From 9f51413875012c200d51d4ed26bd4ec8374217d1 Mon Sep 17 00:00:00 2001
From: Slava Krutelyov <slava77@gmail.com>
Date: Thu, 27 Sep 2018 11:09:03 -0700
Subject: [PATCH] PhotonIDValueMapProducer use auto const ref to avoid
 unnecessary object copies

---
 .../PhotonIdentification/plugins/PhotonIDValueMapProducer.cc  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/RecoEgamma/PhotonIdentification/plugins/PhotonIDValueMapProducer.cc b/RecoEgamma/PhotonIdentification/plugins/PhotonIDValueMapProducer.cc
index a8731af079deb..4885725d0d0bd 100644
--- a/RecoEgamma/PhotonIdentification/plugins/PhotonIDValueMapProducer.cc
+++ b/RecoEgamma/PhotonIdentification/plugins/PhotonIDValueMapProducer.cc
@@ -416,11 +416,11 @@ void PhotonIDValueMapProducer::getImpactParameters(
     const edm::Ptr<reco::Candidate>& candidate, const reco::Vertex& pv, float& dxy, float& dz)
 {
     if (isAOD_) {
-        auto theTrack = *static_cast<const edm::Ptr<reco::PFCandidate>>(candidate)->trackRef();
+        auto const& theTrack = *static_cast<const edm::Ptr<reco::PFCandidate>>(candidate)->trackRef();
         dxy = theTrack.dxy(pv.position());
         dz = theTrack.dz(pv.position());
     } else {
-        auto aCand = *static_cast<const edm::Ptr<pat::PackedCandidate>>(candidate);
+        auto const& aCand = *static_cast<const edm::Ptr<pat::PackedCandidate>>(candidate);
         dxy = aCand.dxy(pv.position());
         dz = aCand.dz(pv.position());
     }