From f14223bc0422aaf39326dbf1edd77906a9cc818f Mon Sep 17 00:00:00 2001
From: Matti Kortelainen <matti.kortelainen@cern.ch>
Date: Tue, 14 Mar 2023 16:54:04 +0100
Subject: [PATCH] Use std::optional to work around maybe-uninitialized warning

---
 RecoTracker/TkDetLayers/src/TIBRing.cc | 23 +++++++++++------------
 RecoTracker/TkDetLayers/src/TIBRing.h  | 10 +++++-----
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/RecoTracker/TkDetLayers/src/TIBRing.cc b/RecoTracker/TkDetLayers/src/TIBRing.cc
index 0cd5568e68f53..5057bd9a03fa5 100644
--- a/RecoTracker/TkDetLayers/src/TIBRing.cc
+++ b/RecoTracker/TkDetLayers/src/TIBRing.cc
@@ -111,16 +111,15 @@ void TIBRing::groupedCompatibleDetsV(const TrajectoryStateOnSurface& tsos,
                                      const MeasurementEstimator& est,
                                      vector<DetGroup>& result) const {
   vector<DetGroup> closestResult;
-  SubRingCrossings crossings;
-  crossings = computeCrossings(tsos, prop.propagationDirection());
-  if (!crossings.isValid_)
+  auto crossings = computeCrossings(tsos, prop.propagationDirection());
+  if (not crossings)
     return;
 
   typedef CompatibleDetToGroupAdder Adder;
-  Adder::add(*theDets[theBinFinder.binIndex(crossings.closestIndex)], tsos, prop, est, closestResult);
+  Adder::add(*theDets[theBinFinder.binIndex(crossings->closestIndex)], tsos, prop, est, closestResult);
 
   if (closestResult.empty()) {
-    Adder::add(*theDets[theBinFinder.binIndex(crossings.nextIndex)], tsos, prop, est, result);
+    Adder::add(*theDets[theBinFinder.binIndex(crossings->nextIndex)], tsos, prop, est, result);
     return;
   }
 
@@ -128,11 +127,11 @@ void TIBRing::groupedCompatibleDetsV(const TrajectoryStateOnSurface& tsos,
   float window = computeWindowSize(closestGel.det(), closestGel.trajectoryState(), est);
 
   float detWidth = closestGel.det()->surface().bounds().width();
-  if (crossings.nextDistance < detWidth + window) {
+  if (crossings->nextDistance < detWidth + window) {
     vector<DetGroup> nextResult;
-    if (Adder::add(*theDets[theBinFinder.binIndex(crossings.nextIndex)], tsos, prop, est, nextResult)) {
+    if (Adder::add(*theDets[theBinFinder.binIndex(crossings->nextIndex)], tsos, prop, est, nextResult)) {
       int crossingSide = LayerCrossingSide::barrelSide(tsos, prop);
-      if (crossings.closestIndex < crossings.nextIndex) {
+      if (crossings->closestIndex < crossings->nextIndex) {
         DetGroupMerger::orderAndMergeTwoLevels(
             std::move(closestResult), std::move(nextResult), result, theHelicity, crossingSide);
       } else {
@@ -148,7 +147,7 @@ void TIBRing::groupedCompatibleDetsV(const TrajectoryStateOnSurface& tsos,
 
   // only loop over neighbors (other than closest and next) if window is BIG
   if (window > 0.5f * detWidth) {
-    searchNeighbors(tsos, prop, est, crossings, window, result);
+    searchNeighbors(tsos, prop, est, *crossings, window, result);
   }
 }
 
@@ -194,8 +193,8 @@ void TIBRing::searchNeighbors(const TrajectoryStateOnSurface& tsos,
   }
 }
 
-TIBRing::SubRingCrossings TIBRing::computeCrossings(const TrajectoryStateOnSurface& startingState,
-                                                    PropagationDirection propDir) const {
+std::optional<TIBRing::SubRingCrossings> TIBRing::computeCrossings(const TrajectoryStateOnSurface& startingState,
+                                                                   PropagationDirection propDir) const {
   typedef HelixBarrelPlaneCrossing2OrderLocal Crossing;
   typedef MeasurementEstimator::Local2DVector Local2DVector;
 
@@ -207,7 +206,7 @@ TIBRing::SubRingCrossings TIBRing::computeCrossings(const TrajectoryStateOnSurfa
       startPos, startDir, rho, propDir, specificSurface(), HelixBarrelCylinderCrossing::bestSol);
 
   if (!cylCrossing.hasSolution())
-    return SubRingCrossings();
+    return std::nullopt;
 
   GlobalPoint cylPoint(cylCrossing.position());
   GlobalVector cylDir(cylCrossing.direction());
diff --git a/RecoTracker/TkDetLayers/src/TIBRing.h b/RecoTracker/TkDetLayers/src/TIBRing.h
index 5e44a7e11f00c..67f44d2cf07c8 100644
--- a/RecoTracker/TkDetLayers/src/TIBRing.h
+++ b/RecoTracker/TkDetLayers/src/TIBRing.h
@@ -5,6 +5,8 @@
 #include "DataFormats/GeometrySurface/interface/BoundCylinder.h"
 #include "Utilities/BinningTools/interface/PeriodicBinFinderInPhi.h"
 
+#include <optional>
+
 /** A concrete implementation for TIB rings 
  */
 
@@ -49,10 +51,8 @@ class TIBRing final : public GeometricSearchDet {
 
   // methods for groupedCompatibleDets implementation
   struct SubRingCrossings {
-    SubRingCrossings() : isValid_(false){};
-    SubRingCrossings(int ci, int ni, float nd) : isValid_(true), closestIndex(ci), nextIndex(ni), nextDistance(nd) {}
+    SubRingCrossings(int ci, int ni, float nd) : closestIndex(ci), nextIndex(ni), nextDistance(nd) {}
 
-    bool isValid_;
     int closestIndex;
     int nextIndex;
     float nextDistance;
@@ -65,8 +65,8 @@ class TIBRing final : public GeometricSearchDet {
                        float window,
                        std::vector<DetGroup>& result) const __attribute__((hot));
 
-  SubRingCrossings computeCrossings(const TrajectoryStateOnSurface& startingState, PropagationDirection propDir) const
-      __attribute__((hot));
+  std::optional<SubRingCrossings> computeCrossings(const TrajectoryStateOnSurface& startingState,
+                                                   PropagationDirection propDir) const __attribute__((hot));
 
   float computeWindowSize(const GeomDet* det,
                           const TrajectoryStateOnSurface& tsos,