/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/xAODCore/xAODCore/tools/AuxPersVector.h

// Dear emacs, this is -*- c++ -*-
// $Id: AuxPersVector.h 785202 2016-11-18 18:42:53Z ssnyder $
#ifndef XAODCORE_AUXPERSVECTOR_H
#define XAODCORE_AUXPERSVECTOR_H

// EDM include(s):
#include "AthContainers/AuxTypeRegistry.h"
#include "AthContainers/tools/AuxTypeVector.h"
#include "AthContainersInterfaces/IAuxSetOption.h"

namespace xAOD {

   template< class T, class VEC=std::vector< T > >
   class AuxPersVector : public SG::IAuxTypeVector {

   public:
      typedef VEC& vector_type;

      AuxPersVector( vector_type vec ) : m_vec( vec ) {}

      virtual SG::IAuxTypeVector* clone() const {
        return new AuxPersVector<T, VEC>(*this);
      }

      virtual void* toPtr() {
         if (m_vec.empty())
           return 0;
         return &*m_vec.begin();
      }
      virtual void* toVector() {
         return &m_vec;
      }
      virtual size_t size() const {
         return m_vec.size();
      }
      virtual void resize( size_t sz ) {
         m_vec.resize( sz );
      }
      virtual void reserve( size_t sz ) {
         m_vec.reserve( sz );
      }
      virtual void shift( size_t pos, ptrdiff_t offs ) {
         if (offs < 0) {
            if (-offs > static_cast<off_t>(pos)) offs = -pos;
            std::copy (m_vec.begin()+pos, m_vec.end(), m_vec.begin()+pos+offs);
            m_vec.resize (m_vec.size() + offs);
         }
         else if (offs > 0) {
            size_t oldsz = m_vec.size();
            m_vec.resize (m_vec.size() + offs);
            std::copy (m_vec.rbegin()+offs, m_vec.rbegin()+offs+oldsz-pos,
                       m_vec.rbegin());
            std::fill (m_vec.begin()+pos, m_vec.begin()+pos+offs, T());
         }
      }

      virtual bool setOption (const SG::AuxDataOption& option) {
         // Need to instantiate different functions depending on whether or not
         // the payload implements @c SG::IAuxSetOption.
         // From AuxTypeVector.icc
         return DataModel_detail::setOptionHelper
            (&m_vec,
             option,
             typename std::is_base_of<SG::IAuxSetOption,vector_type>::type());
      }

     virtual const std::type_info* objType() const {
        return &typeid( VEC );
     }

   private:
      vector_type m_vec;

   }; // class AuxPersVector

} // namespace xAOD

#endif // XAODCORE_AUXPERSVECTOR_H

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