# persistence/persistent_interface.hpp

    #ifndef STLPLUS_PERSISTENT_INTERFACE
    #define STLPLUS_PERSISTENT_INTERFACE
    ////////////////////////////////////////////////////////////////////////////////

    //   Author:    Andy Rushton
    //   Copyright: (c) Southampton University 1999-2004
    //              (c) Andy Rushton           2004 onwards
    //   License:   BSD License, see ../docs/license.html

    //   Persistence for pointers to polymorphic classes using the interface approach.

    //   This works on a set of classes derived from a common superclass called
    //   persistent which is declared as an interface. Each subclass has a set of
    //   methods that enable clone/dump/restore operations. Each subclass must be
    //   registered with the persistence dump/restore context so that the system
    //   knows how to dump it.

    //   This approach is suited to classes that can be modified to add persistence
    //   methods. See persistent_callback for a non-invasive way of handling
    //   polymorphism.

    //   Objects are always dumped/restored as pointers to the superclass T.

    //   Multiple pointers to the same object are handled in the same way as for
    //   simple pointers

    //   Only classes registered with the context can be dumped and restored as
    //   polymorphic types - see dump_context::register_interface and
    //   restore_context::register_interface. Attempting to use any unrecognised class
    //   will throw an exception.

    ////////////////////////////////////////////////////////////////////////////////
    #include "persistence_fixes.hpp"
    #include "persistent_contexts.hpp"
    #include "persistent.hpp"

    ////////////////////////////////////////////////////////////////////////////////

    namespace stlplus
    {

      // exceptions: persistent_dump_failed
      template<typename T>
      void dump_interface(dump_context&, const T* const data);

      // exceptions: persistent_restore_failed
      template<typename T>
      void restore_interface(restore_context&, T*& data);

    } // end namespace stlplus

      ////////////////////////////////////////////////////////////////////////////////
    #include "persistent_interface.tpp"
    #endif