
@@ -753,7 +753,7 @@ namespace SUNDIALS
           //
           // Further, we need to cast away const here, as SUNDIALS demands the
           // communicator by value.
-          return const_cast<SUNComm>(get_mpi_communicator<VectorType>(v));
+          return const_cast<SUNComm &>(get_mpi_communicator<VectorType>(v));
         else
           return SUN_COMM_NULL;
 #    endif