Fix warning in Utilities::MPI for serial release build

diff --git a/include/deal.II/base/mpi.templates.h b/include/deal.II/base/mpi.templates.h
index 10888963672b91070792212b45c55557adfc3162..4c0ea2c82121d43551e4b2da1fd735c5c91c415f 100644 (file)
--- a/include/deal.II/base/mpi.templates.h
+++ b/include/deal.II/base/mpi.templates.h
@@ -230,7 +230,7 @@ namespace Utilities
     T
     sum(const T &t, const MPI_Comm &mpi_communicator)
     {
-      T return_value;
+      T return_value{};
       internal::all_reduce(MPI_SUM,
                            ArrayView<const T>(&t, 1),
                            mpi_communicator,
@@ -335,7 +335,7 @@ namespace Utilities
     T
     max(const T &t, const MPI_Comm &mpi_communicator)
     {
-      T return_value;
+      T return_value{};
       internal::all_reduce(MPI_MAX,
                            ArrayView<const T>(&t, 1),
                            mpi_communicator,
@@ -377,7 +377,7 @@ namespace Utilities
     T
     min(const T &t, const MPI_Comm &mpi_communicator)
     {
-      T return_value;
+      T return_value{};
       internal::all_reduce(MPI_MIN,
                            ArrayView<const T>(&t, 1),
                            mpi_communicator,