Chris@16: //-----------------------------------------------------------------------------
Chris@16: // boost detail/reference_content.hpp header file
Chris@16: // See http://www.boost.org for updates, documentation, and revision history.
Chris@16: //-----------------------------------------------------------------------------
Chris@16: //
Chris@16: // Copyright (c) 2003
Chris@16: // Eric Friedman
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_DETAIL_REFERENCE_CONTENT_HPP
Chris@16: #define BOOST_DETAIL_REFERENCE_CONTENT_HPP
Chris@16: 
Chris@16: #include "boost/config.hpp"
Chris@16: 
Chris@16: #   include "boost/mpl/bool.hpp"
Chris@16: #   include "boost/type_traits/has_nothrow_copy.hpp"
Chris@16: 
Chris@16: #include "boost/mpl/void.hpp"
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class template reference_content
Chris@16: //
Chris@16: // Non-Assignable wrapper for references.
Chris@16: //
Chris@16: template <typename RefT>
Chris@16: class reference_content
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     RefT content_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     ~reference_content()
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     reference_content(RefT r)
Chris@16:         : content_( r )
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     reference_content(const reference_content& operand)
Chris@16:         : content_( operand.content_ )
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: private: // non-Assignable
Chris@16: 
Chris@16:     reference_content& operator=(const reference_content&);
Chris@16: 
Chris@16: public: // queries
Chris@16: 
Chris@16:     RefT get() const
Chris@16:     {
Chris@16:         return content_;
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) metafunction make_reference_content
Chris@16: //
Chris@16: // Wraps with reference_content if specified type is reference.
Chris@16: //
Chris@16: 
Chris@16: template <typename T = mpl::void_> struct make_reference_content;
Chris@16: 
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct make_reference_content
Chris@16: {
Chris@16:     typedef T type;
Chris@16: };
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct make_reference_content< T& >
Chris@16: {
Chris@16:     typedef reference_content<T&> type;
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template <>
Chris@16: struct make_reference_content< mpl::void_ >
Chris@16: {
Chris@16:     template <typename T>
Chris@16:     struct apply
Chris@16:         : make_reference_content<T>
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     typedef mpl::void_ type;
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // reference_content<T&> type traits specializations
Chris@16: //
Chris@16: 
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct has_nothrow_copy<
Chris@16:       ::boost::detail::reference_content< T& >
Chris@16:     >
Chris@16:     : mpl::true_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_DETAIL_REFERENCE_CONTENT_HPP