SpecRegistry.h

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/*
 *   Copyright (C) 2002-2026 CERN for the benefit of the ATLAS collaboration
 */
#ifndef GLOBALSIM_SPECREGISTRY_H
#define GLOBALSIM_SPECREGISTRY_H
 
/*
  Turns the name of a BitSpec into the pair of functions that pack and unpack
  it. TOBTextReader and TOBTextWriter both take the name as a property and ask
  for it here, so a TOB type becomes usable in both directions at once.
 
  Which specs exist is not stated in this package's C++ any more. A spec becomes
  usable by being listed in GlobalSimulation/selection.xml, which is also what
  the dictionary is generated from; the functions are then built from the type
  name through the ROOT interpreter the first time that name is asked for, and
  kept. Adding a TOB type touches the header that defines it and the two files
  next to it, and nothing here.
 
  Keeping the layout behind a std::function means neither algorithm is a class
  template: there is one component per algorithm however many specs exist, and
  the spec is chosen at configuration time rather than at compile time.
*/
 
#include "AthContainers/AuxElement.h"
 
#include <cstddef>
#include <functional>
#include <string>
 
namespace GlobalSim {
 
  struct SpecEntry {
    std::size_t width{0};

    std::function<std::string(const SG::AuxElement&)> pack;

    std::function<void(SG::AuxElement&, const std::string&)> unpack;
  };

  const SpecEntry* specEntry(const std::string& name, std::string& error);

  std::string knownSpecNames();
 
}
 
#endif // GLOBALSIM_SPECREGISTRY_H