text: #ifndef BOOST_SERIALIZATION_ASSUME_ABSTRACT_HPP
  #define BOOST_SERIALIZATION_ASSUME_ABSTRACT_HPP
  
  // MS compatible compilers support #pragma once
  #if defined(_MSC_VER)
  # pragma once
  #endif
  
  /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
  // assume_abstract_class.hpp:
  
  // (C) Copyright 2008 Robert Ramey
  // 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.
  
  // this is useful for compilers which don't support the boost::is_abstract
  
  #include <boost/type_traits/is_abstract.hpp>
  #include <boost/mpl/bool_fwd.hpp>
  
  #ifndef BOOST_NO_IS_ABSTRACT
  
  // if there is an intrinsic is_abstract defined, we don't have to do anything
  #define BOOST_SERIALIZATION_ASSUME_ABSTRACT(T)
  
  // but forward to the "official" is_abstract
  namespace boost {
  namespace serialization {
      template<class T>
      struct is_abstract : boost::is_abstract< T > {} ;
  } // namespace serialization
  } // namespace boost
  
  #else
  // we have to "make" one
  
  namespace boost {
  namespace serialization {
      template<class T>
      struct is_abstract : boost::false_type {};
  } // namespace serialization
  } // namespace boost
  
  // define a macro to make explicit designation of this more transparent
  #define BOOST_SERIALIZATION_ASSUME_ABSTRACT(T)        \
  namespace boost {                                     \
  namespace serialization {                             \
  template<>                                            \
  struct is_abstract< T > : boost::true_type {};        \
  template<>                                            \
  struct is_abstract< const T > : boost::true_type {};  \
  }}                                                    \
  /**/
  
  #endif // BOOST_NO_IS_ABSTRACT
  
  #endif //BOOST_SERIALIZATION_ASSUME_ABSTRACT_HPP
  