[Bf-blender-cvs] [da019efde9b] master: Cleanup: silence warnign in volume grid code

[Stephan]

Commit: da019efde9b1906322374568eb26b892818637ef
Author: Stephan
Date:   Thu Mar 19 20:28:57 2020 +0100
Branches: master
https://developer.blender.org/rBda019efde9b1906322374568eb26b892818637ef

Cleanup: silence warnign in volume grid code

Differential Revision: https://developer.blender.org/D7175

===================================================================

M	source/blender/blenkernel/intern/volume.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/volume.cc b/source/blender/blenkernel/intern/volume.cc
index b16fe3b7524..a854b7e8abd 100644
--- a/source/blender/blenkernel/intern/volume.cc
+++ b/source/blender/blenkernel/intern/volume.cc
@@ -681,7 +681,7 @@ bool BKE_volume_load(Volume *volume, Main *bmain)
   }
 
   /* Add grids read from file to own vector, filtering out any NULL pointers. */
-  for (const openvdb::GridBase::Ptr vdb_grid : vdb_grids) {
+  for (const openvdb::GridBase::Ptr &vdb_grid : vdb_grids) {
     if (vdb_grid) {
       VolumeFileCache::Entry template_entry(grids.filepath, vdb_grid);
       grids.emplace_back(template_entry);