#ifndef  BOOST_SERIALIZATION_UTILITY_HPP

 #define BOOST_SERIALIZATION_UTILITY_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

 // serialization/utility.hpp:

 // serialization for stl utility templates

 // (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.

 #include <utility>

 #include <boost/config.hpp>

 #include <boost/type_traits/remove_const.hpp>

 #include <boost/serialization/nvp.hpp>

 namespace boost { 

 namespace serialization {

 // pair

 template<class Archive, class F, class S>

 inline void serialize(

     Archive & ar,

     std::pair<F, S> & p,

     const unsigned int /* file_version */

 ){

     // note: we remove any const-ness on the first argument.  The reason is that 

     // for stl maps, the type saved is pair<const key, T).  We remove

     // the const-ness in order to be able to load it.

     typedef BOOST_DEDUCED_TYPENAME boost::remove_const<F>::type typef;

     ar & boost::serialization::make_nvp("first", const_cast<typef &>(p.first));

     ar & boost::serialization::make_nvp("second", p.second);

 }

 } // serialization

 } // namespace boost

 #endif // BOOST_SERIALIZATION_UTILITY_HPP