modified pair process function to identify both V0s alternatively

Author: Shirajum Monira

PWGCF/FemtoUniverse/Tasks/femtoUniversePairTaskTrackV0Extended.cxx

@@ -594,33 +594,33 @@ struct FemtoUniversePairTaskTrackV0Extended {
       }
     };
 
-    auto pairProcessFunc = [&](auto& p1, auto& p2) -> void {
+    auto pairProcessFunc = [&](auto& p1, auto& p2) -> bool {
       if (v0Duplicates.contains(p1.globalIndex()) || v0Duplicates.contains(p2.globalIndex()))
-        return;
+        return false;
       // Lambda invariant mass cut for p1
       if (!invMLambda(p1.mLambda(), p1.mAntiLambda()))
-        return;
+        return false;
       // Lambda invariant mass cut for p2
       if (!invMLambda(p2.mLambda(), p2.mAntiLambda()))
-        return;
+        return false;
 
       const auto& posChild1 = parts.iteratorAt(p1.globalIndex() - 2 - parts.begin().globalIndex());
       const auto& negChild1 = parts.iteratorAt(p1.globalIndex() - 1 - parts.begin().globalIndex());
       /// p1 daughters that do not pass this condition are not selected
       if constexpr (std::experimental::is_detected<hasSigma, typename PartType::iterator>::value) {
         if (!isParticleTPC(posChild1, V0ChildTable[ConfV0Selection.confV0Type1][0]) || !isParticleTPC(negChild1, V0ChildTable[ConfV0Selection.confV0Type1][1]))
-          return;
+          return false;
         if (!isParticleTOF(posChild1, V0ChildTable[ConfV0Selection.confV0Type1][0]) || !isParticleTOF(negChild1, V0ChildTable[ConfV0Selection.confV0Type1][1]))
-          return;
+          return false;
       } else {
         if ((posChild1.pidCut() & (1u << V0ChildTable[ConfV0Selection.confV0Type1][0])) == 0 || (negChild1.pidCut() & (1u << V0ChildTable[ConfV0Selection.confV0Type1][1])) == 0)
-          return;
+          return false;
         if (ConfV0Selection.confUseStrangenessTOF) {
           if (((ConfV0Selection.confV0Type1 == 0) && (p1.pidCut() & 3) != 3) || ((ConfV0Selection.confV0Type1 == 1) && (p1.pidCut() & 12) != 12) || ((ConfV0Selection.confV0Type1 == 2) && (p1.pidCut() & 48) != 48))
-            return;
+            return false;
         } else {
           if ((posChild1.pidCut() & (8u << V0ChildTable[ConfV0Selection.confV0Type1][0])) == 0 || (negChild1.pidCut() & (8u << V0ChildTable[ConfV0Selection.confV0Type1][1])) == 0)
-            return;
+            return false;
         }
       }
 
@@ -629,33 +629,34 @@ struct FemtoUniversePairTaskTrackV0Extended {
       /// p2 daughters that do not pass this condition are not selected
       if constexpr (std::experimental::is_detected<hasSigma, typename PartType::iterator>::value) {
         if (!isParticleTPC(posChild2, V0ChildTable[ConfV0Selection.confV0Type2][0]) || !isParticleTPC(negChild2, V0ChildTable[ConfV0Selection.confV0Type2][1]))
-          return;
+          return false;
         if (!isParticleTOF(posChild2, V0ChildTable[ConfV0Selection.confV0Type2][0]) || !isParticleTOF(negChild2, V0ChildTable[ConfV0Selection.confV0Type2][1]))
-          return;
+          return false;
       } else {
         if ((posChild2.pidCut() & (1u << V0ChildTable[ConfV0Selection.confV0Type2][0])) == 0 || (negChild2.pidCut() & (1u << V0ChildTable[ConfV0Selection.confV0Type2][1])) == 0)
-          return;
+          return false;
         if (ConfV0Selection.confUseStrangenessTOF) {
           if (((ConfV0Selection.confV0Type2 == 0) && (p2.pidCut() & 3) != 3) || ((ConfV0Selection.confV0Type2 == 1) && (p2.pidCut() & 12) != 12) || ((ConfV0Selection.confV0Type2 == 2) && (p2.pidCut() & 48) != 48))
-            return;
+            return false;
         } else {
           if ((posChild2.pidCut() & (8u << V0ChildTable[ConfV0Selection.confV0Type2][0])) == 0 || (negChild2.pidCut() & (8u << V0ChildTable[ConfV0Selection.confV0Type2][1])) == 0)
-            return;
+            return false;
         }
       }
 
       if (confIsCPR.value) {
         if (confRectV0V0CPR && pairCloseRejectionV0.isClosePair<true>(p1, p2, parts, magFieldTesla, femto_universe_container::EventType::same)) {
-          return;
+          return false;
         } else if (!confRectV0V0CPR && pairCloseRejectionV0.isClosePair<false>(p1, p2, parts, magFieldTesla, femto_universe_container::EventType::same)) {
-          return;
+          return false;
         }
       }
 
       if constexpr (std::is_same<PartType, FemtoRecoParticles>::value)
         sameEventCont.setPair<true>(p1, p2, multCol, confUse3D);
       else
         sameEventCont.setPair<false>(p1, p2, multCol, confUse3D);
+      return true;
     };
 
     v0Duplicates.clear();
@@ -664,7 +665,8 @@ struct FemtoUniversePairTaskTrackV0Extended {
     }
     /// Now build the combinations for V0s
     for (const auto& [p1, p2] : combinations(CombinationsStrictlyUpperIndexPolicy(groupPartsTwo, groupPartsTwo))) {
-      pairProcessFunc(p1, p2);
+      if (!pairProcessFunc(p1, p2))
+        pairProcessFunc(p2, p1);
     }
   }