From e770b2b8b0018e0f9a03df2d9b18e6ab325b6fd4 Mon Sep 17 00:00:00 2001
From: Anton Alkin <anton.alkin@cern.ch>
Date: Tue, 25 Jan 2022 09:48:30 +0100
Subject: [PATCH] DPL Analysis: add template to declare index binding
 equivalence

---
 Framework/Core/include/Framework/ASoA.h       | 31 ++++++++++++++++---
 .../include/Framework/AnalysisDataModel.h     |  5 +++
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Framework/Core/include/Framework/ASoA.h b/Framework/Core/include/Framework/ASoA.h
index bee91a96c9af0..e8c18fc938586 100644
--- a/Framework/Core/include/Framework/ASoA.h
+++ b/Framework/Core/include/Framework/ASoA.h
@@ -1382,11 +1382,28 @@ using JoinBase = decltype(join(std::declval<Ts>()...));
 template <typename T1, typename T2>
 using ConcatBase = decltype(concat(std::declval<T1>(), std::declval<T2>()));
 
-template <typename T1, typename T2>
-constexpr auto is_binding_compatible_v()
+template <typename B, typename E>
+struct EquivalentIndex {
+  constexpr static bool value = false;
+};
+
+template <typename B, typename E>
+constexpr bool is_index_equivalent_v = EquivalentIndex<B, E>::value;
+
+template <typename T, typename... Os>
+constexpr bool are_bindings_compatible_v(framework::pack<Os...>&&)
+{
+  if constexpr (is_type_with_originals_v<T>) {
+    return (are_bindings_compatible_v<Os>(originals_pack_t<T>{}) || ...);
+  } else {
+    return ((std::is_same_v<T, Os> || is_index_equivalent_v<T, Os>) || ...);
+  }
+}
+
+template <typename T, typename B>
+constexpr bool is_binding_compatible_v()
 {
-  return framework::pack_size(
-           framework::intersected_pack_t<originals_pack_t<T1>, originals_pack_t<T2>>{}) > 0;
+  return are_bindings_compatible_v<T>(originals_pack_t<B>{});
 }
 
 } // namespace o2::soa
@@ -1397,6 +1414,12 @@ constexpr auto is_binding_compatible_v()
     using metadata = std::void_t<T>; \
   }
 
+#define DECLARE_EQUIVALENT_FOR_INDEX(_Base_, _Equiv_) \
+  template <>                                         \
+  struct o2::soa::EquivalentIndex<_Base_, _Equiv_> {  \
+    constexpr static bool value = true;               \
+  }
+
 #define DECLARE_SOA_COLUMN_FULL(_Name_, _Getter_, _Type_, _Label_)                                                                                                                \
   struct _Name_ : o2::soa::Column<_Type_, _Name_> {                                                                                                                               \
     static constexpr const char* mLabel = _Label_;                                                                                                                                \
diff --git a/Framework/Core/include/Framework/AnalysisDataModel.h b/Framework/Core/include/Framework/AnalysisDataModel.h
index d3b140ead20a8..c8435dbfe5a29 100644
--- a/Framework/Core/include/Framework/AnalysisDataModel.h
+++ b/Framework/Core/include/Framework/AnalysisDataModel.h
@@ -970,5 +970,10 @@ using CollisionMatchedRun3Sparse = soa::Join<Collisions, Run3MatchedSparse>::ite
 
 } // namespace aod
 
+namespace soa
+{
+DECLARE_EQUIVALENT_FOR_INDEX(aod::StoredMcParticles_000, aod::StoredMcParticles_001);
+}
+
 } // namespace o2
 #endif // O2_FRAMEWORK_ANALYSISDATAMODEL_H_