williamr@2: // Copyright (C) 2003, Fernando Luis Cacciola Carballal.
williamr@2: // Copyright (C) 2007, Anthony Williams
williamr@2: // Copyright (C) 2007, Steven Watanabe, Richard Smith
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0.
williamr@2: // (See accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: //
williamr@2: // See http://www.boost.org/lib/optional/ for documentation.
williamr@2: //
williamr@2: // You are welcome to contact the author at:
williamr@2: // fernando.cacciola@gmail.com
williamr@2: //
williamr@2: #ifndef BOOST_NONE_17SEP2003_HPP
williamr@2: #define BOOST_NONE_17SEP2003_HPP
williamr@2: 
williamr@2: namespace boost
williamr@2: {
williamr@2:   namespace detail
williamr@2:   {
williamr@2:     class none_helper;
williamr@2:   }
williamr@2: 
williamr@2:   inline void none(detail::none_helper);
williamr@2: 
williamr@2:   namespace detail
williamr@2:   {
williamr@2:     class none_helper
williamr@2:     {
williamr@2:     private:
williamr@2:       
williamr@2:       none_helper( none_helper const& ) {}
williamr@2:       
williamr@2:       friend void boost::none(none_helper);
williamr@2:     };
williamr@2:   }
williamr@2: 
williamr@2:   typedef void (*none_t)(detail::none_helper);
williamr@2: 
williamr@2:   inline void none(detail::none_helper) {}
williamr@2: }
williamr@2: 
williamr@2: #endif