From e2ed34d44d1b773e033a7075386c2a50f70ca7ba Mon Sep 17 00:00:00 2001
From: Anton Alkin <anton.alkin@cern.ch>
Date: Tue, 23 Jun 2026 13:46:15 +0200
Subject: [PATCH] use provided api

---
 PWGUD/Core/UDHelpers.h                   |  8 ++++----
 PWGUD/TableProducer/DGBCCandProducer.cxx | 12 ++++++------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/PWGUD/Core/UDHelpers.h b/PWGUD/Core/UDHelpers.h
index 94d356501a7..ac3c5cf8b18 100644
--- a/PWGUD/Core/UDHelpers.h
+++ b/PWGUD/Core/UDHelpers.h
@@ -130,7 +130,7 @@ T compatibleBCs(B const& bc, uint64_t const& meanBC, int const& deltaBC, T const
   // check [min,max]BC to overlap with [bcs.iteratorAt([0,bcs.size() - 1])
   if (maxBC < bcs.iteratorAt(0).globalBC() || minBC > bcs.iteratorAt(bcs.size() - 1).globalBC()) {
     LOGF(debug, "<compatibleBCs> No overlap of [%d, %d] and [%d, %d]", minBC, maxBC, bcs.iteratorAt(0).globalBC(), bcs.iteratorAt(bcs.size() - 1).globalBC());
-    return T{{bcs.asArrowTable()->Slice(0, 0)}, static_cast<uint64_t>(0)};
+    return bcs.emptySlice();
   }
 
   // find slice of BCs table with BC in [minBC, maxBC]
@@ -164,7 +164,7 @@ T compatibleBCs(B const& bc, uint64_t const& meanBC, int const& deltaBC, T const
   }
 
   // create bc slice
-  T bcslice{{bcs.asArrowTable()->Slice(minBCId, maxBCId - minBCId + 1)}, static_cast<uint64_t>(minBCId)};
+  auto bcslice = bcs.rawSlice(minBCId, maxBCId - minBCId + 1);
   bcs.copyIndexBindings(bcslice);
   LOGF(debug, "  size of slice %d", bcslice.size());
   return bcslice;
@@ -179,7 +179,7 @@ T compatibleBCs(C const& collision, int ndt, T const& bcs, int nMinBCs = 7)
 
   // return if collisions has no associated BC
   if (!collision.has_foundBC() || ndt < 0) {
-    return T{{bcs.asArrowTable()->Slice(0, 0)}, static_cast<uint64_t>(0)};
+    return bcs.emptySlice();
   }
 
   // get associated BC
@@ -220,7 +220,7 @@ T MCcompatibleBCs(F const& collision, int const& ndt, T const& bcs, int const& n
   // return if collisions has no associated BC
   if (!collision.has_foundBC()) {
     LOGF(debug, "Collision %i - no BC found!", collision.globalIndex());
-    return T{{bcs.asArrowTable()->Slice(0, 0)}, static_cast<uint64_t>(0)};
+    return bcs.emptySlice();
   }
 
   // get associated BC
diff --git a/PWGUD/TableProducer/DGBCCandProducer.cxx b/PWGUD/TableProducer/DGBCCandProducer.cxx
index eb272397af3..cf62e50c84d 100644
--- a/PWGUD/TableProducer/DGBCCandProducer.cxx
+++ b/PWGUD/TableProducer/DGBCCandProducer.cxx
@@ -468,11 +468,11 @@ struct DGBCCandProducer {
             auto fwdTracksArray = ftibcSlice.begin().fwdtrack_as<FTCs>();
             isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
           } else {
-            auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+            auto fwdTracksArray = fwdtracks.emptySlice();
             isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
           }
         } else {
-          auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+          auto fwdTracksArray = fwdtracks.emptySlice();
           isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
         }
 
@@ -514,11 +514,11 @@ struct DGBCCandProducer {
           auto fwdTracksArray = ftibcPart.begin().fwdtrack_as<FTCs>();
           isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
         } else {
-          auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+          auto fwdTracksArray = fwdtracks.emptySlice();
           isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
         }
       } else {
-        auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+        auto fwdTracksArray = fwdtracks.emptySlice();
         isDG = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
       }
 
@@ -683,11 +683,11 @@ struct DGBCCandProducer {
               auto fwdTracksArray = ftibc.fwdtrack_as<FTCs>();
               isDG2 = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
             } else {
-              auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+              auto fwdTracksArray = fwdtracks.emptySlice();
               isDG2 = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
             }
           } else {
-            auto fwdTracksArray = FTCs{{fwdtracks.asArrowTable()->Slice(0, 0)}, (uint64_t)0};
+            auto fwdTracksArray = fwdtracks.emptySlice();
             isDG2 = dgSelector.IsSelected(diffCuts, bcRange, tracksArray, fwdTracksArray);
           }