reference_content.hpp

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