text: #ifndef BOOST_SERIALIZATION_TYPE_INFO_IMPLEMENTATION_HPP
  #define BOOST_SERIALIZATION_TYPE_INFO_IMPLEMENTATION_HPP
  
  // MS compatible compilers support #pragma once
  #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  # pragma once
  #endif
  
  /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
  // type_info_implementation.hpp: interface for portable version of type_info
  
  // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 
  // Use, modification and distribution is subject to the Boost Software
  // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  // http://www.boost.org/LICENSE_1_0.txt)
  
  //  See http://www.boost.org for updates, documentation, and revision history.
  
  ///////////////////////////////////////////////////////////////////////////////
  // If no other implementation has been designated as default, 
  // use extended_type_info_typeid.hpp
  
  #ifndef BOOST_SERIALIZATION_DEFAULT_TYPE_INFO
  #include <boost/serialization/extended_type_info_typeid.hpp>
  #endif
  
  #include <boost/config.hpp>
  #include <boost/detail/workaround.hpp>
  
  #include <boost/mpl/eval_if.hpp>
  #include <boost/mpl/identity.hpp>
  #include <boost/type_traits/is_base_and_derived.hpp>
  #include <boost/serialization/traits.hpp>
  
  namespace boost {
  namespace serialization {
  
  struct basic_traits;
  
  // note that T and const T are folded into const T so that
  // there is only one table entry per type
  template<class T>
  struct type_info_implementation {
      template<class U>
      struct traits_class_typeinfo_implementation {
          typedef BOOST_DEDUCED_TYPENAME U::type_info_implementation type;
      };
      typedef 
          BOOST_DEDUCED_TYPENAME mpl::eval_if<
              boost::is_base_and_derived<basic_traits, T>,
              traits_class_typeinfo_implementation<T>,
          //else
              mpl::identity<
                  BOOST_SERIALIZATION_DEFAULT_TYPE_INFO(T)
              >
          >::type type;
  };
  
  } // namespace serialization
  } // namespace boost
  
  // define a macro to assign a particular derivation of extended_type_info
  // to a specified a class. 
  #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
  #define BOOST_CLASS_TYPE_INFO(T, ETI)              \
  namespace boost {                                  \
  namespace serialization {                          \
  template<>                                         \
  struct type_info_implementation< T > {             \
      typedef ETI type;                              \
  };                                                 \
  }                                                  \
  }                                                  \
  /**/
  #else
  #define BOOST_CLASS_TYPE_INFO(T, ETI)              \
  namespace boost {                                  \
  namespace serialization {                          \
  template<>                                         \
  struct type_info_implementation< T > {             \
      typedef ETI type;                              \
  };                                                 \
  template<>                                         \
  struct type_info_implementation< const T > {       \
      typedef ETI type;                              \
  };                                                 \
  }                                                  \
  }                                                  \
  /**/
  #endif
  
  #endif /// BOOST_SERIALIZATION_TYPE_INFO_IMPLEMENTATION_HPP
  