/Src/Dependencies/Boost/boost/variant/detail/move.hpp
http://hadesmem.googlecode.com/ · C++ Header · 166 lines · 80 code · 36 blank · 50 comment · 1 complexity · b9b0fe0ea7ba65249cca8accdfbd661b MD5 · raw file
- //-----------------------------------------------------------------------------
- // boost variant/detail/move.hpp header file
- // See http://www.boost.org for updates, documentation, and revision history.
- //-----------------------------------------------------------------------------
- //
- // Copyright (c) 2002-2003 Eric Friedman
- // Copyright (c) 2002 by Andrei Alexandrescu
- //
- // Use, modification and distribution are 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)
- //
- // This file derivative of MoJO. Much thanks to Andrei for his initial work.
- // See <http://www.cuj.com/experts/2102/alexandr.htm> for information on MOJO.
- // Re-issued here under the Boost Software License, with permission of the original
- // author (Andrei Alexandrescu).
- #ifndef BOOST_VARIANT_DETAIL_MOVE_HPP
- #define BOOST_VARIANT_DETAIL_MOVE_HPP
- #include <iterator> // for iterator_traits
- #include <new> // for placement new
- #include "boost/config.hpp"
- #include "boost/detail/workaround.hpp"
- #include "boost/mpl/if.hpp"
- #include "boost/type_traits/is_base_and_derived.hpp"
- namespace boost {
- namespace detail { namespace variant {
- //////////////////////////////////////////////////////////////////////////
- // forward declares
- //
- // NOTE: Incomplete until (if?) Boost.Move becomes part of Boost.
- //
- template <typename Deriving> class moveable;
- template <typename T> class move_source;
- template <typename T> class move_return;
- namespace detail {
- // (detail) moveable_tag
- //
- // Concrete type from which moveable<T> derives.
- //
- // TODO: Move into moveable_fwd.hpp and define has_move_constructor.
- //
- template <typename Deriving>
- struct moveable_tag
- {
- };
- } // namespace detail
- //////////////////////////////////////////////////////////////////////////
- // function template move
- //
- // Takes a T& and returns, if T derives moveable<T>, a move_source<T> for
- // the object; else, returns the T&.
- //
- namespace detail {
- // (detail) class template move_type
- //
- // Metafunction that, given moveable T, provides move_source<T>, else T&.
- //
- template <typename T>
- struct move_type
- {
- public: // metafunction result
- typedef typename mpl::if_<
- is_base_and_derived<detail::moveable_tag<T>, T>
- , move_source<T>
- , T&
- >::type type;
- };
- } // namespace detail
- template <typename T>
- inline
- typename detail::move_type<T>::type
- move(T& source)
- {
- typedef typename detail::move_type<T>::type
- move_t;
- return move_t(source);
- }
- //////////////////////////////////////////////////////////////////////////
- // class template return_t
- //
- // Metafunction that, given moveable T, provides move_return<T>, else T.
- //
- template <typename T>
- struct return_t
- {
- public: // metafunction result
- typedef typename mpl::if_<
- is_base_and_derived<moveable<T>, T>
- , move_return<T>
- , T
- >::type type;
- };
- //////////////////////////////////////////////////////////////////////////
- // function template move_swap
- //
- // Swaps using Koenig lookup but falls back to move-swap for primitive
- // types and on non-conforming compilers.
- //
- #if defined(BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP) \
- || BOOST_WORKAROUND(__GNUC__, BOOST_TESTED_AT(2))
- // [Indicate that move_swap by overload is disabled...]
- #define BOOST_NO_MOVE_SWAP_BY_OVERLOAD
- // [...and provide straight swap-by-move implementation:]
- template <typename T>
- inline void move_swap(T& lhs, T& rhs)
- {
- T tmp( boost::detail::variant::move(lhs) );
- lhs = boost::detail::variant::move(rhs);
- rhs = boost::detail::variant::move(tmp);
- }
- #else// !workaround
- namespace detail { namespace move_swap {
- template <typename T>
- inline void swap(T& lhs, T& rhs)
- {
- T tmp( boost::detail::variant::move(lhs) );
- lhs = boost::detail::variant::move(rhs);
- rhs = boost::detail::variant::move(tmp);
- }
- }} // namespace detail::move_swap
- template <typename T>
- inline void move_swap(T& lhs, T& rhs)
- {
- using detail::move_swap::swap;
- swap(lhs, rhs);
- }
- #endif // workaround
- }} // namespace detail::variant
- } // namespace boost
- #endif // BOOST_VARIANT_DETAIL_MOVE_HPP