InDetPhysValMonitoring: Fix clang warnings.

    
Don't use references in a range-for if the object must be copied.

InnerDetector/InDetValidation/InDetPhysValMonitoring/src/InDetPhysHitDecoratorAlg.cxx

 /*
-  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 */
 
 /**
@@ -174,7 +174,7 @@ InDetPhysHitDecoratorAlg::decorateTrack(const xAOD::TrackParticle &particle,
       }
       ATH_MSG_DEBUG("Num. track states in track " << ++trackNumber << ": " << allTrackStates.size());
 
-      for (const auto& thisTrackState: allTrackStates) {
+      for (const auto thisTrackState: allTrackStates) {
         // Copy logic from InDetRttPerformance to get hits/outliers/holes
         // Variable specifying measurement type filled
         SingleResult_t thisResult(invalidResult);

InnerDetector/InDetValidation/InDetPhysValMonitoring/src/InDetPhysValMonitoringTool.cxx

@@ -300,7 +300,7 @@ InDetPhysValMonitoringTool::fillHistograms() {
   std::vector<const xAOD::TrackParticle*> selectedTracks {};
   selectedTracks.reserve(tracks->size());
   unsigned int nTrackBAT = 0, nTrackSTD = 0, nTrackANT = 0, nTrackTOT = 0;
-  for (const auto& thisTrack: *tracks) {
+  for (const auto thisTrack: *tracks) {
     //FIXME: Why is this w.r.t the primary vertex?
     const asg::AcceptData& accept = m_trackSelectionTool->accept(*thisTrack, primaryvertex);
     if (m_useTrackSelection and not accept) continue;
@@ -488,7 +488,7 @@ InDetPhysValMonitoringTool::fillHistograms() {
       "Cannot open " << m_jetContainerName <<
         " jet container or TruthParticles truth particle container. Skipping jet plots.");
   } else {
-    for (const auto& thisJet: *jets) {         // The big jets loop
+    for (const auto thisJet: *jets) {         // The big jets loop
       if (not passJetCuts(*thisJet)) {
         continue;
       }
@@ -741,7 +741,7 @@ InDetPhysValMonitoringTool::getTruthVertices() const {
       ATH_MSG_VERBOSE("Getting TruthEvents container.");
       SG::ReadHandle<xAOD::TruthEventContainer> truthEventContainer(m_truthEventName);
       if (truthEventContainer.isValid()) {
-        for (const auto& evt : *truthEventContainer) {
+        for (const auto evt : *truthEventContainer) {
           truthVtx = evt->truthVertex(0);
           if (truthVtx) {
             truthHSVertices.push_back(truthVtx);
@@ -759,7 +759,7 @@ InDetPhysValMonitoringTool::getTruthVertices() const {
       ATH_MSG_VERBOSE("Getting TruthEvents container.");
       SG::ReadHandle<xAOD::TruthPileupEventContainer> truthPileupEventContainer(m_truthPileUpEventName);
       if (truthPileupEventContainer.isValid()) {
-        for (const auto& evt : *truthPileupEventContainer) {
+        for (const auto evt : *truthPileupEventContainer) {
           truthVtx = evt->truthVertex(0);
           if (truthVtx) {
             truthPUVertices.push_back(truthVtx);

InnerDetector/InDetValidation/InDetPhysValMonitoring/util/postProcessIDPVMHistos.cxx

 /*
-  Copyright (C) 2020 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2020, 2021 CERN for the benefit of the ATLAS collaboration
 */
 
 /**
@@ -114,7 +114,7 @@ int postProcessDir(TDirectory* dir, IDPVM::ResolutionHelper & theHelper){
   // walk through all keys in this directory 
   dir->cd();
   auto keys = dir->GetListOfKeys();
-  for (const auto & key : *keys){
+  for (const auto key : *keys){
     TObject* gotIt = dir->Get(key->GetName()); 
     
     // if we encounter a directory, descend into it and repeat the process