text: //----------------------------------*-C++-*----------------------------------//
  // Copyright 2020 UT-Battelle, LLC, and other Celeritas developers.
  // See the top-level COPYRIGHT file for details.
  // SPDX-License-Identifier: (Apache-2.0 OR MIT)
  //---------------------------------------------------------------------------//
  //! \file Types.hh
  //! Type definitions for simulation management
  //---------------------------------------------------------------------------//
  #pragma once
  
  #include "base/OpaqueId.hh"
  
  namespace celeritas
  {
  //---------------------------------------------------------------------------//
  //! Counter for the initiating event for a track
  using EventId = OpaqueId<struct Event>;
  //! Unique ID (for an event) of a track among all primaries and secondaries
  using TrackId = OpaqueId<struct Track>;
  
  //---------------------------------------------------------------------------//
  } // namespace celeritas
  