// @(#)root/tree:$Id: TTree.h 28831 2009-06-05 11:45:41Z pcanal $
// Author: Rene Brun   12/01/96

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TTree
#define ROOT_TTree

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TTree                                                                //
//                                                                      //
// A TTree object is a list of TBranch.                                 //
//   To Create a TTree object one must:                                 //
//    - Create the TTree header via the TTree constructor               //
//    - Call the TBranch constructor for every branch.                  //
//                                                                      //
//   To Fill this object, use member function Fill with no parameters.  //
//     The Fill function loops on all defined TBranch.                  //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#ifndef ROOT_TBranch
#include "TBranch.h"
#endif

#ifndef ROOT_TObjArray
#include "TObjArray.h"
#endif

#ifndef ROOT_TAttLine
#include "TAttLine.h"
#endif

#ifndef ROOT_TAttFill
#include "TAttFill.h"
#endif

#ifndef ROOT_TAttMarker
#include "TAttMarker.h"
#endif

#ifndef ROOT_TArrayD
#include "TArrayD.h"
#endif

#ifndef ROOT_TArrayI
#include "TArrayI.h"
#endif

#ifndef ROOT_TDataType
#include "TDataType.h"
#endif

#ifndef ROOT_TClass
#include "TClass.h"
#endif

#ifndef ROOT_TVirtualTreePlayer
#include "TVirtualTreePlayer.h"
#endif

class TBranch;
class TBrowser;
class TFile;
class TDirectory;
class TLeaf;
class TH1;
class TTreeFormula;
class TPolyMarker;
class TEventList;
class TEntryList;
class TList;
class TSQLResult;
class TSelector;
class TPrincipal;
class TFriendElement;
class TCut;
class TVirtualIndex;
class TBranchRef;
class TBasket;
class TStreamerInfo;

class TTree : public TNamed, public TAttLine, public TAttFill, public TAttMarker {

protected:
   Long64_t       fEntries;           //  Number of entries
   Long64_t       fTotBytes;          //  Total number of bytes in all branches before compression
   Long64_t       fZipBytes;          //  Total number of bytes in all branches after compression
   Long64_t       fSavedBytes;        //  Number of autosaved bytes
   Double_t       fWeight;            //  Tree weight (see TTree::SetWeight)
   Int_t          fTimerInterval;     //  Timer interval in milliseconds
   Int_t          fScanField;         //  Number of runs before prompting in Scan
   Int_t          fUpdate;            //  Update frequency for EntryLoop
   Long64_t       fMaxEntries;        //  Maximum number of entries in case of circular buffers
   Long64_t       fMaxEntryLoop;      //  Maximum number of entries to process
   Long64_t       fMaxVirtualSize;    //  Maximum total size of buffers kept in memory
   Long64_t       fAutoSave;          //  Autosave tree when fAutoSave bytes produced
   Long64_t       fEstimate;          //  Number of entries to estimate histogram limits
   Long64_t       fCacheSize;         //! Maximum size of file buffers
   Long64_t       fChainOffset;       //! Offset of 1st entry of this Tree in a TChain
   Long64_t       fReadEntry;         //! Number of the entry being processed
   Long64_t       fTotalBuffers;      //! Total number of bytes in branch buffers
   Int_t          fPacketSize;        //! Number of entries in one packet for parallel root
   Int_t          fNfill;             //! Local for EntryLoop
   Int_t          fDebug;             //! Debug level
   Long64_t       fDebugMin;          //! First entry number to debug
   Long64_t       fDebugMax;          //! Last entry number to debug
   Int_t          fMakeClass;         //! not zero when processing code generated by MakeClass
   Int_t          fFileNumber;        //! current file number (if file extensions)
   TObject       *fNotify;            //! Object to be notified when loading a Tree
   TDirectory    *fDirectory;         //! Pointer to directory holding this tree
   TObjArray      fBranches;          //  List of Branches
   TObjArray      fLeaves;            //  Direct pointers to individual branch leaves
   TList         *fAliases;           //  List of aliases for expressions based on the tree branches.
   TEventList    *fEventList;         //! Pointer to event selection list (if one)
   TEntryList    *fEntryList;         //! Pointer to event selection list (if one)
   TArrayD        fIndexValues;       //  Sorted index values
   TArrayI        fIndex;             //  Index of sorted values
   TVirtualIndex *fTreeIndex;         //  Pointer to the tree Index (if any)
   TList         *fFriends;           //  pointer to list of friend elements
   TList         *fUserInfo;          //  pointer to a list of user objects associated to this Tree
   TVirtualTreePlayer *fPlayer;       //! Pointer to current Tree player
   TList         *fClones;            //! List of cloned trees which share our addresses
   TBranchRef    *fBranchRef;         //  Branch supporting the TRefTable (if any)
   UInt_t         fFriendLockStatus;  //! Record which method is locking the friend recursion

   static Int_t     fgBranchStyle;      //  Old/New branch style
   static Long64_t  fgMaxTreeSize;      //  Maximum size of a file containg a Tree

private:
   TTree(const TTree& tt);              // not implemented
   TTree& operator=(const TTree& tt);   // not implemented

protected:
   void             AddClone(TTree*);
   const   char    *GetNameByIndex(TString& varexp, Int_t* index, Int_t colindex) const;
   virtual void     KeepCircular();
   virtual void     MakeIndex(TString& varexp, Int_t* index);
   virtual TBranch *BranchImp(const char* branchname, const char* classname, TClass* ptrClass, void* addobj, Int_t bufsize, Int_t splitlevel);
   virtual TBranch *BranchImp(const char* branchname, TClass* ptrClass, void* addobj, Int_t bufsize, Int_t splitlevel);
   virtual TBranch *BranchImpRef(const char* branchname, TClass* ptrClass, EDataType datatype, void* addobj, Int_t bufsize, Int_t splitlevel);
   virtual Bool_t   CheckBranchAddressType(TBranch* branch, TClass* ptrClass, EDataType datatype, Bool_t ptr);
   virtual TBranch *BronchExec(const char* name, const char* classname, void* addobj, Bool_t isptrptr, Int_t bufsize, Int_t splitlevel);
   friend TBranch *TTreeBranchImpRef(TTree *tree, const char* branchname, TClass* ptrClass, EDataType datatype, void* addobj, Int_t bufsize, Int_t splitlevel);

   class TFriendLock {
      // Helper class to prevent infinite recursion in the
      // usage of TTree Friends. Implemented in TTree.cxx.
      TTree  *fTree;      // Pointer to the locked tree
      UInt_t  fMethodBit; // BIT for the locked method
      Bool_t  fPrevious;  // Previous value of the BIT.

   protected:
      TFriendLock(const TFriendLock&);
      TFriendLock& operator=(const TFriendLock&);

   public:
      TFriendLock(TTree* tree, UInt_t methodbit);
      ~TFriendLock();
   };
   friend class TFriendLock;

   // use to update fFriendLockStatus
   enum ELockStatusBits {
      kFindBranch        = BIT(0),
      kFindLeaf          = BIT(1),
      kGetAlias          = BIT(2),
      kGetBranch         = BIT(3),
      kGetEntry          = BIT(4),
      kGetEntryWithIndex = BIT(5),
      kGetFriend         = BIT(6),
      kGetFriendAlias    = BIT(7),
      kGetLeaf           = BIT(8),
      kLoadTree          = BIT(9),
      kPrint             = BIT(10),
      kRemoveFriend      = BIT(12),
      kSetBranchStatus   = BIT(12)
   };

public:
   // TTree status bits
   enum {
      kForceRead   = BIT(11),
      kCircular    = BIT(12)
   };

   TTree();
   TTree(const char* name, const char* title, Int_t splitlevel = 99);
   virtual ~TTree();

   virtual TFriendElement *AddFriend(const char* treename, const char* filename = "");
   virtual TFriendElement *AddFriend(const char* treename, TFile* file);
   virtual TFriendElement *AddFriend(TTree* tree, const char* alias = "", Bool_t warn = kFALSE);
   virtual void            AddTotBytes(Int_t tot) { fTotBytes += tot; }
   virtual void            AddZipBytes(Int_t zip) { fZipBytes += zip; }
   virtual Long64_t        AutoSave(Option_t* option = "");
   virtual Int_t           Branch(TCollection* list, Int_t bufsize = 32000, Int_t splitlevel = 99, const char* name = "");
   virtual Int_t           Branch(TList* list, Int_t bufsize = 32000, Int_t splitlevel = 99);
   virtual Int_t           Branch(const char* folder, Int_t bufsize = 32000, Int_t splitlevel = 99);
   virtual TBranch        *Branch(const char* name, void* address, const char* leaflist, Int_t bufsize = 32000);
#if !defined(__CINT__)
   virtual TBranch        *Branch(const char* name, const char* classname, void* addobj, Int_t bufsize = 32000, Int_t splitlevel = 99);
#endif
   template <class T> TBranch *Branch(const char* name, const char* classname, T** addobj, Int_t bufsize = 32000, Int_t splitlevel = 99)
   {
      // See BranchImp for details
      return BranchImp(name, classname, TBuffer::GetClass(typeid(T)), addobj, bufsize, splitlevel);
   }
   template <class T> TBranch *Branch(const char* name, T** addobj, Int_t bufsize = 32000, Int_t splitlevel = 99)
   {
      // See BranchImp for details
      return BranchImp(name, TBuffer::GetClass(typeid(T)), addobj, bufsize, splitlevel);
   }
   template <class T> TBranch *Branch(const char* name, T* obj, Int_t bufsize = 32000, Int_t splitlevel = 99)
   {
      // See BranchImp for details
      return BranchImpRef(name, TBuffer::GetClass(typeid(T)), TDataType::GetType(typeid(T)), obj, bufsize, splitlevel);
   }
   virtual TBranch        *Bronch(const char* name, const char* classname, void* addobj, Int_t bufsize = 32000, Int_t splitlevel = 99);
   virtual TBranch        *BranchOld(const char* name, const char* classname, void* addobj, Int_t bufsize = 32000, Int_t splitlevel = 1);
   virtual TBranch        *BranchRef();
   virtual void            Browse(TBrowser*);
   virtual Int_t           BuildIndex(const char* majorname, const char* minorname = "0");
   TStreamerInfo          *BuildStreamerInfo(TClass* cl, void* pointer = 0);
   virtual TFile          *ChangeFile(TFile* file);
   virtual TTree          *CloneTree(Long64_t nentries = -1, Option_t* option = "");
   virtual void            CopyAddresses(TTree*,Bool_t undo = kFALSE);
   virtual Long64_t        CopyEntries(TTree* tree, Long64_t nentries = -1);
   virtual TTree          *CopyTree(const char* selection, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   virtual TBasket        *CreateBasket(TBranch*);
   virtual void            DirectoryAutoAdd(TDirectory *);
   Int_t                   Debug() const { return fDebug; }
   virtual void            Delete(Option_t* option = ""); // *MENU*
   virtual void            Draw(Option_t* opt) { Draw(opt, "", "", 1000000000, 0); }
   virtual Long64_t        Draw(const char* varexp, const TCut& selection, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   virtual Long64_t        Draw(const char* varexp, const char* selection, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0); // *MENU*
   virtual void            DropBaskets();
   virtual void            DropBuffers(Int_t nbytes);
   virtual Int_t           Fill();
   virtual TBranch        *FindBranch(const char* name);
   virtual TLeaf          *FindLeaf(const char* name);
   virtual Int_t           Fit(const char* funcname, const char* varexp, const char* selection = "", Option_t* option = "", Option_t* goption = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0); // *MENU*
   virtual Int_t           FlushBaskets() const;
   virtual const char     *GetAlias(const char* aliasName) const;
   virtual TBranch        *GetBranch(const char* name);
   virtual TBranchRef     *GetBranchRef() const { return fBranchRef; };
   virtual Bool_t          GetBranchStatus(const char* branchname) const;
   static  Int_t           GetBranchStyle();
   virtual Long64_t        GetCacheSize() const { return fCacheSize; }
   virtual Long64_t        GetChainEntryNumber(Long64_t entry) const { return entry; }
   virtual Long64_t        GetChainOffset() const { return fChainOffset; }
   TFile                  *GetCurrentFile() const;
           Long64_t        GetDebugMax()  const { return fDebugMax; }
           Long64_t        GetDebugMin()  const { return fDebugMin; }
   TDirectory             *GetDirectory() const { return fDirectory; }
   virtual Long64_t        GetEntries() const   { return fEntries; }
   virtual Long64_t        GetEntries(const char *selection);
   virtual Long64_t        GetEntriesFast() const   { return fEntries; }
   virtual Long64_t        GetEntriesFriend() const;
   virtual Long64_t        GetEstimate() const { return fEstimate; }
   virtual Int_t           GetEntry(Long64_t entry = 0, Int_t getall = 0);
           Int_t           GetEvent(Long64_t entry = 0, Int_t getall = 0) { return GetEntry(entry, getall); }
   virtual Int_t           GetEntryWithIndex(Int_t major, Int_t minor = 0);
   virtual Long64_t        GetEntryNumberWithBestIndex(Int_t major, Int_t minor = 0) const;
   virtual Long64_t        GetEntryNumberWithIndex(Int_t major, Int_t minor = 0) const;
   TEventList             *GetEventList() const { return fEventList; }
   virtual TEntryList     *GetEntryList();
   virtual Long64_t        GetEntryNumber(Long64_t entry) const;
   virtual Int_t           GetFileNumber() const { return fFileNumber; }
   virtual TTree          *GetFriend(const char*) const;
   virtual const char     *GetFriendAlias(TTree*) const;
   TH1                    *GetHistogram() { return GetPlayer()->GetHistogram(); }
   virtual Int_t          *GetIndex() { return &fIndex.fArray[0]; }
   virtual Double_t       *GetIndexValues() { return &fIndexValues.fArray[0]; }
   virtual TIterator      *GetIteratorOnAllLeaves(Bool_t dir = kIterForward);
   virtual TLeaf          *GetLeaf(const char* name);
   virtual TList          *GetListOfClones() { return fClones; }
   virtual TObjArray      *GetListOfBranches() { return &fBranches; }
   virtual TObjArray      *GetListOfLeaves() { return &fLeaves; }
   virtual TList          *GetListOfFriends() const { return fFriends; }
   virtual TList          *GetListOfAliases() const { return fAliases; }

   // GetMakeClass is left non-virtual for efficiency reason.
   // Making it virtual affects the performance of the I/O
           Int_t           GetMakeClass() const { return fMakeClass; }

   virtual Long64_t        GetMaxEntryLoop() const { return fMaxEntryLoop; }
   virtual Double_t        GetMaximum(const char* columname);
   static  Long64_t        GetMaxTreeSize();
   virtual Long64_t        GetMaxVirtualSize() const { return fMaxVirtualSize; }
   virtual Double_t        GetMinimum(const char* columname);
   virtual Int_t           GetNbranches() { return fBranches.GetEntriesFast(); }
   TObject                *GetNotify() const { return fNotify; }
   TVirtualTreePlayer     *GetPlayer();
   virtual Int_t           GetPacketSize() const { return fPacketSize; }
   virtual Long64_t        GetReadEntry()  const { return fReadEntry; }
   virtual Long64_t        GetReadEvent()  const { return fReadEntry; }
   virtual Int_t           GetScanField()  const { return fScanField; }
   TTreeFormula           *GetSelect()    { return GetPlayer()->GetSelect(); }
   virtual Long64_t        GetSelectedRows() { return GetPlayer()->GetSelectedRows(); }
   virtual Int_t           GetTimerInterval() const { return fTimerInterval; }
   virtual Long64_t        GetTotBytes() const { return fTotBytes; }
   virtual TTree          *GetTree() const { return const_cast<TTree*>(this); }
   virtual TVirtualIndex  *GetTreeIndex() const { return fTreeIndex; }
   virtual Int_t           GetTreeNumber() const { return 0; }
   virtual Int_t           GetUpdate() const { return fUpdate; }
   virtual TList          *GetUserInfo();
   TTreeFormula           *GetVar(Int_t i)  { return GetPlayer()->GetVar(i); }
   TTreeFormula           *GetVar1() { return GetPlayer()->GetVar1(); }
   TTreeFormula           *GetVar2() { return GetPlayer()->GetVar2(); }
   TTreeFormula           *GetVar3() { return GetPlayer()->GetVar3(); }
   TTreeFormula           *GetVar4() { return GetPlayer()->GetVar4(); }
   virtual Double_t       *GetVal(Int_t i)   { return GetPlayer()->GetVal(i); }
   virtual Double_t       *GetV1()   { return GetPlayer()->GetV1(); }
   virtual Double_t       *GetV2()   { return GetPlayer()->GetV2(); }
   virtual Double_t       *GetV3()   { return GetPlayer()->GetV3(); }
   virtual Double_t       *GetV4()   { return GetPlayer()->GetV4(); }
   virtual Double_t       *GetW()    { return GetPlayer()->GetW(); }
   virtual Double_t        GetWeight() const   { return fWeight; }
   virtual Long64_t        GetZipBytes() const { return fZipBytes; }
   virtual void            IncrementTotalBuffers(Int_t nbytes) { fTotalBuffers += nbytes; }
   Bool_t                  IsFolder() const { return kTRUE; }
   virtual Int_t           LoadBaskets(Long64_t maxmemory = 2000000000);
   virtual Long64_t        LoadTree(Long64_t entry);
   virtual Long64_t        LoadTreeFriend(Long64_t entry, TTree* T);
   virtual Int_t           MakeClass(const char* classname = 0, Option_t* option = "");
   virtual Int_t           MakeCode(const char* filename = 0);
   virtual Int_t           MakeProxy(const char* classname, const char* macrofilename = 0, const char* cutfilename = 0, const char* option = 0, Int_t maxUnrolling = 3);
   virtual Int_t           MakeSelector(const char* selector = 0);
   Bool_t                  MemoryFull(Int_t nbytes);
   virtual Long64_t        Merge(TCollection* list, Option_t* option = "");
   static  TTree          *MergeTrees(TList* list, Option_t* option = "");
   virtual Bool_t          Notify();
   TPrincipal             *Principal(const char* varexp = "", const char* selection = "", Option_t* option = "np", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   virtual void            Print(Option_t* option = "") const; // *MENU*
   virtual Long64_t        Process(const char* filename, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0); // *MENU*
#if defined(__CINT__)
#if defined(R__MANUAL_DICT)
   virtual Long64_t        Process(void* selector, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
#endif
#else
   virtual Long64_t        Process(TSelector* selector, Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
#endif
   virtual Long64_t        Project(const char* hname, const char* varexp, const char* selection = "", Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   virtual TSQLResult     *Query(const char* varexp = "", const char* selection = "", Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   virtual Long64_t        ReadFile(const char* filename, const char* branchDescriptor = "");
   virtual void            Refresh();
   virtual void            RecursiveRemove(TObject *obj);
   virtual void            RemoveFriend(TTree*);
   virtual void            Reset(Option_t* option = "");
   virtual void            ResetBranchAddress(TBranch *);
   virtual void            ResetBranchAddresses();
   virtual Long64_t        Scan(const char* varexp = "", const char* selection = "", Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0); // *MENU*
   virtual Bool_t          SetAlias(const char* aliasName, const char* aliasFormula);
   virtual void            SetAutoSave(Long64_t autos = 10000000) { fAutoSave=autos; }
   virtual void            SetBasketSize(const char* bname, Int_t buffsize = 16000);
#if !defined(__CINT__)
   virtual void         SetBranchAddress(const char *bname,void *add, TBranch **ptr = 0);
#endif
   virtual void         SetBranchAddress(const char *bname,void *add, TClass *realClass, EDataType datatype, Bool_t isptr);
   virtual void         SetBranchAddress(const char *bname,void *add, TBranch **ptr, TClass *realClass, EDataType datatype, Bool_t isptr);
   template <class T> void SetBranchAddress(const char *bname, T **add, TBranch **ptr = 0) {
      SetBranchAddress(bname,add,ptr,TClass::GetClass(typeid(T)),TDataType::GetType(typeid(T)),true);
   }
#ifndef R__NO_CLASS_TEMPLATE_SPECIALIZATION
   // This can only be used when the template overload resolution can distringuish between
   // T* and T**
   template <class T> void SetBranchAddress(const char *bname, T *add, TBranch **ptr = 0) {
      SetBranchAddress(bname,add,ptr,TClass::GetClass(typeid(T)),TDataType::GetType(typeid(T)),false);
   }
#endif
   virtual void            SetBranchStatus(const char* bname, Bool_t status = 1, UInt_t* found = 0);
   static  void            SetBranchStyle(Int_t style = 1);  //style=0 for old branch, =1 for new branch style
   virtual void            SetCacheSize(Long64_t cachesize = 10000000);
   virtual void            SetChainOffset(Long64_t offset = 0) { fChainOffset=offset; }
   virtual void            SetCircular(Long64_t maxEntries);
   virtual void            SetDebug(Int_t level = 1, Long64_t min = 0, Long64_t max = 9999999); // *MENU*
   virtual void            SetDirectory(TDirectory* dir);
   virtual Long64_t        SetEntries(Long64_t n = -1);
   virtual void            SetEstimate(Long64_t nentries = 10000);
   virtual void            SetFileNumber(Int_t number = 0);
   virtual void            SetEventList(TEventList* list);
   virtual void            SetEntryList(TEntryList* list, Option_t *opt="");
   virtual void            SetMakeClass(Int_t make) { fMakeClass = make; }
   virtual void            SetMaxEntryLoop(Long64_t maxev = 1000000000) { fMaxEntryLoop = maxev; } // *MENU*
   static  void            SetMaxTreeSize(Long64_t maxsize = 1900000000);
   virtual void            SetMaxVirtualSize(Long64_t size = 0) { fMaxVirtualSize = size; } // *MENU*
   virtual void            SetName(const char* name); // *MENU*
   virtual void            SetNotify(TObject* obj) { fNotify = obj; }
   virtual void            SetObject(const char* name, const char* title);
   virtual void            SetScanField(Int_t n = 50) { fScanField = n; } // *MENU*
   virtual void            SetTimerInterval(Int_t msec = 333) { fTimerInterval=msec; }
   virtual void            SetTreeIndex(TVirtualIndex*index);
   virtual void            SetWeight(Double_t w = 1, Option_t* option = "");
   virtual void            SetUpdate(Int_t freq = 0) { fUpdate = freq; }
   virtual void            Show(Long64_t entry = -1, Int_t lenmax = 20);
   virtual void            StartViewer(); // *MENU*
   virtual Int_t           UnbinnedFit(const char* funcname, const char* varexp, const char* selection = "", Option_t* option = "", Long64_t nentries = 1000000000, Long64_t firstentry = 0);
   void                    UseCurrentStyle();
   virtual Int_t           Write(const char *name=0, Int_t option=0, Int_t bufsize=0);
   virtual Int_t           Write(const char *name=0, Int_t option=0, Int_t bufsize=0) const;

   ClassDef(TTree,16)  //Tree descriptor (the main ROOT I/O class)
};

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TTreeFriendLeafIter                                                  //
//                                                                      //
// Iterator on all the leaves in a TTree and its friend                 //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

class TTreeFriendLeafIter : public TIterator {

protected:
   TTree             *fTree;         //tree being iterated
   TIterator         *fLeafIter;     //current leaf sub-iterator.
   TIterator         *fTreeIter;     //current tree sub-iterator.
   Bool_t             fDirection;    //iteration direction

   TTreeFriendLeafIter() : fTree(0), fLeafIter(0), fTreeIter(0),
       fDirection(0) { }

public:
   TTreeFriendLeafIter(const TTree* t, Bool_t dir = kIterForward);
   TTreeFriendLeafIter(const TTreeFriendLeafIter &iter);
   ~TTreeFriendLeafIter() { SafeDelete(fLeafIter); SafeDelete(fTreeIter); }
   TIterator &operator=(const TIterator &rhs);
   TTreeFriendLeafIter &operator=(const TTreeFriendLeafIter &rhs);

   const TCollection *GetCollection() const { return 0; }
   Option_t          *GetOption() const;
   TObject           *Next();
   void               Reset() { SafeDelete(fLeafIter); SafeDelete(fTreeIter); }
   bool operator !=(const TIterator&) const {
      // TODO: Implement me
      return false;
   }
   bool operator !=(const TTreeFriendLeafIter&) const {
      // TODO: Implement me
      return false;
   }
   TObject *operator*() const {
      // TODO: Implement me
      return nullptr;
   }
   ClassDef(TTreeFriendLeafIter,0)  //Linked list iterator
 };


#endif