#ifndef HEPHISTCOMBINER_H
#define HEPHISTCOMBINER_H


// ----------------------------------------------------------------------
//
// HepHistCombiner.cc - definition of class HepHistCombiner
//
// Intended to give the user access to the histogram (1D, 2D and Prof)
// objects being combined by HepFileManager::combine. The strategy is that
// this is implemented as a base class with nearly do-nothing, virtual
// member functions.  The user should write a descendent class which
// overrides these member functions with whatever form of combination
// may be appropriate for his/her application.  The test that the two
// histograms are compatible is implemented in the base class functions
// and may be called explicitely by the user. It is *not* called implicitely
// if these functions are overridden. Note that incompatible histogram
// objects ZMthrow warning level (i. e., non-fatal) ZMexceptions.
//
//    1-Mar-2001  J. Marraffino   Initial definition
//
// ----------------------------------------------------------------------


#ifndef ZMENVIRONMENT_H
  #include "ZMutility/ZMenvironment.h"
#endif

#ifndef HEPHIST1D_H
#include "HepTuple/HepHist1D.h"
#endif

#ifndef HEPHIST2D_H
#include "HepTuple/HepHist2D.h"
#endif

#ifndef HEPHISTPROF_H
#include "HepTuple/HepHistProf.h"
#endif


ZM_BEGIN_NAMESPACE( zmht )	/*  namespace zmht  {  */

class HepHistCombiner  {

public:

  virtual void combine( HepHist1D & targetHist,   const HepHist1D & sourceHist );

  virtual void combine( HepHist2D & targetHist,   const HepHist2D & sourceHist );

  virtual void combine( HepHistProf & targetHist, const HepHistProf & sourceHist );

};  // HepHistCombiner

ZM_END_NAMESPACE( zmht )	/*  }  // namespace zmht  */

#endif  // HEPHISTCOMBINER_H