boost/interprocess/detail/move.hpp
////////////////////////////////////////////////////////////////////////////// // // (C) Copyright David Abrahams, Vicente Botet, Ion Gaztanaga 2009. // 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. // ////////////////////////////////////////////////////////////////////////////// // // Parts of this file come from Adobe's Move library: // // Copyright 2005-2007 Adobe Systems Incorporated // Distributed under the MIT License (see accompanying file LICENSE_1_0_0.txt // or a copy at http://stlab.adobe.com/licenses.html) // ////////////////////////////////////////////////////////////////////////////// //! \file #ifndef BOOST_MOVE_HPP #define BOOST_MOVE_HPP #include <boost/config.hpp> #include <algorithm> //copy, copy_backward #include <memory> //uninitialized_copy #include <iterator> //std::iterator #include <boost/mpl/if.hpp> #include <boost/utility/enable_if.hpp> #include <boost/mpl/bool.hpp> #include <boost/type_traits/has_trivial_destructor.hpp> #include <boost/utility/addressof.hpp> /// @cond namespace boost { namespace interprocess { namespace move_detail { template <class T> struct identity { typedef T type; }; 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) }; }; } //namespace interprocess { } //namespace move_detail { } //namespace boost { /// @endcond #if !defined(BOOST_HAS_RVALUE_REFS) && !defined(BOOST_MOVE_DOXYGEN_INVOKED) //#define BOOST_MOVE_ASSIGN_FROM_NON_CONST_RVALUE namespace boost { namespace interprocess { ////////////////////////////////////////////////////////////////////////////// // // struct rv // ////////////////////////////////////////////////////////////////////////////// template <class T> class rv : public T { rv(); ~rv(); rv(rv const&); void operator=(rv const&); }; ////////////////////////////////////////////////////////////////////////////// // // move_detail::is_rv // ////////////////////////////////////////////////////////////////////////////// namespace move_detail { template <class T> struct is_rv { static const bool value = false; }; template <class T> struct is_rv< rv<T> > { static const bool value = true; }; } //namespace move_detail { ////////////////////////////////////////////////////////////////////////////// // // is_movable // ////////////////////////////////////////////////////////////////////////////// template<class T> class is_movable : public ::boost::mpl::bool_<move_detail::is_convertible<T, rv<T>&>::value> { }; template<class T> class is_movable< rv<T> > : public ::boost::mpl::bool_<false> { }; template <class T> struct has_nothrow_move : is_movable<T> {}; ////////////////////////////////////////////////////////////////////////////// // // move() // ////////////////////////////////////////////////////////////////////////////// template <class T> typename ::boost::disable_if<is_movable<T>, T&>::type move(T& x) { return x; } template <class T> typename enable_if<is_movable<T>, rv<T>&>::type move(T& x) { return *static_cast<rv<T>* >(boost::addressof(x)); } template <class T> typename enable_if<is_movable<T>, rv<T>&>::type move(rv<T>& x) { return x; } ////////////////////////////////////////////////////////////////////////////// // // forward() // ////////////////////////////////////////////////////////////////////////////// template <class T> typename enable_if< ::boost::interprocess::move_detail::is_rv<T>, T &>::type forward(const typename move_detail::identity<T>::type &x) { return const_cast<T&>(x); } template <class T> typename disable_if< ::boost::interprocess::move_detail::is_rv<T>, const T &>::type forward(const typename move_detail::identity<T>::type &x) { return x; } #define BOOST_INTERPROCESS_RV_REF(TYPE)\ ::boost::interprocess::rv< TYPE >& \ // #define BOOST_INTERPROCESS_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ ::boost::interprocess::rv< TYPE<ARG1, ARG2> >& \ // #define BOOST_INTERPROCESS_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ ::boost::interprocess::rv< TYPE<ARG1, ARG2, ARG3> >& \ // #ifdef BOOST_MOVE_ASSIGN_FROM_NON_CONST_RVALUE #define BOOST_INTERPROCESS_COPY_ASSIGN_REF(TYPE)\ const ::boost::interprocess::rv< TYPE >& \ // #define BOOST_INTERPROCESS_COPY_ASSIGN_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ const ::boost::interprocess::rv< TYPE<ARG1, ARG2> >& \ // #define BOOST_INTERPROCESS_COPY_ASSIGN_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ const ::boost::interprocess::rv< TYPE<ARG1, ARG2, ARG3> >& \ // #else //BOOST_MOVE_ASSIGN_FROM_NON_CONST_RVALUE #define BOOST_INTERPROCESS_COPY_ASSIGN_REF(TYPE)\ const TYPE & \ // #define BOOST_INTERPROCESS_COPY_ASSIGN_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ const TYPE< ARG1, ARG2 >& \ // #define BOOST_INTERPROCESS_COPY_ASSIGN_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ const TYPE< ARG1, ARG2, ARG3 > & \ // #endif #define BOOST_INTERPROCESS_FWD_REF(TYPE)\ const TYPE & \ // #define BOOST_INTERPROCESS_CATCH_CONST_RLVALUE(TYPE)\ const ::boost::interprocess::rv< TYPE >& \ // ////////////////////////////////////////////////////////////////////////////// // // BOOST_INTERPROCESS_MOVABLE_BUT_NOT_COPYABLE // ////////////////////////////////////////////////////////////////////////////// #define BOOST_INTERPROCESS_MOVABLE_BUT_NOT_COPYABLE(TYPE)\ private:\ TYPE(TYPE &);\ TYPE& operator=(TYPE &);\ public:\ operator ::boost::interprocess::rv<TYPE>&() \ { return *reinterpret_cast< ::boost::interprocess::rv<TYPE>* >(this); }\ operator const ::boost::interprocess::rv<TYPE>&() const \ { return *reinterpret_cast<const ::boost::interprocess::rv<TYPE>* >(this); }\ private:\ // ////////////////////////////////////////////////////////////////////////////// // // BOOST_COPYABLE_AND_MOVABLE // ////////////////////////////////////////////////////////////////////////////// #ifdef BOOST_MOVE_ASSIGN_FROM_NON_CONST_RVALUE #define BOOST_COPYABLE_AND_MOVABLE(TYPE)\ public:\ TYPE& operator=(TYPE &t)\ { this->operator=(static_cast<const ::boost::interprocess::rv<TYPE> &>(const_cast<const TYPE &>(t))); return *this;}\ public:\ operator ::boost::interprocess::rv<TYPE>&() \ { return *reinterpret_cast< ::boost::interprocess::rv<TYPE>* >(this); }\ operator const ::boost::interprocess::rv<TYPE>&() const \ { return *reinterpret_cast<const ::boost::interprocess::rv<TYPE>* >(this); }\ private:\ // #else //#ifdef BOOST_MOVE_ASSIGN_FROM_NON_CONST_RVALUE #define BOOST_COPYABLE_AND_MOVABLE(TYPE)\ public:\ operator ::boost::interprocess::rv<TYPE>&() \ { return *reinterpret_cast< ::boost::interprocess::rv<TYPE>* >(this); }\ operator const ::boost::interprocess::rv<TYPE>&() const \ { return *reinterpret_cast<const ::boost::interprocess::rv<TYPE>* >(this); }\ private:\ // #endif } //namespace interprocess { } //namespace boost #else //BOOST_HAS_RVALUE_REFS #include <boost/type_traits/remove_reference.hpp> namespace boost { namespace interprocess { /// @cond namespace move_detail { typedef char one; struct two {one _[2];}; template <class T> struct internal_member_value_traits { template <class U> static one test(...); template <class U> static two test(typename U::boost_move_emulation_t* = 0); static const bool value = sizeof(test<T>(0)) == sizeof(two); }; } //namespace move_detail { /// @endcond ////////////////////////////////////////////////////////////////////////////// // // is_movable // ////////////////////////////////////////////////////////////////////////////// //! For compilers with rvalue references, this traits class returns true //! if BOOST_ENABLE_MOVE_EMULATION is activated. //! //! For other compilers returns true if T is convertible to <i>::boost::interprocess::rv<T>&</i> template<class T> class is_movable : public ::boost::mpl::bool_<move_detail::internal_member_value_traits<T>::value> { }; //! For compilers with rvalue references, this traits class returns true //! if T && is convertible to T. //! //! For other compilers returns true if T has implemented move emulation. template <class T> struct has_nothrow_move : is_movable<T> {}; ////////////////////////////////////////////////////////////////////////////// // // move // ////////////////////////////////////////////////////////////////////////////// #if defined(BOOST_MOVE_DOXYGEN_INVOKED) //! This function provides a way to convert a reference into a rvalue reference //! in compilers with rvalue reference. For other compilers converts T & into //! <i>::boost::interprocess::rv<T> &</i> so that move emulation is activated. template <class T> inline rvalue_reference move (input_reference); #else template <class T> inline typename remove_reference<T>::type&& move(T&& t) { return t; } #endif ////////////////////////////////////////////////////////////////////////////// // // 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::interprocess::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> inline output_reference forward(input_reference); #else template <class T> inline T&& forward (typename move_detail::identity<T>::type&& t) { return t; } #endif ////////////////////////////////////////////////////////////////////////////// // // BOOST_ENABLE_MOVE_EMULATION // ////////////////////////////////////////////////////////////////////////////// ///@cond #define BOOST_ENABLE_MOVE_EMULATION(TYPE)\ typedef int boost_move_emulation_t; \ // /// @endcond //! 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_INTERPROCESS_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)\ typedef int boost_move_emulation_t; // /// @cond #define BOOST_INTERPROCESS_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ TYPE<ARG1, ARG2> && \ // #define BOOST_INTERPROCESS_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ TYPE<ARG1, ARG2, ARG3> && \ // /// @endcond //!This macro is used to achieve portable syntax in move //!constructors and assignments for classes marked as //!BOOST_COPYABLE_AND_MOVABLE or BOOST_INTERPROCESS_MOVABLE_BUT_NOT_COPYABLE #define BOOST_INTERPROCESS_RV_REF(TYPE)\ TYPE && \ // //!This macro is used to achieve portable syntax in copy //!assignment for classes marked as BOOST_COPYABLE_AND_MOVABLE. #define BOOST_INTERPROCESS_COPY_ASSIGN_REF(TYPE)\ const TYPE & \ // /// @cond #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>& \ // /// @endcond //! This macro is used to implement portable perfect forwarding //! as explained in the documentation. #define BOOST_INTERPROCESS_FWD_REF(TYPE)\ TYPE && \ // #define BOOST_INTERPROCESS_CATCH_CONST_RLVALUE(TYPE)\ const TYPE & \ // } //namespace interprocess { } //namespace boost { #endif //BOOST_HAS_RVALUE_REFS namespace boost { namespace interprocess { ////////////////////////////////////////////////////////////////////////////// // // 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_HAS_RVALUE_REFS) || defined(BOOST_MOVE_DOXYGEN_INVOKED) typedef value_type && reference; #else typedef typename ::boost::mpl::if_ < ::boost::interprocess::is_movable<value_type> , ::boost::interprocess::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_HAS_RVALUE_REFS) return *m_it; #else return ::boost::interprocess::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_HAS_RVALUE_REFS) return m_it[n]; #else return ::boost::interprocess::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::mpl::bool_<false> { }; template <class I> struct is_move_iterator< ::boost::interprocess::move_iterator<I> > : public ::boost::mpl::bool_<true> { }; } //namespace move_detail { ////////////////////////////////////////////////////////////////////////////// // // move_iterator // ////////////////////////////////////////////////////////////////////////////// //! //! <b>Returns</b>: move_iterator<It>(i). template<class It> 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; explicit back_move_insert_iterator(C& x) : container_m(&x) { } back_move_insert_iterator& operator=(typename C::reference x) { container_m->push_back(boost::interprocess::move(x)); return *this; } 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; explicit front_move_insert_iterator(C& x) : container_m(&x) { } front_move_insert_iterator& operator=(typename C::reference x) { container_m->push_front(boost::interprocess::move(x)); return *this; } 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; explicit move_insert_iterator(C& x, typename C::iterator pos) : container_m(&x), pos_(pos) {} move_insert_iterator& operator=(typename C::reference x) { pos_ = container_m->insert(pos_, ::boost::interprocess::move(x)); ++pos_; return *this; } 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 // ////////////////////////////////////////////////////////////////////////////// //! <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::interprocess::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::interprocess::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::interprocess::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::interprocess::move(*l); } return result; } ////////////////////////////////////////////////////////////////////////////// // // uninitialized_move // ////////////////////////////////////////////////////////////////////////////// //! <b>Effects</b>: //! \code //! for (; first != last; ++result, ++first) //! new (static_cast<void*>(&*result)) //! typename iterator_traits<ForwardIterator>::value_type(boost::interprocess::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 enable_if<is_movable<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::interprocess::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 disable_if<is_movable<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 F uninitialized_move_move_iterator(I f, I l, F r, typename enable_if< is_movable<typename I::value_type> >::type* = 0) { return ::boost::interprocess::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 disable_if< is_movable<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 F uninitialized_copy_or_move(I f, I l, F r, typename enable_if< move_detail::is_move_iterator<I> >::type* = 0) { return ::boost::interprocess::move_detail::uninitialized_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 F uninitialized_copy_or_move(I f, I l, F r /// @cond ,typename disable_if< move_detail::is_move_iterator<I> >::type* = 0 /// @endcond ) { return std::uninitialized_copy(f, l, r); } //! If this trait yields to true //! (<i>has_trivial_destructor_after_move_ctor <T>::value == true</i>) //! means that if T is used as argument of a move construction, //! 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_ctor : public ::boost::has_trivial_destructor<T> {}; //! If this trait yields to true //! (<i>has_trivial_destructor_after_move <T>::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 : public ::boost::has_trivial_destructor<T> {}; //! If this trait yields to true //! (<i>has_trivial_destructor_after_move_to_moved <T>::value == true</i>) //! means that if t1 of type T is being moved to an already moved value t2, //! there is no need to call t1's destructor: //! <pre> //! T t1, t2, t3(::boost::interprocess::move(t2)); //! t2 = ::boost::interprocess::move(t1); //! //There is no need to call t1's destructor //! </pre> //! This optimization 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_to_moved : public has_trivial_destructor_after_move<T> {}; } //namespace interprocess { } //namespace boost { #endif //#ifndef BOOST_MOVE_HPP