LArPandoraOutput.h

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/**
 *  @file   larpandora/LArPandoraInterface/LArPandoraOutput.h
 *
 *  @brief  Helper functions for processing outputs from pandora
 *
 */
#ifndef LAR_PANDORA_OUTPUT_H
#define LAR_PANDORA_OUTPUT_H

#include "art/Persistency/Common/PtrMaker.h"
#include "lardata/Utilities/AssociationUtil.h"

namespace recob {
  class Cluster;
  class PFParticleMetadata;
}

namespace cluster { class ClusterParamsAlgBase; }

#include "larpandora/LArPandoraInterface/LArPandoraHelper.h"
#include "larpandora/LArPandoraInterface/ILArPandora.h"

#include "lardataobj/AnalysisBase/T0.h"
#include "lardataobj/RecoBase/Cluster.h"
#include "lardataobj/RecoBase/PFParticle.h"
#include "lardataobj/RecoBase/PFParticleMetadata.h"
#include "lardataobj/RecoBase/Slice.h"
#include "lardataobj/RecoBase/SpacePoint.h"
#include "lardataobj/RecoBase/Vertex.h"

#include "Api/PandoraApi.h"

namespace util {
  class GeometryUtilities;
}

#include <map>
#include <vector>

//------------------------------------------------------------------------------------------------------------------------------------------

namespace lar_pandora {

  class LArPandoraOutput {
  public:
    typedef std::vector<size_t> IdVector;
    typedef std::map<size_t, IdVector> IdToIdVectorMap;
    typedef std::map<const pandora::CaloHit*, art::Ptr<recob::Hit>> CaloHitToArtHitMap;

    typedef std::unique_ptr<std::vector<recob::PFParticle>> PFParticleCollection;
    typedef std::unique_ptr<std::vector<recob::Vertex>> VertexCollection;
    typedef std::unique_ptr<std::vector<recob::Cluster>> ClusterCollection;
    typedef std::unique_ptr<std::vector<recob::SpacePoint>> SpacePointCollection;
    typedef std::unique_ptr<std::vector<anab::T0>> T0Collection;
    typedef std::unique_ptr<std::vector<larpandoraobj::PFParticleMetadata>>
      PFParticleMetadataCollection;
    typedef std::unique_ptr<std::vector<recob::Slice>> SliceCollection;

    typedef std::unique_ptr<art::Assns<recob::PFParticle, larpandoraobj::PFParticleMetadata>>
      PFParticleToMetadataCollection;
    typedef std::unique_ptr<art::Assns<recob::PFParticle, recob::SpacePoint>>
      PFParticleToSpacePointCollection;
    typedef std::unique_ptr<art::Assns<recob::PFParticle, recob::Cluster>>
      PFParticleToClusterCollection;
    typedef std::unique_ptr<art::Assns<recob::PFParticle, recob::Vertex>>
      PFParticleToVertexCollection;
    typedef std::unique_ptr<art::Assns<recob::PFParticle, anab::T0>> PFParticleToT0Collection;
    typedef std::unique_ptr<art::Assns<recob::PFParticle, recob::Slice>>
      PFParticleToSliceCollection;

    typedef std::unique_ptr<art::Assns<recob::Cluster, recob::Hit>> ClusterToHitCollection;
    typedef std::unique_ptr<art::Assns<recob::SpacePoint, recob::Hit>> SpacePointToHitCollection;
    typedef std::unique_ptr<art::Assns<recob::Slice, recob::Hit>> SliceToHitCollection;

    /**
     *  @brief  Settings class
     */
    class Settings {
    public:
      /**
         *  @brief  Default constructor
         */
      Settings();

      /**
         *  @brief  Check the parameters and throw an exception if they are not valid
         */
      void Validate() const;

      const pandora::Pandora* m_pPrimaryPandora; ///<
      bool m_shouldRunStitching;                 ///<
      bool
        m_shouldProduceSlices; ///< Whether to produce output slices e.g. may not want to do this if only (re)processing single slices
      bool
        m_shouldProduceAllOutcomes; ///< If all outcomes should be produced in separate collections (choose false if you only require the consolidated output)
      std::string m_allOutcomesInstanceLabel; ///< The label for the instance producing all outcomes
      bool
        m_shouldProduceTestBeamInteractionVertices; ///< Whether to write the test beam interaction vertices in a separate collection
      std::string
        m_testBeamInteractionVerticesInstanceLabel; ///< The label for the test beam interaction vertices
      bool
        m_isNeutrinoRecoOnlyNoSlicing; ///< If we are running the neutrino reconstruction only with no slicing
      std::string m_hitfinderModuleLabel; ///< The hit finder module label
    };

    /**
     *  @brief  Convert the Pandora PFOs into ART clusters and write into ART event
     *
     *  @param  settings the settings
     *  @param  idToHitMap the mapping from Pandora hit ID to ART hit
     *  @param  evt the ART event
     */
    static void ProduceArtOutput(const Settings& settings,
                                 const IdToHitMap& idToHitMap,
                                 art::Event& evt);

    /**
     *  @brief  Get the address of a pandora instance with a given name
     *
     *  @param  pPrimaryPandora the primary pandora instance
     *  @param  name the name of the instance to collect
     *  @param  pPandoraInstance the output address of the pandora instance requested
     *
     *  @return if the pandora instance could be found
     */
    static bool GetPandoraInstance(const pandora::Pandora* const pPrimaryPandora,
                                   const std::string& name,
                                   const pandora::Pandora*& pPandoraInstance);

    /**
     *  @brief  Get the slice pfos - one pfo per slice
     *
     *  @param  pPrimaryPandora the primary pandora instance
     *  @param  slicePfos the output vector of slice pfos
     */
    static void GetPandoraSlices(const pandora::Pandora* const pPrimaryPandora,
                                 pandora::PfoVector& slicePfos);

    /**
     *  @brief  Check if the input pfo is an unambiguous cosmic ray
     *
     *  @param  pPfo the input pfo
     *
     *  @return if the input pfo is a clear cosmic ray
     */
    static bool IsClearCosmic(const pandora::ParticleFlowObject* const pPfo);

    /**
     *  @brief  Check if the input pfo is from a slice
     *
     *  @param  pPfo the input pfo
     *
     *  @return if the input pfo is from a slice
     */
    static bool IsFromSlice(const pandora::ParticleFlowObject* const pPfo);

    /**
     *  @brief  Get the index of the slice from which this pfo was produced
     *
     *  @param  pPfo the input pfo
     *
     *  @return the slice index
     */
    static unsigned int GetSliceIndex(const pandora::ParticleFlowObject* const pPfo);

    /**
     *  @brief  Collect the current pfos (including all downstream pfos) from the master pandora instance
     *
     *  @param  pPrimaryPandora address of master pandora instance
     *
     *  @return a sorted list of all pfos to convert to ART PFParticles
     */
    static pandora::PfoVector CollectPfos(const pandora::Pandora* const pPrimaryPandora);

    /**
     *  @brief  Collect the pfos (including all downstream pfos) from the master and daughter pandora instances
     *
     *  @param  pPrimaryPandora address of master pandora instance
     *
     *  @return a sorted list of all pfos to convert to ART PFParticles
     */
    static pandora::PfoVector CollectAllPfoOutcomes(const pandora::Pandora* const pPrimaryPandora);

    /**
     *  @brief  Collect a sorted list of all downstream pfos of an input list of parent
     *
     *  @param  parentPfoList the input list of parent pfos
     *  @param  pfoVector the sorted output list of all downstream pfos
     */
    static void CollectPfos(const pandora::PfoList& parentPfoList, pandora::PfoVector& pfoVector);

    /**
     *  @brief  Collect all vertices contained in the input pfo list
     *          Order is guaranteed provided pfoVector is ordered
     *
     *  @param  pfoVector the input list of pfos
     *  @param  pfoToVerticesMap the output mapping from pfo ID to vertex IDs (zero or one)
     *  @param  fCriteria function to extract vertex from pfo
     *
     *  @return the list of vertices collected
     */
    static pandora::VertexVector CollectVertices(
      const pandora::PfoVector& pfoVector,
      IdToIdVectorMap& pfoToVerticesMap,
      std::function<const pandora::Vertex* const(const pandora::ParticleFlowObject* const)>
        fCriteria);

    /**
     *  @brief  Collect a sorted list of all 2D clusters contained in the input pfo list
     *          Order is guaranteed provided pfoVector is ordered
     *
     *  @param  pfoVector the input list of pfos
     *  @param  pfoToClustersMap the output mapping from pfo ID to cluster IDs
     *
     *  @return the list of clusters collected
     */
    static pandora::ClusterList CollectClusters(const pandora::PfoVector& pfoVector,
                                                IdToIdVectorMap& pfoToClustersMap);

    /**
     *  @brief  Collect a sorted vector of all 3D hits in the input pfo
     *
     *  @param  pPfo the input pfo
     *  @param  caloHits the sorted output vector of 3D hits
     */
    static void Collect3DHits(const pandora::ParticleFlowObject* const pPfo,
                              pandora::CaloHitVector& caloHits);

    /**
     *  @brief  Collect a sorted list of all 3D hits contained in the input pfo list
     *          Order is guaranteed provided pfoVector is ordered
     *
     *  @param  pfoVector the input list of pfos
     *  @param  pfoToThreeDHitsMap the output mapping from pfo ID to 3D hit IDs
     *
     *  @return the list of 3D hits collected
     */
    static pandora::CaloHitList Collect3DHits(const pandora::PfoVector& pfoVector,
                                              IdToIdVectorMap& pfoToThreeDHitsMap);

    /**
     *  @brief  Find the index of an input object in an input list. Throw an exception if it doesn't exist
     *
     *  @param  pT the input object for which the ID should be found
     *  @param  tList a list of objects of type pT to query
     *
     *  @return the ID of the input object
     */
    template <typename T>
    static size_t GetId(const T* const pT, const std::list<const T*>& tList);

    /**
     *  @brief  Find the index of an input object in an input vector. Throw an exception if it doesn't exist
     *
     *  @param  pT the input object for which the ID should be found
     *  @param  tVector a list of objects of type pT to query
     *
     *  @return the ID of the input object
     */
    template <typename T>
    static size_t GetId(const T* const pT, const std::vector<const T*>& tVector);

    /**
     *  @brief  Collect all 2D and 3D hits that were used / produced in the reconstruction and map them to their corresponding ART hit
     *
     *  @param  clusterList input list of all 2D clusters to be output
     *  @param  threeDHitList input list of all 3D hits to be output (as spacepoints)
     *  @param  idToHitMap input mapping from pandora hit ID to ART hit
     *  @param  pandoraHitToArtHitMap output mapping from pandora hit to ART hit
     */
    static void GetPandoraToArtHitMap(const pandora::ClusterList& clusterList,
                                      const pandora::CaloHitList& threeDHitList,
                                      const IdToHitMap& idToHitMap,
                                      CaloHitToArtHitMap& pandoraHitToArtHitMap);

    /**
     *  @brief  Look up ART hit from an input Pandora hit
     *
     *  @param  idToHitMap the mapping between Pandora and ART hits
     *  @param  pCaloHit the input Pandora hit (2D)
     */
    static art::Ptr<recob::Hit> GetHit(const IdToHitMap& idToHitMap,
                                       const pandora::CaloHit* const pCaloHit);

    /**
     *  @brief  Convert pandora vertices to ART vertices and add them to the output vector
     *
     *  @param  vertexVector the input list of pandora vertices
     *  @param  outputVertices the output vector of ART vertices
     */
    static void BuildVertices(const pandora::VertexVector& vertexVector,
                              VertexCollection& outputVertices);

    /**
     *  @brief  Convert pandora 3D hits to ART spacepoints and add them to the output vector
     *          Create the associations between spacepoints and hits
     *
     *  @param  event the art event
     *  @param  threeDHitList the input list of 3D hits to convert
     *  @param  pandoraHitToArtHitMap the input mapping from pandora hits to ART hits
     *  @param  outputSpacePoints the output vector of spacepoints
     *  @param  outputSpacePointsToHits the output associations between spacepoints and hits
     */
    static void BuildSpacePoints(const art::Event& event,
                                 const std::string& instanceLabel,
                                 const pandora::CaloHitList& threeDHitList,
                                 const CaloHitToArtHitMap& pandoraHitToArtHitMap,
                                 SpacePointCollection& outputSpacePoints,
                                 SpacePointToHitCollection& outputSpacePointsToHits);

    /**
     *  @brief  Convert pandora 2D clusters to ART clusters and add them to the output vector
     *          Create the associations between clusters and hits.
     *          For multiple drift volumes, each pandora cluster can correspond to multiple ART clusters.
     *
     *  @param  event the art event
     *  @param  clusterList the input list of 2D pandora clusters to convert
     *  @param  pandoraHitToArtHitMap the input mapping from pandora hits to ART hits
     *  @param  pfoToClustersMap the input mapping from pfo ID to cluster IDs
     *  @param  outputClusters the output vector of clusters
     *  @param  outputClustersToHits the output associations between clusters and hits
     *  @param  pfoToArtClustersMap the output mapping from pfo ID to art cluster ID
     */
    static void BuildClusters(const art::Event& event,
                              const std::string& instanceLabel,
                              const pandora::ClusterList& clusterList,
                              const CaloHitToArtHitMap& pandoraHitToArtHitMap,
                              const IdToIdVectorMap& pfoToClustersMap,
                              ClusterCollection& outputClusters,
                              ClusterToHitCollection& outputClustersToHits,
                              IdToIdVectorMap& pfoToArtClustersMap);

    /**
     *  @brief  Convert between pfos and PFParticles and add them to the output vector
     *          Create the associations between PFParticle and vertices, spacepoints and clusters
     *
     *  @param  event the art event
     *  @param  pfoVector the input list of pfos to convert
     *  @param  pfoToVerticesMap the input mapping from pfo ID to vertex IDs
     *  @param  pfoToThreeDHitsMap the input mapping from pfo ID to 3D hit IDs
     *  @param  pfoToArtClustersMap the input mapping from pfo ID to ART cluster IDs
     *  @param  outputParticle the output vector of PFParticles
     *  @param  outputParticlesToVertices the output associations between PFParticles and vertices
     *  @param  outputParticlesToSpacePoints the output associations between PFParticles and spacepoints
     *  @param  outputParticlesToClusters the output associations between PFParticles and clusters
     */
    static void BuildPFParticles(const art::Event& event,
                                 const std::string& instanceLabel,
                                 const pandora::PfoVector& pfoVector,
                                 const IdToIdVectorMap& pfoToVerticesMap,
                                 const IdToIdVectorMap& pfoToThreeDHitsMap,
                                 const IdToIdVectorMap& pfoToArtClustersMap,
                                 PFParticleCollection& outputParticles,
                                 PFParticleToVertexCollection& outputParticlesToVertices,
                                 PFParticleToSpacePointCollection& outputParticlesToSpacePoints,
                                 PFParticleToClusterCollection& outputParticlesToClusters);

    /**
     *  @brief  Convert Create the associations between pre-existing PFParticle and additional vertices
     *
     *  @param  event the art event
     *  @param  instanceLabel instance label
     *  @param  pfoVector the input list of pfos to convert
     *  @param  pfoToVerticesMap the input mapping from pfo ID to vertex IDs
     *  @param  outputParticlesToVertices the output associations between PFParticles and vertices
     */
    static void AssociateAdditionalVertices(
      const art::Event& event,
      const std::string& instanceLabel,
      const pandora::PfoVector& pfoVector,
      const IdToIdVectorMap& pfoToVerticesMap,
      PFParticleToVertexCollection& outputParticlesToVertices);

    /**
     *  @brief  Build metadata objects from a list of input pfos
     *
     *  @param  event the art event
     *  @param  pfoVector the input list of pfos
     *  @param  outputParticleMetadata the output vector of PFParticleMetadata
     *  @param  outputParticlesToMetadata the output associations between PFParticles and metadata
     */
    static void BuildParticleMetadata(const art::Event& event,
                                      const std::string& instanceLabel,
                                      const pandora::PfoVector& pfoVector,
                                      PFParticleMetadataCollection& outputParticleMetadata,
                                      PFParticleToMetadataCollection& outputParticlesToMetadata);

    /**
     *  @brief  Build slices - collections of hits which each describe a single particle hierarchy
     *
     *  @param  settings the settings
     *  @param  pPrimaryPandora the primary pandora instance
     *  @param  event the art event
     *  @param  instanceLabel the label for the collections to be produced
     *  @param  pfoVector the input vector of all pfos to be output
     *  @param  idToHitMap input mapping from pandora hit ID to ART hit
     *  @param  outputSlices the output collection of slices to populate
     *  @param  outputParticlesToSlices the output association from particles to slices
     *  @param  outputSlicesToHits the output association from slices to hits
     */
    static void BuildSlices(const Settings& settings,
                            const pandora::Pandora* const pPrimaryPandora,
                            const art::Event& event,
                            const std::string& instanceLabel,
                            const pandora::PfoVector& pfoVector,
                            const IdToHitMap& idToHitMap,
                            SliceCollection& outputSlices,
                            PFParticleToSliceCollection& outputParticlesToSlices,
                            SliceToHitCollection& outputSlicesToHits);

    /**
     *  @brief  Build a new slice object with dummy information
     *
     *  @param  outputSlices the output collection of slices to populate
     */
    static unsigned int BuildDummySlice(SliceCollection& outputSlices);

    /**
     *  @brief  Ouput a single slice containing all of the input hits
     *
     *  @param  settings the settings
     *  @param  event the art event
     *  @param  instanceLabel the label for the collections to be produced
     *  @param  pfoVector the input vector of all pfos to be output
     *  @param  idToHitMap input mapping from pandora hit ID to ART hit
     *  @param  outputSlices the output collection of slices to populate
     *  @param  outputParticlesToSlices the output association from particles to slices
     *  @param  outputSlicesToHits the output association from slices to hits
     */
    static void CopyAllHitsToSingleSlice(const Settings& settings,
                                         const art::Event& event,
                                         const std::string& instanceLabel,
                                         const pandora::PfoVector& pfoVector,
                                         const IdToHitMap& idToHitMap,
                                         SliceCollection& outputSlices,
                                         PFParticleToSliceCollection& outputParticlesToSlices,
                                         SliceToHitCollection& outputSlicesToHits);

    /**
     *  @brief  Build a new slice object from a PFO, this can be a top-level parent in a hierarchy or a "slice PFO" from the slicing instance
     *
     *  @param  pParentPfo the parent pfo from which to build the slice
     *  @param  event the art event
     *  @param  instanceLabel the label for the collections to be produced
     *  @param  idToHitMap input mapping from pandora hit ID to ART hit
     *  @param  outputSlices the output collection of slices to populate
     *  @param  outputSlicesToHits the output association from slices to hits
     */
    static unsigned int BuildSlice(const pandora::ParticleFlowObject* const pParentPfo,
                                   const art::Event& event,
                                   const std::string& instanceLabel,
                                   const IdToHitMap& idToHitMap,
                                   SliceCollection& outputSlices,
                                   SliceToHitCollection& outputSlicesToHits);

    /**
     *  @brief  Calculate the T0 of each pfos and add them to the output vector
     *          Create the associations between PFParticle and T0s
     *
     *  @param  event the art event
     *  @param  instanceLabel the label for the collections to be produced
     *  @param  pfoVector the input list of pfos
     *  @param  outputT0s the output vector of T0s
     *  @param  outputParticlesToT0s the output associations between PFParticles and T0s
     */
    static void BuildT0s(const art::Event& event,
                         const std::string& instanceLabel,
                         const pandora::PfoVector& pfoVector,
                         T0Collection& outputT0s,
                         PFParticleToT0Collection& outputParticlesToT0s);

    /**
     *  @brief  Convert from a pandora vertex to an ART vertex
     *
     *  @param  pVertex the input vertex
     *  @param  vertexId the id of the vertex to produce
     *
     *  @param  the ART vertex
     */
    static recob::Vertex BuildVertex(const pandora::Vertex* const pVertex, const size_t vertexId);

    /**
     *  @brief  Convert from a pandora 3D hit to an ART spacepoint
     *
     *  @param  pCaloHit the input hit
     *  @param  spacePointId the id of the space-point to produce
     *
     *  @param  the ART spacepoint
     */
    static recob::SpacePoint BuildSpacePoint(const pandora::CaloHit* const pCaloHit,
                                             const size_t spacePointId);

    /**
     *  @brief  Collect a sorted list of all 2D hits in a cluster
     *
     *  @param  pCluster the input cluster
     *  @param  sortedHits the output vector of sorted 2D hits
     */
    static void GetHitsInCluster(const pandora::Cluster* const pCluster,
                                 pandora::CaloHitVector& sortedHits);

    /**
     *  @brief  Convert from a pandora 2D cluster to a vector of ART clusters (produce multiple if the cluster is split over drift volumes)
     *
     *  @param  pCluster the input cluster
     *  @param  clusterList the input list of clusters
     *  @param  pandoraHitToArtHitMap the input mapping from pandora hits to ART hits
     *  @param  pandoraClusterToArtClustersMap output mapping from pandora cluster ID to art cluster IDs
     *  @param  hitVectors the output vectors of hits for each cluster produced used to produce associations
     *  @param  algo algorithm set to fill cluster members
     *
     *  @param  the vector of ART clusters
     */
    static std::vector<recob::Cluster> BuildClusters(
      util::GeometryUtilities const& gser,
      const pandora::Cluster* const pCluster,
      const pandora::ClusterList& clusterList,
      const CaloHitToArtHitMap& pandoraHitToArtHitMap,
      IdToIdVectorMap& pandoraClusterToArtClustersMap,
      std::vector<HitVector>& hitVectors,
      size_t& nextId,
      cluster::ClusterParamsAlgBase& algo);

    /**
     *  @brief  Build an ART cluster from an input vector of ART hits
     *
     *  @param  id the id code for the cluster
     *  @param  hitVector the input vector of hits
     *  @param  isolatedHits the input list of isolated hits
     *  @param  algo algorithm set to fill cluster members
     *
     *  @return the ART cluster
     *
     *  If you don't know which algorithm to pick, StandardClusterParamsAlg is a good default.
     *  The hits that are isolated (that is, present in isolatedHits) are not fed to the cluster parameter algorithms.
     */
    static recob::Cluster BuildCluster(util::GeometryUtilities const& gser,
                                       const size_t id,
                                       const HitVector& hitVector,
                                       const HitList& isolatedHits,
                                       cluster::ClusterParamsAlgBase& algo);

    /**
     *  @brief  Convert from a pfo to and ART PFParticle
     *
     *  @param  pPfo the input pfo to convert
     *  @param  pfoId the id of the pfo to produce
     *  @param  pfoVector the input list of pfos
     *
     *  @param  the ART PFParticle
     */
    static recob::PFParticle BuildPFParticle(const pandora::ParticleFlowObject* const pPfo,
                                             const size_t pfoId,
                                             const pandora::PfoVector& pfoVector);

    /**
     *  @brief  If required, build a T0 for the input pfo
     *
     *  @param  event the ART event
     *  @param  pPfo the input pfo
     *  @param  pfoVector the input list of pfos
     *  @param  nextId the ID of the T0 - will be incremented if the t0 was produced
     *  @param  t0 the output T0
     *
     *  @return if a T0 was produced (calculated from the stitching hit shift distance)
     */
    static bool BuildT0(const art::Event& event,
                        const pandora::ParticleFlowObject* const pPfo,
                        const pandora::PfoVector& pfoVector,
                        size_t& nextId,
                        anab::T0& t0);

    /**
     *  @brief  Add an association between objects with two given ids
     *
     *  @param  event the ART event
     *  @param  idA the id of an object of type A
     *  @param  idB the id of an object of type B to associate to the first object
     *  @param  association the output association to update
     */
    template <typename A, typename B>
    static void AddAssociation(const art::Event& event,
                               const std::string& instanceLabel,
                               const size_t idA,
                               const size_t idB,
                               std::unique_ptr<art::Assns<A, B>>& association);

    /**
     *  @brief  Add associations between input objects
     *
     *  @param  event the ART event
     *  @param  idA the id of an object of type A
     *  @param  aToBMap the input mapping from IDs of objects of type A to IDs of objects of type B to associate
     *  @param  association the output association to update
     */
    template <typename A, typename B>
    static void AddAssociation(const art::Event& event,
                               const std::string& instanceLabel,
                               const size_t idA,
                               const IdToIdVectorMap& aToBMap,
                               std::unique_ptr<art::Assns<A, B>>& association);

    /**
     *  @brief  Add associations between input objects
     *
     *  @param  event the ART event
     *  @param  idA the id of an object of type A
     *  @param  bVector the input vector of IDs of objects of type B to associate
     *  @param  association the output association to update
     */
    template <typename A, typename B>
    static void AddAssociation(const art::Event& event,
                               const std::string& instanceLabel,
                               const size_t idA,
                               const std::vector<art::Ptr<B>>& bVector,
                               std::unique_ptr<art::Assns<A, B>>& association);
  };

  //------------------------------------------------------------------------------------------------------------------------------------------

  template <typename T>
  inline size_t
  LArPandoraOutput::GetId(const T* const pT, const std::list<const T*>& tList)
  {
    typename std::list<const T*>::const_iterator it(std::find(tList.begin(), tList.end(), pT));

    if (it == tList.end())
      throw cet::exception("LArPandora")
        << " LArPandoraOutput::GetId --- can't find the id of supplied object";

    return static_cast<size_t>(std::distance(tList.begin(), it));
  }

  //------------------------------------------------------------------------------------------------------------------------------------------

  template <typename T>
  inline size_t
  LArPandoraOutput::GetId(const T* const pT, const std::vector<const T*>& tVector)
  {
    typename std::vector<const T*>::const_iterator it(
      std::find(tVector.begin(), tVector.end(), pT));

    if (it == tVector.end())
      throw cet::exception("LArPandora")
        << " LArPandoraOutput::GetId --- can't find the id of supplied object";

    return static_cast<size_t>(std::distance(tVector.begin(), it));
  }

  //------------------------------------------------------------------------------------------------------------------------------------------

  template <typename A, typename B>
  inline void
  LArPandoraOutput::AddAssociation(const art::Event& event,
                                   const std::string& instanceLabel,
                                   const size_t idA,
                                   const size_t idB,
                                   std::unique_ptr<art::Assns<A, B>>& association)
  {
    const art::PtrMaker<A> makePtrA(event, instanceLabel);
    art::Ptr<A> pA(makePtrA(idA));

    const art::PtrMaker<B> makePtrB(event, instanceLabel);
    art::Ptr<B> pB(makePtrB(idB));

    association->addSingle(pA, pB);
  }

  //------------------------------------------------------------------------------------------------------------------------------------------

  template <typename A, typename B>
  inline void
  LArPandoraOutput::AddAssociation(const art::Event& event,
                                   const std::string& instanceLabel,
                                   const size_t idA,
                                   const IdToIdVectorMap& aToBMap,
                                   std::unique_ptr<art::Assns<A, B>>& association)
  {
    IdToIdVectorMap::const_iterator it(aToBMap.find(idA));
    if (it == aToBMap.end())
      throw cet::exception("LArPandora")
        << " LArPandoraOutput::AddAssociation --- id doesn't exists in the assocaition map";

    const art::PtrMaker<A> makePtrA(event, instanceLabel);
    art::Ptr<A> pA(makePtrA(idA));

    const art::PtrMaker<B> makePtrB(event, instanceLabel);
    for (const size_t idB : it->second) {
      art::Ptr<B> pB(makePtrB(idB));
      association->addSingle(pA, pB);
    }
  }

  //------------------------------------------------------------------------------------------------------------------------------------------

  template <typename A, typename B>
  inline void
  LArPandoraOutput::AddAssociation(const art::Event& event,
                                   const std::string& instanceLabel,
                                   const size_t idA,
                                   const std::vector<art::Ptr<B>>& bVector,
                                   std::unique_ptr<art::Assns<A, B>>& association)
  {
    const art::PtrMaker<A> makePtrA(event, instanceLabel);
    art::Ptr<A> pA(makePtrA(idA));

    for (const art::Ptr<B>& pB : bVector)
      association->addSingle(pA, pB);
  }

} // namespace lar_pandora

#endif //  LAR_PANDORA_OUTPUT_H