Merge branch 'decianm-addLHCbIDsMethodToV3Tracks' into 'master'

Add LHCbIDs method to v3::Tracks

See merge request !3393

Event/TrackEvent/include/Event/Track_v3.h

@@ -197,6 +197,8 @@ namespace LHCb::Event::v3 {
     using base_t        = typename Tag::Track_t<Tracks>;
     using StateLocation = detail::StateLocation;
 
+    constexpr static auto MaxLHCbIDs = TracksInfo::MaxFTHits + TracksInfo::MaxVPHits + TracksInfo::MaxUTHits;
+
     using base_t::allocator_type;
     Tracks( TrackType trackType, LHCb::UniqueIDGenerator const& unique_id_gen,
             Zipping::ZipFamilyNumber zipIdentifier = Zipping::generateZipIdentifier(), allocator_type alloc = {} )
@@ -332,6 +334,15 @@ namespace LHCb::Event::v3 {
       }
 
       [[nodiscard, gnu::always_inline]] auto type() const { return this->container()->type(); }
+
+      // Retrieve the (sorted) set of LHCbIDs
+      [[nodiscard]] std::vector<LHCbID> lhcbIDs() const {
+        static_assert( width() == 1, "lhcbIDs() method cannot be used on vector proxies" );
+        std::vector<LHCbID> ids;
+        ids.reserve( Tracks::MaxLHCbIDs );
+        for ( auto i = 0; i < nHits().cast(); i++ ) { ids.emplace_back( lhcbID( i ).LHCbID() ); }
+        return ids;
+      }
     };
 
     template <SIMDWrapper::InstructionSet simd, LHCb::Pr::ProxyBehaviour behaviour, typename ContainerType>