From 1450fb217e87e0af0db7b9769873b8a03de4eb0a Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Mon, 3 Jul 2023 17:48:30 -0600
Subject: [PATCH] Use a reference argument for std::shared_ptr.

---
 include/deal.II/lac/trilinos_epetra_vector.h | 4 ++--
 source/lac/trilinos_epetra_vector.cc         | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/deal.II/lac/trilinos_epetra_vector.h b/include/deal.II/lac/trilinos_epetra_vector.h
index e131be9019..e65d0ca6f6 100644
--- a/include/deal.II/lac/trilinos_epetra_vector.h
+++ b/include/deal.II/lac/trilinos_epetra_vector.h
@@ -139,8 +139,8 @@ namespace LinearAlgebra
       import_elements(
         const ReadWriteVector<double> &V,
         VectorOperation::values        operation,
-        std::shared_ptr<const Utilities::MPI::CommunicationPatternBase>
-          communication_pattern = {});
+        const std::shared_ptr<const Utilities::MPI::CommunicationPatternBase>
+          &communication_pattern = {});
 
       /**
        * @deprecated Use import_elements() instead.
diff --git a/source/lac/trilinos_epetra_vector.cc b/source/lac/trilinos_epetra_vector.cc
index 4cc1411abd..2292e7ea76 100644
--- a/source/lac/trilinos_epetra_vector.cc
+++ b/source/lac/trilinos_epetra_vector.cc
@@ -159,8 +159,8 @@ namespace LinearAlgebra
     Vector::import_elements(
       const ReadWriteVector<double> &V,
       VectorOperation::values        operation,
-      std::shared_ptr<const Utilities::MPI::CommunicationPatternBase>
-        communication_pattern)
+      const std::shared_ptr<const Utilities::MPI::CommunicationPatternBase>
+        &communication_pattern)
     {
       // If no communication pattern is given, create one. Otherwise, use the
       // one given.
-- 
2.39.5