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boost/move/move.hpp

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright David Abrahams, Vicente Botet 2009.
// (C) Copyright Ion Gaztanaga 2009-2010.
// 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

#ifndef BOOST_MOVE_MOVE_HPP
#define BOOST_MOVE_MOVE_HPP

#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)

/// @cond

#include <boost/config.hpp>

#ifdef BOOST_MSVC
   #ifndef _CRT_SECURE_NO_DEPRECATE
      #define  BOOST_INTERPROCESS_CRT_SECURE_NO_DEPRECATE
      #define _CRT_SECURE_NO_DEPRECATE
   #endif
   #ifndef _SCL_SECURE_NO_WARNINGS
      #define  BOOST_INTERPROCESS_SCL_SECURE_NO_WARNINGS
      #define _SCL_SECURE_NO_WARNINGS
   #endif
   #pragma warning (push)
   #pragma warning(disable:4996)
#endif

#include <algorithm> //copy, copy_backward
#include <memory>    //uninitialized_copy
#include <iterator>  //std::iterator

#define BOOST_MOVE_AVOID_BOOST_DEPENDENCIES

//If boost dependencies are avoided include all machinery
#if !defined(BOOST_MOVE_AVOID_BOOST_DEPENDENCIES)
   #include <boost/utility/enable_if.hpp>
   #include <boost/utility/addressof.hpp>
   #include <boost/mpl/if.hpp>
   #include <boost/mpl/bool.hpp>
   #include <boost/mpl/and.hpp>
   #include <boost/mpl/not.hpp>
   #include <boost/mpl/identity.hpp>
   #include <boost/type_traits/is_class.hpp>
   #include <boost/type_traits/is_convertible.hpp>
   #include <boost/type_traits/has_trivial_destructor.hpp>
   #include <boost/type_traits/integral_constant.hpp>

   #define BOOST_MOVE_MPL_NS    ::boost::mpl
   #define BOOST_MOVE_BOOST_NS  ::boost
#else
   #define BOOST_MOVE_MPL_NS    ::boost::move_detail
   #define BOOST_MOVE_BOOST_NS  ::boost::move_detail
#endif   //#ifdef BOOST_MOVE_AVOID_BOOST_DEPENDENCIES

//Small meta-typetraits to support move
#ifdef BOOST_MOVE_AVOID_BOOST_DEPENDENCIES

   namespace boost {
   namespace move_detail {

   //if_
   template<bool C, typename T1, typename T2>
   struct if_c
   {
       typedef T1 type;
   };

   template<typename T1, typename T2>
   struct if_c<false,T1,T2>
   {
       typedef T2 type;
   };

   template<typename T1, typename T2, typename T3>
   struct if_
   {
      typedef typename if_c<0 != T1::value, T2, T3>::type type;
   };

   //enable_if_
   template <bool B, class T = void>
   struct enable_if_c
   {
      typedef T type;
   };

   template <class T>
   struct enable_if_c<false, T> {};

   template <class Cond, class T = void>
   struct enable_if : public enable_if_c<Cond::value, T> {};

   template <class Cond, class T = void>
   struct disable_if : public enable_if_c<!Cond::value, T> {};

   //integral_constant
   template<class T, T v>
   struct integral_constant
   {
      static const T value = v;
      typedef T value_type;
      typedef integral_constant<T, v> type;
   };

   //identity
   template <class T>
   struct identity
   {
      typedef T type;
   };

   //is_convertible
   template <class T, class U>
   class is_convertible
   {
      typedef char true_t;
      class false_t { char dummy[2]; };
      static true_t dispatch(U);
      static false_t dispatch(...);
      static T &trigger();
      public:
      enum { value = sizeof(dispatch(trigger())) == sizeof(true_t) };
   };

   //and_ not_
   template <typename Condition1, typename Condition2, typename Condition3 = integral_constant<bool, true> >
     struct and_
       : public integral_constant<bool, Condition1::value && Condition2::value && Condition3::value>
   {};

   template <typename Boolean>
     struct not_
       : public integral_constant<bool, !Boolean::value>
   {};

   //is_lvalue_reference
   template<class T>
   struct is_lvalue_reference
      : public integral_constant<bool, false>
   {};

   template<class T>
   struct is_lvalue_reference<T&>
      : public integral_constant<bool, true>
   {};

   //has_trivial_destructor
   template<class T>
   struct has_trivial_destructor
      : public integral_constant<bool, false>
   {};

   //addressof
   template<class T> struct addr_impl_ref
   {
      T & v_;
      inline addr_impl_ref( T & v ): v_( v ) {}
      inline operator T& () const { return v_; }

      private:
      addr_impl_ref & operator=(const addr_impl_ref &);
   };

   template<class T> struct addressof_impl
   {
      static inline T * f( T & v, long )
      {
         return reinterpret_cast<T*>(
            &const_cast<char&>(reinterpret_cast<const volatile char &>(v)));
      }

      static inline T * f( T * v, int )
      {  return v;  }
   };

   template<class T>
   inline T * addressof( T & v )
   {
      return ::boost::move_detail::addressof_impl<T>::f
         ( ::boost::move_detail::addr_impl_ref<T>( v ), 0 );
   }

   }  //namespace move_detail {
   }  //namespace boost {

#endif   //BOOST_MOVE_AVOID_BOOST_DEPENDENCIES

//Compiler workaround detection
#if !defined(BOOST_NO_RVALUE_REFERENCES)

   #if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 5) && !defined(__clang__)
      //Pre-standard rvalue binding rules
      #define BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
   #elif defined(_MSC_VER) && (_MSC_VER == 1600)
      //Standard rvalue binding rules but with some bugs
      #define BOOST_MOVE_MSVC_10_MEMBER_RVALUE_REF_BUG
      //Use standard library for MSVC to avoid namespace issues as
      //some move calls in the STL are not fully qualified.
      //#define BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE
   #endif

#endif

/// @endcond

#endif //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)

#if defined(BOOST_NO_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED)

   //Move emulation rv breaks standard aliasing rules so add workarounds for some compilers
   #if defined(__GNUC__) && (__GNUC__ >= 4)
      #define BOOST_MOVE_ATTRIBUTE_MAY_ALIAS __attribute__((__may_alias__))
   #else
      #define BOOST_MOVE_ATTRIBUTE_MAY_ALIAS
   #endif

   namespace boost {

   namespace move_detail {
      template<class T>
      struct is_class_or_union
      {
         struct twochar { char _[2]; };
         template <class U>
         static char is_class_or_union_tester(void(U::*)(void));
         template <class U>
         static twochar is_class_or_union_tester(...);
         static const bool value = sizeof(is_class_or_union_tester<T>(0)) == sizeof(char);
      };
      struct empty{};
   }

   //////////////////////////////////////////////////////////////////////////////
   //
   //                            struct rv
   //
   //////////////////////////////////////////////////////////////////////////////
   template <class T>
   class rv
      : public BOOST_MOVE_MPL_NS::if_c
         < ::boost::move_detail::is_class_or_union<T>::value
         , T
         , ::boost::move_detail::empty
         >::type
   {
      rv();
      ~rv();
      rv(rv const&);
      void operator=(rv const&);
   } BOOST_MOVE_ATTRIBUTE_MAY_ALIAS;



   //////////////////////////////////////////////////////////////////////////////
   //
   //                            move_detail::is_rv
   //
   //////////////////////////////////////////////////////////////////////////////

   namespace move_detail {

   template <class T>
   struct is_rv
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, false>
   {};

   template <class T>
   struct is_rv< rv<T> >
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, true>
   {};

   template <class T>
   struct is_rv< const rv<T> >
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, true>
   {};

   }  //namespace move_detail {

   //////////////////////////////////////////////////////////////////////////////
   //
   //                               has_move_emulation_enabled
   //
   //////////////////////////////////////////////////////////////////////////////
   template<class T>
   struct has_move_emulation_enabled
      : BOOST_MOVE_BOOST_NS::is_convertible< T, ::boost::rv<T>& >
   {};

   template<class T>
   struct has_move_emulation_enabled<T&>
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, false>
   {};

   template<class T>
   struct has_move_emulation_enabled< ::boost::rv<T> >
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, false>
   {};

   template <class T>
   struct has_move_emulation_enabled_aux
     : has_move_emulation_enabled<T> {};
    
   template <class T>
   struct has_nothrow_move
      : public BOOST_MOVE_BOOST_NS::integral_constant<bool, false>
   {};

   //////////////////////////////////////////////////////////////////////////////
   //
   //                            move()
   //
   //////////////////////////////////////////////////////////////////////////////
   
   template <class T>
   inline typename BOOST_MOVE_BOOST_NS::disable_if<has_move_emulation_enabled_aux<T>, T&>::type move(T& x)
   {
      return x;
   }

   template <class T>
   inline typename BOOST_MOVE_BOOST_NS::enable_if<has_move_emulation_enabled<T>, rv<T>&>::type move(T& x)
   {
      return *static_cast<rv<T>* >(BOOST_MOVE_BOOST_NS::addressof(x));
   }

   template <class T>
   inline typename BOOST_MOVE_BOOST_NS::enable_if<has_move_emulation_enabled<T>, rv<T>&>::type move(rv<T>& x)
   {
      return x;
   }

   #define BOOST_RV_REF(TYPE)\
      ::boost::rv< TYPE >& \
   //

   #define BOOST_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\
      ::boost::rv< TYPE<ARG1, ARG2> >& \
   //

   #define BOOST_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\
      ::boost::rv< TYPE<ARG1, ARG2, ARG3> >& \
   //

   #define BOOST_RV_REF_BEG\
      ::boost::rv<   \
   //

   #define BOOST_RV_REF_END\
      >& \
   //



   #define BOOST_FWD_REF(TYPE)\
      const TYPE & \
   //

   #define BOOST_CATCH_CONST_RLVALUE(TYPE)\
      const ::boost::rv< TYPE >& \
   //

   #define BOOST_COPY_ASSIGN_REF(TYPE)\
      const ::boost::rv< TYPE >& \
   //

   #define BOOST_COPY_ASSIGN_REF_BEG \
      const ::boost::rv<  \
   //

   #define BOOST_COPY_ASSIGN_REF_END \
      >& \
   //

   #define BOOST_MOVE_COPY_ASSIGN_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\
      const ::boost::rv< TYPE<ARG1, ARG2> >& \
   //

   #define BOOST_MOVE_COPY_ASSIGN_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\
      const ::boost::rv< TYPE<ARG1, ARG2, ARG3> >& \
   //

   //////////////////////////////////////////////////////////////////////////////
   //
   //                            forward()
   //
   //////////////////////////////////////////////////////////////////////////////

   template <class T>
   inline typename BOOST_MOVE_BOOST_NS::enable_if< ::boost::move_detail::is_rv<T>, T &>::type
      forward(const typename BOOST_MOVE_MPL_NS::identity<T>::type &x)
   {
      return const_cast<T&>(x);
   }

   template <class T>
   inline typename BOOST_MOVE_BOOST_NS::disable_if< ::boost::move_detail::is_rv<T>, const T &>::type
      forward(const typename BOOST_MOVE_MPL_NS::identity<T>::type &x)
   {
      return x;
   }

   //////////////////////////////////////////////////////////////////////////////
   //
   //                         BOOST_MOVABLE_BUT_NOT_COPYABLE
   //
   //////////////////////////////////////////////////////////////////////////////
   #define BOOST_MOVABLE_BUT_NOT_COPYABLE(TYPE)\
      private:\
      TYPE(TYPE &);\
      TYPE& operator=(TYPE &);\
      public:\
      operator ::boost::rv<TYPE>&() \
      {  return *static_cast< ::boost::rv<TYPE>* >(this);  }\
      operator const ::boost::rv<TYPE>&() const \
      {  return *static_cast<const ::boost::rv<TYPE>* >(this);  }\
      private:\
   //

   //////////////////////////////////////////////////////////////////////////////
   //
   //                         BOOST_COPYABLE_AND_MOVABLE
   //
   //////////////////////////////////////////////////////////////////////////////

   #define BOOST_COPYABLE_AND_MOVABLE(TYPE)\
      public:\
      TYPE& operator=(TYPE &t)\
      {  this->operator=(static_cast<const ::boost::rv<TYPE> &>(const_cast<const TYPE &>(t))); return *this;}\
      public:\
      operator ::boost::rv<TYPE>&() \
      {  return *static_cast< ::boost::rv<TYPE>* >(this);  }\
      operator const ::boost::rv<TYPE>&() const \
      {  return *static_cast<const ::boost::rv<TYPE>* >(this);  }\
      private:\
   //

   #define BOOST_COPYABLE_AND_MOVABLE_ALT(TYPE)\
      public:\
      operator ::boost::rv<TYPE>&() \
      {  return *static_cast< ::boost::rv<TYPE>* >(this);  }\
      operator const ::boost::rv<TYPE>&() const \
      {  return *static_cast<const ::boost::rv<TYPE>* >(this);  }\
      private:\
   //

   }  //namespace boost

#else    //BOOST_NO_RVALUE_REFERENCES

   namespace boost{

   //! By default this traits returns false. Classes with non-throwing move constructor
   //! and assignment should specialize this trait to obtain some performance improvements.
   template <class T>
   struct has_nothrow_move
      : public BOOST_MOVE_MPL_NS::integral_constant<bool, false>
   {};

   }  //      namespace boost{

   #if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
      #include <utility>

      namespace boost{

      using ::std::move;
      using ::std::forward;
      using ::std::move_backward;

      }  //namespace boost

   #else //!BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE

      #include <boost/type_traits/remove_reference.hpp>

      namespace boost {

      //////////////////////////////////////////////////////////////////////////////
      //
      //                                  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 converts T & into
         //! <i>::boost::rv<T> &</i> so that move emulation is activated.
         template <class T>
         rvalue_reference move (input_reference);

      #elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)

         //Old move approach, lvalues could bind to rvalue references
         template <class T>
         inline typename remove_reference<T>::type && move(T&& t)
         {  return t;   }

      #else //Old move

         template <class T>
         inline typename remove_reference<T>::type && move(T&& t)
         { return static_cast<typename remove_reference<T>::type &&>(t); }

      #endif   //Old move

      //////////////////////////////////////////////////////////////////////////////
      //
      //                                  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 necessary for
         //! perfect 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::rev<T> &
         //!
         //! * Else, input_reference is equal to output_reference is equal to input_reference.
         template <class T> output_reference forward(input_reference);
      #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_MPL_NS::identity<T>::type&& t)
         {  return t;   }

      #else //Old move

         //Implementation #5 from N2951, thanks to Howard Hinnant

         template <class T, class U>
         inline T&& forward(U&& t
             , typename BOOST_MOVE_BOOST_NS::enable_if_c<
               move_detail::is_lvalue_reference<T>::value ? move_detail::is_lvalue_reference<U>::value : true>::type * = 0/*
             , typename BOOST_MOVE_BOOST_NS::enable_if_c<
               move_detail::is_convertible
                  <typename remove_reference<U>::type*, typename remove_reference<T>::type*>::value>::type * = 0*/)
         { return static_cast<T&&>(t);   }

      #endif   //BOOST_MOVE_DOXYGEN_INVOKED

      }  //namespace boost {

   #endif   //#if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)

   //! This macro marks a type as movable but not copyable, disabling copy construction
   //! and assignment. The user will need to write a move constructor/assignment as explained
   //! in the documentation to fully write a movable but not copyable class.
   #define BOOST_MOVABLE_BUT_NOT_COPYABLE(TYPE)\
      public:\
      typedef int boost_move_emulation_t;\
      private:\
      TYPE(const TYPE &);\
      TYPE& operator=(const TYPE &);\
   //

   //! This macro marks a type as copyable and movable.
   //! The user will need to write a move constructor/assignment and a copy assignment
   //! as explained in the documentation to fully write a copyable and movable class.
   #define BOOST_COPYABLE_AND_MOVABLE(TYPE)\
   //

   #define BOOST_COPYABLE_AND_MOVABLE_ALT(TYPE)\
   //

   //!This macro is used to achieve portable syntax in move
   //!constructors and assignments for classes marked as
   //!BOOST_COPYABLE_AND_MOVABLE or BOOST_MOVABLE_BUT_NOT_COPYABLE
   #define BOOST_RV_REF(TYPE)\
      TYPE && \
   //

   //!This macro is used to achieve portable syntax in move
   //!constructors and assignments for template classes marked as
   //!BOOST_COPYABLE_AND_MOVABLE or BOOST_MOVABLE_BUT_NOT_COPYABLE.
   //!As macros have problem with comma-separatd template arguments,
   //!the template argument must be preceded with BOOST_RV_REF_START
   //!and ended with BOOST_RV_REF_END
   #define BOOST_RV_REF_BEG\
         \
   //

   //!This macro is used to achieve portable syntax in move
   //!constructors and assignments for template classes marked as
   //!BOOST_COPYABLE_AND_MOVABLE or BOOST_MOVABLE_BUT_NOT_COPYABLE.
   //!As macros have problem with comma-separatd template arguments,
   //!the template argument must be preceded with BOOST_RV_REF_START
   //!and ended with BOOST_RV_REF_END
   #define BOOST_RV_REF_END\
      && \

   //!This macro is used to achieve portable syntax in copy
   //!assignment for classes marked as BOOST_COPYABLE_AND_MOVABLE.
   #define BOOST_COPY_ASSIGN_REF(TYPE)\
      const TYPE & \
   //

   //! This macro is used to implement portable perfect forwarding
   //! as explained in the documentation.
   #define BOOST_FWD_REF(TYPE)\
      TYPE && \
   //


   #if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
   /// @cond

   #define BOOST_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\
      TYPE<ARG1, ARG2> && \
   //

   #define BOOST_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\
      TYPE<ARG1, ARG2, ARG3> && \
   //

   #define BOOST_COPY_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\
      const TYPE<ARG1, ARG2> & \
   //

   #define BOOST_COPY_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\
      TYPE<ARG1, ARG2, ARG3>& \
   //

   #define BOOST_CATCH_CONST_RLVALUE(TYPE)\
      const TYPE & \
   //

   /// @endcond

   #endif   //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)

#endif   //BOOST_NO_RVALUE_REFERENCES

namespace boost {

//////////////////////////////////////////////////////////////////////////////
//
//                            move_iterator
//
//////////////////////////////////////////////////////////////////////////////

//! Class template move_iterator is an iterator adaptor with the same behavior
//! as the underlying iterator except that its dereference operator implicitly
//! converts the value returned by the underlying iterator's dereference operator
//! to an rvalue reference. Some generic algorithms can be called with move
//! iterators to replace copying with moving.
template <class It>
class move_iterator
{
   public:
   typedef It                                                              iterator_type;
   typedef typename std::iterator_traits<iterator_type>::value_type        value_type;
   #if !defined(BOOST_NO_RVALUE_REFERENCES) || defined(BOOST_MOVE_DOXYGEN_INVOKED)
   typedef value_type &&                                                   reference;
   #else
   typedef typename BOOST_MOVE_MPL_NS::if_
      < ::boost::has_move_emulation_enabled<value_type>
      , ::boost::rv<value_type>&
      , value_type & >::type                                               reference;
   #endif
   typedef It                                                              pointer;
   typedef typename std::iterator_traits<iterator_type>::difference_type   difference_type;
   typedef typename std::iterator_traits<iterator_type>::iterator_category iterator_category;

   move_iterator()
   {}

   explicit move_iterator(It i)
      :  m_it(i)
   {}

   template <class U>
   move_iterator(const move_iterator<U>& u)
      :  m_it(u.base())
   {}

   iterator_type base() const
   {  return m_it;   }

   reference operator*() const
   {
      #if defined(BOOST_NO_RVALUE_REFERENCES) || defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
      return *m_it;
      #else
      return ::boost::move(*m_it);
      #endif
   }

   pointer   operator->() const
   {  return m_it;   }

   move_iterator& operator++()
   {  ++m_it; return *this;   }

   move_iterator<iterator_type>  operator++(int)
   {  move_iterator<iterator_type> tmp(*this); ++(*this); return tmp;   }

   move_iterator& operator--()
   {  --m_it; return *this;   }

   move_iterator<iterator_type>  operator--(int)
   {  move_iterator<iterator_type> tmp(*this); --(*this); return tmp;   }

   move_iterator<iterator_type>  operator+ (difference_type n) const
   {  return move_iterator<iterator_type>(m_it + n);  }

   move_iterator& operator+=(difference_type n)
   {  m_it += n; return *this;   }

   move_iterator<iterator_type>  operator- (difference_type n) const
   {  return move_iterator<iterator_type>(m_it - n);  }

   move_iterator& operator-=(difference_type n)
   {  m_it -= n; return *this;   }

   reference operator[](difference_type n) const
   {
      #if defined(BOOST_NO_RVALUE_REFERENCES) || defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
      return m_it[n];
      #else
      return ::boost::move(m_it[n]);
      #endif
   }

   friend bool operator==(const move_iterator& x, const move_iterator& y)
   {  return x.base() == y.base();  }

   friend bool operator!=(const move_iterator& x, const move_iterator& y)
   {  return x.base() != y.base();  }

   friend bool operator< (const move_iterator& x, const move_iterator& y)
   {  return x.base() < y.base();   }

   friend bool operator<=(const move_iterator& x, const move_iterator& y)
   {  return x.base() <= y.base();  }

   friend bool operator> (const move_iterator& x, const move_iterator& y)
   {  return x.base() > y.base();  }

   friend bool operator>=(const move_iterator& x, const move_iterator& y)
   {  return x.base() >= y.base();  }

   friend difference_type operator-(const move_iterator& x, const move_iterator& y)
   {  return x.base() - y.base();   }

   friend move_iterator operator+(difference_type n, const move_iterator& x)
   {  return move_iterator(x.base() + n);   }

   private:
   It m_it;
};


//is_move_iterator
namespace move_detail {

template <class I>
struct is_move_iterator
   : public BOOST_MOVE_BOOST_NS::integral_constant<bool, false>
{
};

template <class I>
struct is_move_iterator< ::boost::move_iterator<I> >
   : public BOOST_MOVE_BOOST_NS::integral_constant<bool, true>
{
};

}  //namespace move_detail {

//////////////////////////////////////////////////////////////////////////////
//
//                            move_iterator
//
//////////////////////////////////////////////////////////////////////////////

//!
//! <b>Returns</b>: move_iterator<It>(i).
template<class It>
inline move_iterator<It> make_move_iterator(const It &it)
{  return move_iterator<It>(it); }

//////////////////////////////////////////////////////////////////////////////
//
//                         back_move_insert_iterator
//
//////////////////////////////////////////////////////////////////////////////


//! A move insert iterator that move constructs elements at the
//! back of a container
template <typename C> // C models Container
class back_move_insert_iterator
   : public std::iterator<std::output_iterator_tag, void, void, void, void>
{
   C* container_m;

   public:
   typedef C                        container_type;
   typedef typename C::value_type   value_type;
   typedef typename C::reference    reference;

   explicit back_move_insert_iterator(C& x) : container_m(&x) { }

   back_move_insert_iterator& operator=(reference x)
   { container_m->push_back(boost::move(x)); return *this; }

   back_move_insert_iterator& operator=(BOOST_RV_REF(value_type) x)
   {  reference rx = x; return this->operator=(rx);  }

   back_move_insert_iterator& operator*()     { return *this; }
   back_move_insert_iterator& operator++()    { return *this; }
   back_move_insert_iterator& operator++(int) { return *this; }
};

//!
//! <b>Returns</b>: back_move_insert_iterator<C>(x).
template <typename C> // C models Container
inline back_move_insert_iterator<C> back_move_inserter(C& x)
{
   return back_move_insert_iterator<C>(x);
}

//////////////////////////////////////////////////////////////////////////////
//
//                         front_move_insert_iterator
//
//////////////////////////////////////////////////////////////////////////////

//! A move insert iterator that move constructs elements int the
//! front of a container
template <typename C> // C models Container
class front_move_insert_iterator
   : public std::iterator<std::output_iterator_tag, void, void, void, void>
{
   C* container_m;

public:
   typedef C                        container_type;
   typedef typename C::value_type   value_type;
   typedef typename C::reference    reference;

   explicit front_move_insert_iterator(C& x) : container_m(&x) { }

   front_move_insert_iterator& operator=(reference x)
   { container_m->push_front(boost::move(x)); return *this; }

   front_move_insert_iterator& operator=(BOOST_RV_REF(value_type) x)
   {  reference rx = x; return this->operator=(rx);  }

   front_move_insert_iterator& operator*()     { return *this; }
   front_move_insert_iterator& operator++()    { return *this; }
   front_move_insert_iterator& operator++(int) { return *this; }
};

//!
//! <b>Returns</b>: front_move_insert_iterator<C>(x).
template <typename C> // C models Container
inline front_move_insert_iterator<C> front_move_inserter(C& x)
{
   return front_move_insert_iterator<C>(x);
}

//////////////////////////////////////////////////////////////////////////////
//
//                         insert_move_iterator
//
//////////////////////////////////////////////////////////////////////////////
template <typename C> // C models Container
class move_insert_iterator
   : public std::iterator<std::output_iterator_tag, void, void, void, void>
{
   C* container_m;
   typename C::iterator pos_;

   public:
   typedef C                        container_type;
   typedef typename C::value_type   value_type;
   typedef typename C::reference    reference;

   explicit move_insert_iterator(C& x, typename C::iterator pos)
      : container_m(&x), pos_(pos)
   {}

   move_insert_iterator& operator=(reference x)
   {
      pos_ = container_m->insert(pos_, ::boost::move(x));
      ++pos_;
      return *this;
   }

   move_insert_iterator& operator=(BOOST_RV_REF(value_type) x)
   {  reference rx = x; return this->operator=(rx);  }

   move_insert_iterator& operator*()     { return *this; }
   move_insert_iterator& operator++()    { return *this; }
   move_insert_iterator& operator++(int) { return *this; }
};

//!
//! <b>Returns</b>: move_insert_iterator<C>(x, it).
template <typename C> // C models Container
inline move_insert_iterator<C> move_inserter(C& x, typename C::iterator it)
{
   return move_insert_iterator<C>(x, it);
}

//////////////////////////////////////////////////////////////////////////////
//
//                               move
//
//////////////////////////////////////////////////////////////////////////////

#if !defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)

   //! <b>Effects</b>: Moves elements in the range [first,last) into the range [result,result + (last -
   //!   first)) starting from first and proceeding to last. For each non-negative integer n < (last-first),
   //!   performs *(result + n) = ::boost::move (*(first + n)).
   //!
   //! <b>Effects</b>: result + (last - first).
   //!
   //! <b>Requires</b>: result shall not be in the range [first,last).
   //!
   //! <b>Complexity</b>: Exactly last - first move assignments.
   template <typename I, // I models InputIterator
            typename O> // O models OutputIterator
   O move(I f, I l, O result)
   {
      while (f != l) {
         *result = ::boost::move(*f);
         ++f; ++result;
      }
      return result;
   }

   //////////////////////////////////////////////////////////////////////////////
   //
   //                               move_backward
   //
   //////////////////////////////////////////////////////////////////////////////

   //! <b>Effects</b>: Moves elements in the range [first,last) into the range
   //!   [result - (last-first),result) starting from last - 1 and proceeding to
   //!   first. For each positive integer n <= (last - first),
   //!   performs *(result - n) = ::boost::move(*(last - n)).
   //!
   //! <b>Requires</b>: result shall not be in the range [first,last).
   //!
   //! <b>Returns</b>: result - (last - first).
   //!
   //! <b>Complexity</b>: Exactly last - first assignments.
   template <typename I, // I models BidirectionalIterator
   typename O> // O models BidirectionalIterator
   O move_backward(I f, I l, O result)
   {
      while (f != l) {
         --l; --result;
         *result = ::boost::move(*l);
      }
      return result;
   }

#endif   //!defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)

//////////////////////////////////////////////////////////////////////////////
//
//                               uninitialized_move
//
//////////////////////////////////////////////////////////////////////////////

//! <b>Effects</b>:
//!   \code
//!   for (; first != last; ++result, ++first)
//!      new (static_cast<void*>(&*result))
//!         typename iterator_traits<ForwardIterator>::value_type(boost::move(*first));
//!   \endcode
//!
//! <b>Returns</b>: result
template
   <typename I, // I models InputIterator
    typename F> // F models ForwardIterator
F uninitialized_move(I f, I l, F r
   /// @cond
//   ,typename BOOST_MOVE_BOOST_NS::enable_if<has_move_emulation_enabled<typename std::iterator_traits<I>::value_type> >::type* = 0
   /// @endcond
   )
{
   typedef typename std::iterator_traits<I>::value_type input_value_type;
   while (f != l) {
      ::new(static_cast<void*>(&*r)) input_value_type(boost::move(*f));
      ++f; ++r;
   }
   return r;
}

/// @cond
/*
template
   <typename I,   // I models InputIterator
    typename F>   // F models ForwardIterator
F uninitialized_move(I f, I l, F r,
   typename BOOST_MOVE_BOOST_NS::disable_if<has_move_emulation_enabled<typename std::iterator_traits<I>::value_type> >::type* = 0)
{
   return std::uninitialized_copy(f, l, r);
}
*/

//////////////////////////////////////////////////////////////////////////////
//
//                            uninitialized_copy_or_move
//
//////////////////////////////////////////////////////////////////////////////

namespace move_detail {

template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F uninitialized_move_move_iterator(I f, I l, F r
//                             ,typename BOOST_MOVE_BOOST_NS::enable_if< has_move_emulation_enabled<typename I::value_type> >::type* = 0
)
{
   return ::boost::uninitialized_move(f, l, r);
}
/*
template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
F uninitialized_move_move_iterator(I f, I l, F r,
                                   typename BOOST_MOVE_BOOST_NS::disable_if< has_move_emulation_enabled<typename I::value_type> >::type* = 0)
{
   return std::uninitialized_copy(f.base(), l.base(), r);
}
*/
}  //namespace move_detail {

template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F uninitialized_copy_or_move(I f, I l, F r,
                             typename BOOST_MOVE_BOOST_NS::enable_if< move_detail::is_move_iterator<I> >::type* = 0)
{
   return ::boost::move_detail::uninitialized_move_move_iterator(f, l, r);
}

//////////////////////////////////////////////////////////////////////////////
//
//                            copy_or_move
//
//////////////////////////////////////////////////////////////////////////////

namespace move_detail {

template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F move_move_iterator(I f, I l, F r
//                             ,typename BOOST_MOVE_BOOST_NS::enable_if< has_move_emulation_enabled<typename I::value_type> >::type* = 0
)
{
   return ::boost::move(f, l, r);
}
/*
template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
F move_move_iterator(I f, I l, F r,
                                   typename BOOST_MOVE_BOOST_NS::disable_if< has_move_emulation_enabled<typename I::value_type> >::type* = 0)
{
   return std::copy(f.base(), l.base(), r);
}
*/

}  //namespace move_detail {

template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F copy_or_move(I f, I l, F r,
                             typename BOOST_MOVE_BOOST_NS::enable_if< move_detail::is_move_iterator<I> >::type* = 0)
{
   return ::boost::move_detail::move_move_iterator(f, l, r);
}

/// @endcond

//! <b>Effects</b>:
//!   \code
//!   for (; first != last; ++result, ++first)
//!      new (static_cast<void*>(&*result))
//!         typename iterator_traits<ForwardIterator>::value_type(*first);
//!   \endcode
//!
//! <b>Returns</b>: result
//!
//! <b>Note</b>: This function is provided because
//!   <i>std::uninitialized_copy</i> from some STL implementations
//!    is not compatible with <i>move_iterator</i>
template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F uninitialized_copy_or_move(I f, I l, F r
   /// @cond
   ,typename BOOST_MOVE_BOOST_NS::disable_if< move_detail::is_move_iterator<I> >::type* = 0
   /// @endcond
   )
{
   return std::uninitialized_copy(f, l, r);
}

//! <b>Effects</b>:
//!   \code
//!   for (; first != last; ++result, ++first)
//!      *result = *first;
//!   \endcode
//!
//! <b>Returns</b>: result
//!
//! <b>Note</b>: This function is provided because
//!   <i>std::uninitialized_copy</i> from some STL implementations
//!    is not compatible with <i>move_iterator</i>
template
<typename I,   // I models InputIterator
typename F>   // F models ForwardIterator
inline F copy_or_move(I f, I l, F r
   /// @cond
   ,typename BOOST_MOVE_BOOST_NS::disable_if< move_detail::is_move_iterator<I> >::type* = 0
   /// @endcond
   )
{
   return std::copy(f, l, r);
}

//! If this trait yields to true
//! (<i>has_trivial_destructor_after_move &lt;T&gt;::value == true</i>)
//! means that if T is used as argument of a move construction/assignment,
//! there is no need to call T's destructor.
//! This optimization tipically is used to improve containers' performance.
//!
//! By default this trait is true if the type has trivial destructor,
//! every class should specialize this trait if it wants to improve performance
//! when inserted in containers.
template <class T>
struct has_trivial_destructor_after_move
   : BOOST_MOVE_BOOST_NS::has_trivial_destructor<T>
{};



namespace move_detail {

// Code from Jeffrey Lee Hellrung, many thanks

#ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T> struct forward_type { typedef T type; };
#else // #ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T>
   struct forward_type
   { typedef const T &type; };

   template< class T>
   struct forward_type< boost::rv<T> >
   { typedef T type; };
#endif // #ifndef BOOST_NO_RVALUE_REFERENCES



// Code from Jeffrey Lee Hellrung, many thanks

template< class T > struct is_rvalue_reference : BOOST_MOVE_BOOST_NS::integral_constant<bool, false> { };
#ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T > struct is_rvalue_reference< T&& > : BOOST_MOVE_BOOST_NS::integral_constant<bool, true> { };
#else // #ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T > struct is_rvalue_reference< boost::rv<T>& >
      :  BOOST_MOVE_BOOST_NS::integral_constant<bool, true>
   {};

   template< class T > struct is_rvalue_reference< const boost::rv<T>& >
      : BOOST_MOVE_BOOST_NS::integral_constant<bool, true>
   {};
#endif // #ifndef BOOST_NO_RVALUE_REFERENCES

#ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T > struct add_rvalue_reference { typedef T&& type; };
#else // #ifndef BOOST_NO_RVALUE_REFERENCES
   namespace detail_add_rvalue_reference
   {
      template< class T
              , bool emulation = ::boost::has_move_emulation_enabled<T>::value
              , bool rv        = ::boost::move_detail::is_rv<T>::value  >
      struct add_rvalue_reference_impl { typedef T type; };

      template< class T, bool emulation>
      struct add_rvalue_reference_impl< T, emulation, true > { typedef T & type; };

      template< class T, bool rv >
      struct add_rvalue_reference_impl< T, true, rv > { typedef ::boost::rv<T>& type; };
   } // namespace detail_add_rvalue_reference

   template< class T >
   struct add_rvalue_reference
      : detail_add_rvalue_reference::add_rvalue_reference_impl<T>
   { };

   template< class T >
   struct add_rvalue_reference<T &>
   {  typedef T & type; };

#endif // #ifndef BOOST_NO_RVALUE_REFERENCES

template< class T > struct remove_rvalue_reference { typedef T type; };

#ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T > struct remove_rvalue_reference< T&& >                  { typedef T type; };
#else // #ifndef BOOST_NO_RVALUE_REFERENCES
   template< class T > struct remove_rvalue_reference< rv<T> >                { typedef T type; };
   template< class T > struct remove_rvalue_reference< const rv<T> >          { typedef T type; };
   template< class T > struct remove_rvalue_reference< volatile rv<T> >       { typedef T type; };
   template< class T > struct remove_rvalue_reference< const volatile rv<T> > { typedef T type; };
   template< class T > struct remove_rvalue_reference< rv<T>& >               { typedef T type; };
   template< class T > struct remove_rvalue_reference< const rv<T>& >         { typedef T type; };
   template< class T > struct remove_rvalue_reference< volatile rv<T>& >      { typedef T type; };
   template< class T > struct remove_rvalue_reference< const volatile rv<T>& >{ typedef T type; };
#endif // #ifndef BOOST_NO_RVALUE_REFERENCES

template <typename T>
typename boost::move_detail::add_rvalue_reference<T>::type declval();

}
// Ideas from Boost.Move review, Jeffrey Lee Hellrung:
//
//- TypeTraits metafunctions is_lvalue_reference, add_lvalue_reference, and remove_lvalue_reference ?
//  Perhaps add_reference and remove_reference can be modified so that they behave wrt emulated rvalue
//  references the same as wrt real rvalue references, i.e., add_reference< rv<T>& > -> T& rather than
//  rv<T>& (since T&& & -> T&).
//
//- Add'l TypeTraits has_[trivial_]move_{constructor,assign}...?
//
//- An as_lvalue(T& x) function, which amounts to an identity operation in C++0x, but strips emulated
//  rvalue references in C++03.  This may be necessary to prevent "accidental moves".

}  //namespace boost {

#if defined BOOST_MSVC
   #pragma warning (pop)
   #ifdef BOOST_INTERPROCESS_CRT_SECURE_NO_DEPRECATE
      #undef BOOST_INTERPROCESS_CRT_SECURE_NO_DEPRECATE
      #undef _CRT_SECURE_NO_DEPRECATE
   #endif

   #ifdef BOOST_INTERPROCESS_SCL_SECURE_NO_WARNINGS
      #undef BOOST_INTERPROCESS_SCL_SECURE_NO_WARNINGS
      #undef _SCL_SECURE_NO_WARNINGS
   #endif
#endif

#endif //#ifndef BOOST_MOVE_MOVE_HPP