// Copyright (C) 2005, Fernando Luis Cacciola Carballal.

 //

 // 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/lib/optional for documentation.

 //

 // You are welcome to contact the author at:

 //  fernando_cacciola@hotmail.com

 //

 #ifndef BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP

 #define BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP

 #if defined __GNUC__

 #  if (__GNUC__ == 2 && __GNUC_MINOR__ <= 97) 

 #    define BOOST_OPTIONAL_NO_TEMPLATED_STREAMS

 #  endif

 #endif // __GNUC__

 #if defined BOOST_OPTIONAL_NO_TEMPLATED_STREAMS

 #  include <iostream>

 #else 

 #  include <istream>

 #  include <ostream>

 #endif  

 #include "boost/optional/optional.hpp"

 #include "boost/utility/value_init.hpp"

 namespace boost

 {

 #if defined (BOOST_NO_TEMPLATED_STREAMS)

 template<class T>

 inline std::ostream& operator<<(std::ostream& out, optional<T> const& v)

 #else

 template<class CharType, class CharTrait, class T>

 inline

 std::basic_ostream<CharType, CharTrait>&

 operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v)

 #endif

 {

   if ( out.good() )

   {

     if ( !v )

          out << "--" ;

     else out << ' ' << *v ;

   }

   return out;

 }

 #if defined (BOOST_NO_TEMPLATED_STREAMS)

 template<class T>

 inline std::istream& operator>>(std::istream& in, optional<T>& v)

 #else

 template<class CharType, class CharTrait, class T>

 inline

 std::basic_istream<CharType, CharTrait>&

 operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v)

 #endif

 {

   if ( in.good() )

   {

     int d = in.get();

     if ( d == ' ' )

     {

       T x ;

       in >> x;

       v = x ;

     }

     else

       v = optional<T>() ;

   }

   return in;

 }

 } // namespace boost

 #endif