1 // Copyright (C) 2003, Fernando Luis Cacciola Carballal.

     2 // Copyright (C) 2007, Anthony Williams

     3 // Copyright (C) 2007, Steven Watanabe, Richard Smith

     4 //

     5 // Distributed under the Boost Software License, Version 1.0.

     6 // (See accompanying file LICENSE_1_0.txt or copy at

     7 // http://www.boost.org/LICENSE_1_0.txt)

     8 //

     9 // See http://www.boost.org/lib/optional/ for documentation.

    10 //

    11 // You are welcome to contact the author at:

    12 // fernando.cacciola@gmail.com

    13 //

    14 #ifndef BOOST_NONE_17SEP2003_HPP

    15 #define BOOST_NONE_17SEP2003_HPP

    16 

    17 namespace boost

    18 {

    19   namespace detail

    20   {

    21     class none_helper;

    22   }

    23 

    24   inline void none(detail::none_helper);

    25 

    26   namespace detail

    27   {

    28     class none_helper

    29     {

    30     private:

    31       

    32       none_helper( none_helper const& ) {}

    33       

    34       friend void boost::none(none_helper);

    35     };

    36   }

    37 

    38   typedef void (*none_t)(detail::none_helper);

    39 

    40   inline void none(detail::none_helper) {}

    41 }

    42 

    43 #endif