/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/AthLinks/AthLinks/DataLink.h

// Dear emacs, this is -*- c++ -*-
// $Id: DataLink.h 649074 2015-02-23 16:51:40Z krasznaa $
#ifndef ATHLINKS_DATALINK_H
#define ATHLINKS_DATALINK_H

// System include(s):
extern "C" {
#   include <stdint.h>
}
#include <string>

// Local include(s):
#include "AthLinks/DataLinkBase.h"
#include "AthLinks/tools/selection_ns.h"

// Forward declaration(s):
namespace xAOD {
   class TVirtualEvent;
}
ENTER_ROOT_SELECTION_NS
template< class STORABLE >
class DataLink;
EXIT_ROOT_SELECTION_NS

template< typename STORABLE >
class DataLink : public DataLinkBase {

public:

   typedef std::string ID_type;
   typedef uint32_t sgkey_t;

   typedef STORABLE value_type;
   typedef STORABLE* __attribute__((deprecated)) pointer;
   typedef const STORABLE* const_pointer;
   typedef STORABLE& __attribute__((deprecated)) reference;
   typedef const STORABLE& const_reference;



   DataLink();

   DataLink( xAOD::TVirtualEvent* event );

   DataLink( const_reference data, xAOD::TVirtualEvent* event = 0 );

   DataLink( const_pointer data, xAOD::TVirtualEvent* event = 0 );

   DataLink( const ID_type& id, xAOD::TVirtualEvent* event = 0 );

   DataLink( sgkey_t key, xAOD::TVirtualEvent* event = 0 );

   template< typename T >
   DataLink( const DataLink< T >& parent );



   void toStorableObject( const_reference data );

   void toDefaultObject();

   void toIdentifiedObject( const ID_type& id );
   void toIdentifiedObject( sgkey_t key );



   const_reference operator*() const;
   const_pointer operator->() const { return cptr(); }

   operator const_pointer() const { return cptr(); }

   const_pointer cptr() const;

   bool isValid() const;

   operator bool() const { return isValid(); }
   bool operator!() const { return !isValid(); }

   const ID_type& dataID() const;
   sgkey_t key() const { return persKey(); }


   xAOD::TVirtualEvent* source() const { return m_event; }

   bool toPersistent();

private:
   virtual bool toTransient();
   void findIdentifier();

   mutable const_pointer m_object;
   xAOD::TVirtualEvent* m_event;

   typedef typename ROOT_SELECTION_NS::DataLink< STORABLE >::self DictSel;

}; // class DataLink

/*
 * The following piece of code declares the member variables of all
 * DataLink<T> types as transient.
 */
ENTER_ROOT_SELECTION_NS
template< class STORABLE >
class DataLink
#if ROOT_VERSION_CODE >= ROOT_VERSION( 6, 0, 2 )
   : public SelectNoInstance
#endif // ROOT_VERSION
{

public:
   typedef DataLink< STORABLE > self;

#if ROOT_VERSION_CODE < ROOT_VERSION( 5, 99, 0 )

   ROOT_SELECTION_NS::NO_SELF_AUTOSELECT dummy;

   ROOT_SELECTION_NS::TRANSIENT m_object;
   ROOT_SELECTION_NS::TRANSIENT m_event;

#else

   ROOT_SELECTION_NS::MemberAttributes< kTransient > m_object;
   ROOT_SELECTION_NS::MemberAttributes< kTransient > m_event;

#endif // ROOT_VERSION

};
EXIT_ROOT_SELECTION_NS

template< typename STORABLE >
bool operator==( const DataLink< STORABLE >& a,
                 const DataLink< STORABLE >& b );

template< typename STORABLE >
bool operator!=( const DataLink< STORABLE >& a,
                 const DataLink< STORABLE >& b );

// Include the implementation:
#ifndef __GCCXML__
#   include "DataLink.icc"
#endif // __GCCXML__

#endif // ATHLINKS_DATALINK_H

---