DPL Analysis: fix combinations generator parsing in analysis task

Author: aalkin

Framework/Core/include/Framework/AnalysisManagers.h

@@ -495,16 +495,14 @@ bool initializeCache(ProcessingContext& context, T& cache)
 
 /// Combinations handling
 template <typename C, typename TG, typename... Ts>
-  requires(!is_combinations_generator<C>)
 void setGroupedCombination(C&, TG&, Ts&...)
 {
 }
 
 template <is_combinations_generator C, typename TG, typename... Ts>
-  requires((sizeof...(Ts) > 0) && (C::compatible(framework::pack<Ts...>{})))
 static void setGroupedCombination(C& comb, TG& grouping, std::tuple<Ts...>& associated)
 {
-  if constexpr (std::same_as<typename C::g_t, TG>) {
+  if constexpr (std::same_as<typename C::g_t, std::decay_t<TG>>) {
     comb.setTables(grouping, associated);
   }
 }

Framework/Core/include/Framework/GroupedCombinations.h

@@ -48,17 +48,12 @@ expressions::BindingNode getMatchingIndexNode()
 }
 
 template <typename T1, typename GroupingPolicy, typename BP, typename G, typename... As>
+  requires(sizeof...(As) > 0)
 struct GroupedCombinationsGenerator {
   using grouping_policy_t = GroupingPolicy;
   using g_t = G;
   using associated_pack_t = framework::pack<As...>;
 
-  template <typename... Ts>
-  static consteval bool compatible(framework::pack<Ts...> p)
-  {
-    return (framework::has_type<As>(p) && ...);
-  }
-
   using GroupedIteratorType = pack_to_tuple_t<interleaved_pack_t<repeated_type_pack_t<typename G::iterator, sizeof...(As)>, pack<As...>>>;
 
   struct GroupedIterator : public GroupingPolicy {
@@ -241,10 +236,11 @@ struct GroupedCombinationsGenerator {
 };
 
 template <typename T>
-concept is_combinations_generator = requires(T t) {
+concept is_combinations_generator = requires(T t, typename T::g_t const& g, pack_to_tuple_t<typename T::associated_pack_t>& a) {
   typename T::GroupedIterator;
-  &T::begin;
-  &T::end;
+  t.setTables(g, a);
+  { t.begin() } -> std::same_as<typename T::iterator>;
+  { t.end() } -> std::same_as<typename T::iterator>;
 };
 
 // Aliases for 2-particle correlations

Framework/Core/test/test_Concepts.cxx

@@ -161,4 +161,7 @@ TEST_CASE("IdentificationConcepts")
   // Expressions
   expressions::Filter f = o2::aod::track::pt > 1.0f;
   REQUIRE(expressions::is_filter<decltype(f)>);
+
+  using C = SameKindPair<aod::Collisions, aod::Tracks, ColumnBinningPolicy<aod::collision::PosZ>>;
+  REQUIRE(is_combinations_generator<C>);
 }