From a12dff50c0e51be4ba2779982f81abe388684ccd Mon Sep 17 00:00:00 2001
From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Wed, 28 Mar 2018 10:40:33 +0200
Subject: [PATCH] Avoid copies clang-tidy complains about

---
 source/grid/grid_tools.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/grid/grid_tools.cc b/source/grid/grid_tools.cc
index 23ef95321d..7a8e74df85 100644
--- a/source/grid/grid_tools.cc
+++ b/source/grid/grid_tools.cc
@@ -2708,7 +2708,7 @@ next_cell:
   minimal_cell_diameter (const Triangulation<dim, spacedim> &triangulation)
   {
     double min_diameter = std::numeric_limits<double>::max();
-    for (const auto cell: triangulation.active_cell_iterators())
+    for (const auto &cell: triangulation.active_cell_iterators())
       if (!cell->is_artificial())
         min_diameter = std::min (min_diameter,
                                  cell->diameter());
@@ -2722,7 +2722,7 @@ next_cell:
   maximal_cell_diameter (const Triangulation<dim, spacedim> &triangulation)
   {
     double max_diameter = 0.;
-    for (const auto cell: triangulation.active_cell_iterators())
+    for (const auto &cell: triangulation.active_cell_iterators())
       if (!cell->is_artificial())
         max_diameter = std::max (max_diameter,
                                  cell->diameter());
-- 
2.39.5