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+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2012-2012.
+// 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)
+//
+// See http://www.boost.org/libs/move for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+//! \file
+//! This header defines core utilities to ease the development
+//! of move-aware functions. This header minimizes dependencies
+//! from other libraries.
+
+#ifndef BOOST_MOVE_MOVE_UTILITY_CORE_HPP
+#define BOOST_MOVE_MOVE_UTILITY_CORE_HPP
+
+#include <boost/move/detail/config_begin.hpp>
+#include <boost/move/core.hpp>
+#include <boost/move/detail/meta_utils.hpp>
+#include <boost/static_assert.hpp>
+
+#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED)
+
+ namespace boost {
+
+ template<class T>
+ struct enable_move_utility_emulation
+ {
+ static const bool value = true;
+ };
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // move()
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value && !has_move_emulation_enabled<T>::value, T&>::type
+ move(T& x) BOOST_NOEXCEPT
+ {
+ return x;
+ }
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value && has_move_emulation_enabled<T>::value, rv<T>&>::type
+ move(T& x) BOOST_NOEXCEPT
+ {
+ return *static_cast<rv<T>* >(::boost::move_detail::addressof(x));
+ }
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value && has_move_emulation_enabled<T>::value, rv<T>&>::type
+ move(rv<T>& x) BOOST_NOEXCEPT
+ {
+ return x;
+ }
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // forward()
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value && ::boost::move_detail::is_rv<T>::value, T &>::type
+ forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
+ {
+ return const_cast<T&>(x);
+ }
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value && !::boost::move_detail::is_rv<T>::value, const T &>::type
+ forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
+ {
+ return x;
+ }
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // move_if_not_lvalue_reference()
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value &&
+ ::boost::move_detail::is_rv<T>::value
+ , T &>::type
+ move_if_not_lvalue_reference(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
+ {
+ return const_cast<T&>(x);
+ }
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value &&
+ !::boost::move_detail::is_rv<T>::value &&
+ (::boost::move_detail::is_lvalue_reference<T>::value ||
+ !has_move_emulation_enabled<T>::value)
+ , typename ::boost::move_detail::add_lvalue_reference<T>::type
+ >::type
+ move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type &x) BOOST_NOEXCEPT
+ {
+ return x;
+ }
+
+ template <class T>
+ inline typename ::boost::move_detail::enable_if_c
+ < enable_move_utility_emulation<T>::value &&
+ !::boost::move_detail::is_rv<T>::value &&
+ (!::boost::move_detail::is_lvalue_reference<T>::value &&
+ has_move_emulation_enabled<T>::value)
+ , rv<T>&
+ >::type
+ move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type &x) BOOST_NOEXCEPT
+ {
+ return move(x);
+ }
+
+ } //namespace boost
+
+#else //#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED)
+
+ #if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
+ #include <utility>
+
+ namespace boost{
+
+ using ::std::move;
+ using ::std::forward;
+
+ } //namespace boost
+
+ #else //!BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE
+
+ namespace boost {
+
+ //! This trait's internal boolean `value` is false in compilers with rvalue references
+ //! and true in compilers without rvalue references.
+ //!
+ //! A user can specialize this trait for a type T to false to SFINAE out `move` and `forward`
+ //! so that the user can define a different move emulation for that type in namespace boost
+ //! (e.g. another Boost library for its types) and avoid any overload ambiguity.
+ template<class T>
+ struct enable_move_utility_emulation
+ {
+ static const bool value = false;
+ };
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // move
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+ #if defined(BOOST_MOVE_DOXYGEN_INVOKED)
+ //! This function provides a way to convert a reference into a rvalue reference
+ //! in compilers with rvalue references. For other compilers if `T` is Boost.Move
+ //! enabled type then it converts `T&` into <tt>::boost::rv<T> &</tt> so that
+ //! move emulation is activated, else it returns `T &`.
+ template <class T>
+ rvalue_reference move(input_reference) noexcept;
+
+ #elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
+
+ //Old move approach, lvalues could bind to rvalue references
+ template <class T>
+ inline typename ::boost::move_detail::remove_reference<T>::type && move(T&& t) BOOST_NOEXCEPT
+ { return t; }
+
+ #else //BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
+
+ template <class T>
+ inline typename ::boost::move_detail::remove_reference<T>::type && move(T&& t) BOOST_NOEXCEPT
+ { return static_cast<typename ::boost::move_detail::remove_reference<T>::type &&>(t); }
+
+ #endif //BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // forward
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+
+ #if defined(BOOST_MOVE_DOXYGEN_INVOKED)
+ //! This function provides limited form of forwarding that is usually enough for
+ //! in-place construction and avoids the exponential overloading for
+ //! achieve the limited forwarding in C++03.
+ //!
+ //! For compilers with rvalue references this function provides perfect forwarding.
+ //!
+ //! Otherwise:
+ //! * If input_reference binds to const ::boost::rv<T> & then it output_reference is
+ //! ::boost::rv<T> &
+ //!
+ //! * Else, output_reference is equal to input_reference.
+ template <class T> output_reference forward(input_reference) noexcept;
+ #elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
+
+ //Old move approach, lvalues could bind to rvalue references
+
+ template <class T>
+ inline T&& forward(typename ::boost::move_detail::identity<T>::type&& t) BOOST_NOEXCEPT
+ { return t; }
+
+ #else //Old move
+
+ template <class T>
+ inline T&& forward(typename ::boost::move_detail::remove_reference<T>::type& t) BOOST_NOEXCEPT
+ { return static_cast<T&&>(t); }
+
+ template <class T>
+ inline T&& forward(typename ::boost::move_detail::remove_reference<T>::type&& t) BOOST_NOEXCEPT
+ {
+ //"boost::forward<T> error: 'T' is a lvalue reference, can't forward as rvalue.";
+ BOOST_STATIC_ASSERT(!boost::move_detail::is_lvalue_reference<T>::value);
+ return static_cast<T&&>(t);
+ }
+
+ #endif //BOOST_MOVE_DOXYGEN_INVOKED
+
+ //////////////////////////////////////////////////////////////////////////////
+ //
+ // move_if_not_lvalue_reference
+ //
+ //////////////////////////////////////////////////////////////////////////////
+
+
+ #if defined(BOOST_MOVE_DOXYGEN_INVOKED)
+ template <class T> output_reference move_if_not_lvalue_reference(input_reference) noexcept;
+ #elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
+
+ //Old move approach, lvalues could bind to rvalue references
+
+ template <class T>
+ inline T&& move_if_not_lvalue_reference(typename ::boost::move_detail::identity<T>::type&& t) BOOST_NOEXCEPT
+ { return t; }
+
+ #else //Old move
+
+ template <class T>
+ inline T&& move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type& t) BOOST_NOEXCEPT
+ { return static_cast<T&&>(t); }
+
+ template <class T>
+ inline T&& move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type&& t) BOOST_NOEXCEPT
+ {
+ //"boost::forward<T> error: 'T' is a lvalue reference, can't forward as rvalue.";
+ BOOST_STATIC_ASSERT(!boost::move_detail::is_lvalue_reference<T>::value);
+ return static_cast<T&&>(t);
+ }
+
+ #endif //BOOST_MOVE_DOXYGEN_INVOKED
+
+ } //namespace boost {
+
+ #endif //#if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
+
+#endif //BOOST_NO_CXX11_RVALUE_REFERENCES
+
+#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
+
+namespace boost{
+namespace move_detail{
+
+template<class T>
+void swap(T &a, T &b)
+{
+ T c((::boost::move(a)));
+ a = ::boost::move(b);
+ b = ::boost::move(c);
+}
+
+template <typename T>
+typename boost::move_detail::add_rvalue_reference<T>::type declval();
+
+} //namespace move_detail{
+} //namespace boost{
+
+#endif //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
+
+
+#include <boost/move/detail/config_end.hpp>
+
+#endif //#ifndef BOOST_MOVE_MOVE_UTILITY_CORE_HPP
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