Flag variable maybe_unused.

diff --git a/include/deal.II/lac/affine_constraints.templates.h b/include/deal.II/lac/affine_constraints.templates.h
index 1d1343fd7dc4bdcc308743b326e9501f5c7443c6..e17c8c4410bbb3c51f9414dfec7750bb245e8b8d 100644 (file)
--- a/include/deal.II/lac/affine_constraints.templates.h
+++ b/include/deal.II/lac/affine_constraints.templates.h
@@ -317,7 +317,7 @@ namespace internal
     (void)mpi_communicator;
 #else
 
-    const unsigned int my_rank =
+    [[maybe_unused]] const unsigned int my_rank =
       Utilities::MPI::this_mpi_process(mpi_communicator);
 
     // First define a helper function that sorts and normalizes the constraints