TPCnvList.icc

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/*
  Copyright (C) 2002-2026 CERN for the benefit of the ATLAS collaboration
*/
 
/**
 * @file AthenaPoolCnvSvc/TPCnvList.icc
 * @author scott snyder <snyder@bnl.gov>
 * @date Jan, 2016
 * @brief Helper for calling TP converters from an Athena converter.
 */
 
 
namespace AthenaPoolCnvSvc {
 
 
/**
 * @brief Read the persistent object and convert it to transient.
 * @param parent The top-level pool converter object.
 * @param key The SG key of the object being read.
 * @param msg MsgStream for error reporting.
 *
 * Returns a newly-allocated object.
 * If the type of the persistent object on the file does not match the
 * the type of any of our TP converters, return nullptr.
 * Other errors are reported by raising exceptions.
 */
template <class CNV, class TRANS, class ... TPCNVS>
std::unique_ptr<TRANS>
TPCnvList<CNV, TRANS, TPCNVS...>::createTransient (CNV& parent,
                                                   const Token* token,
                                                   const std::string& key,
                                                   MsgStream& msg)
{
  // Try createTransient on each TPCnv; stop when one succeeds.
  std::unique_ptr<TRANS> result;
  std::apply([&](auto& ... elt) {
    (void)(... || (result = elt.createTransient(parent, token, key, msg)));
  }, m_list);
  return result;
}
 
 
/**
 * @brief Read the persistent object and convert it to transient.
 * @param parent The top-level pool converter object.
 * @param trans The transient object to modify.
 * @param key The SG key of the object being read.
 * @param msg MsgStream for error reporting.
 *
 * Overwrites the provided transient object.
 * If the type of the persistent object on the file does not match the
 * the type of any of our TP converters, return false.
 * Other errors are reported by raising exceptions.
 */
template <class CNV, class TRANS, class ... TPCNVS>
bool TPCnvList<CNV, TRANS, TPCNVS...>::persToTrans (CNV& parent,
                                                    TRANS* trans,
                                                    const Token* token,
                                                    const std::string& key,
                                                    MsgStream& msg)
{
  // Try persToTrans on each TPCnv; stop when one succeeds.
  bool found = false;
  std::apply([&](auto& ... elt) {
    (void)(... || (found = elt.persToTrans(parent, trans, token, key, msg)));
  }, m_list);
  return found;
}
 
 
} // namespace AthenaPoolCnvSvc