////////////////////////////////////////////////////////////////////////////// // // (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 implements macros to define movable classes and //! move-aware functions #ifndef BOOST_MOVE_CORE_HPP #define BOOST_MOVE_CORE_HPP #ifndef BOOST_CONFIG_HPP # include #endif # #if defined(BOOST_HAS_PRAGMA_ONCE) # pragma once #endif #include #include // @cond //boost_move_no_copy_constructor_or_assign typedef //used to detect noncopyable types for other Boost libraries. #if defined(BOOST_NO_CXX11_DELETED_FUNCTIONS) || defined(BOOST_NO_CXX11_RVALUE_REFERENCES) #define BOOST_MOVE_IMPL_NO_COPY_CTOR_OR_ASSIGN(TYPE) \ private:\ TYPE(TYPE &);\ TYPE& operator=(TYPE &);\ public:\ typedef int boost_move_no_copy_constructor_or_assign; \ private:\ // #else #define BOOST_MOVE_IMPL_NO_COPY_CTOR_OR_ASSIGN(TYPE) \ public:\ TYPE(TYPE const &) = delete;\ TYPE& operator=(TYPE const &) = delete;\ public:\ typedef int boost_move_no_copy_constructor_or_assign; \ private:\ // #endif //BOOST_NO_CXX11_DELETED_FUNCTIONS // @endcond #if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED) #include #define BOOST_MOVE_TO_RV_CAST(RV_TYPE, ARG) reinterpret_cast(ARG) #define BOOST_MOVE_TO_LV_CAST(LV_TYPE, ARG) static_cast(ARG) //Move emulation rv breaks standard aliasing rules so add workarounds for some compilers #if defined(BOOST_GCC) && (BOOST_GCC >= 40400) && (BOOST_GCC < 40500) #define BOOST_RV_ATTRIBUTE_MAY_ALIAS BOOST_MAY_ALIAS #else #define BOOST_RV_ATTRIBUTE_MAY_ALIAS #endif namespace boost { ////////////////////////////////////////////////////////////////////////////// // // struct rv // ////////////////////////////////////////////////////////////////////////////// template class BOOST_RV_ATTRIBUTE_MAY_ALIAS rv : public ::boost::move_detail::if_c < ::boost::move_detail::is_class::value , T , ::boost::move_detail::nat >::type { rv(); ~rv() throw(); rv(rv const&); void operator=(rv const&); }; ////////////////////////////////////////////////////////////////////////////// // // is_rv // ////////////////////////////////////////////////////////////////////////////// namespace move_detail { template struct is_rv //Derive from integral constant because some Boost code assummes it has //a "type" internal typedef : integral_constant::value > {}; template struct is_not_rv { static const bool value = !is_rv::value; }; } //namespace move_detail { ////////////////////////////////////////////////////////////////////////////// // // has_move_emulation_enabled // ////////////////////////////////////////////////////////////////////////////// template struct has_move_emulation_enabled : ::boost::move_detail::has_move_emulation_enabled_impl {}; template struct has_move_emulation_disabled { static const bool value = !::boost::move_detail::has_move_emulation_enabled_impl::value; }; } //namespace boost { #define BOOST_RV_REF(TYPE)\ ::boost::rv< TYPE >& \ // #define BOOST_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ ::boost::rv< TYPE >& \ // #define BOOST_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ ::boost::rv< TYPE >& \ // #define BOOST_RV_REF_BEG\ ::boost::rv< \ // #define BOOST_RV_REF_END\ >& \ // #define BOOST_RV_REF_BEG_IF_CXX11 \ \ // #define BOOST_RV_REF_END_IF_CXX11 \ \ // #define BOOST_FWD_REF(TYPE)\ const 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_COPY_ASSIGN_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ const ::boost::rv< TYPE >& \ // #define BOOST_COPY_ASSIGN_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ const ::boost::rv< TYPE >& \ // #define BOOST_CATCH_CONST_RLVALUE(TYPE)\ const ::boost::rv< TYPE >& \ // namespace boost { namespace move_detail { template BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_c < ::boost::move_detail::is_lvalue_reference::value || !::boost::has_move_emulation_enabled::value , T&>::type move_return(T& x) BOOST_NOEXCEPT { return x; } template BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_c < !::boost::move_detail::is_lvalue_reference::value && ::boost::has_move_emulation_enabled::value , ::boost::rv&>::type move_return(T& x) BOOST_NOEXCEPT { return *BOOST_MOVE_TO_RV_CAST(::boost::rv*, ::boost::move_detail::addressof(x)); } template BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_c < !::boost::move_detail::is_lvalue_reference::value && ::boost::has_move_emulation_enabled::value , ::boost::rv&>::type move_return(::boost::rv& x) BOOST_NOEXCEPT { return x; } template BOOST_MOVE_FORCEINLINE T& unrv(::boost::rv &rv) BOOST_NOEXCEPT { return BOOST_MOVE_TO_LV_CAST(T&, rv); } } //namespace move_detail { } //namespace boost { #define BOOST_MOVE_RET(RET_TYPE, REF)\ boost::move_detail::move_return< RET_TYPE >(REF) // #define BOOST_MOVE_BASE(BASE_TYPE, ARG) \ ::boost::move((BASE_TYPE&)(ARG)) // #define BOOST_MOVE_TO_LV(ARG) \ ::boost::move_detail::unrv(ARG) // ////////////////////////////////////////////////////////////////////////////// // // BOOST_MOVABLE_BUT_NOT_COPYABLE // ////////////////////////////////////////////////////////////////////////////// #define BOOST_MOVABLE_BUT_NOT_COPYABLE(TYPE)\ BOOST_MOVE_IMPL_NO_COPY_CTOR_OR_ASSIGN(TYPE)\ public:\ BOOST_MOVE_FORCEINLINE operator ::boost::rv&() \ { return *BOOST_MOVE_TO_RV_CAST(::boost::rv*, this); }\ BOOST_MOVE_FORCEINLINE operator const ::boost::rv&() const \ { return *BOOST_MOVE_TO_RV_CAST(const ::boost::rv*, this); }\ private:\ // ////////////////////////////////////////////////////////////////////////////// // // BOOST_COPYABLE_AND_MOVABLE // ////////////////////////////////////////////////////////////////////////////// #define BOOST_COPYABLE_AND_MOVABLE(TYPE)\ public:\ inline TYPE& operator=(TYPE &t)\ { this->operator=(const_cast(t)); return *this;}\ public:\ inline operator ::boost::rv&() \ { return *BOOST_MOVE_TO_RV_CAST(::boost::rv*, this); }\ inline operator const ::boost::rv&() const \ { return *BOOST_MOVE_TO_RV_CAST(const ::boost::rv*, this); }\ private:\ // #define BOOST_COPYABLE_AND_MOVABLE_ALT(TYPE)\ public:\ BOOST_MOVE_FORCEINLINE operator ::boost::rv&() \ { return *BOOST_MOVE_TO_RV_CAST(::boost::rv*, this); }\ BOOST_MOVE_FORCEINLINE operator const ::boost::rv&() const \ { return *BOOST_MOVE_TO_RV_CAST(const ::boost::rv*, this); }\ private:\ // namespace boost{ namespace move_detail{ template< class T> struct forward_type { typedef const T &type; }; template< class T> struct forward_type< boost::rv > { typedef T type; }; }} #else //BOOST_NO_CXX11_RVALUE_REFERENCES //! 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)\ BOOST_MOVE_IMPL_NO_COPY_CTOR_OR_ASSIGN(TYPE)\ public:\ typedef int boost_move_emulation_t;\ private:\ // //! 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)\ // #if !defined(BOOST_MOVE_DOXYGEN_INVOKED) #define BOOST_COPYABLE_AND_MOVABLE_ALT(TYPE)\ // #endif //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED) namespace boost { //!This trait yields to a compile-time true boolean if T was marked as //!BOOST_MOVABLE_BUT_NOT_COPYABLE or BOOST_COPYABLE_AND_MOVABLE and //!rvalue references are not available on the platform. False otherwise. template struct has_move_emulation_enabled { static const bool value = false; }; template struct has_move_emulation_disabled { static const bool value = true; }; } //namespace boost{ //!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 problems with comma-separated template arguments, //!the template argument must be preceded with BOOST_RV_REF_BEG //!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 problems with comma-separated template arguments, //!the template argument must be preceded with BOOST_RV_REF_BEG //!and ended with BOOST_RV_REF_END #define BOOST_RV_REF_END\ && \ // //!This macro expands to BOOST_RV_REF_BEG if BOOST_NO_CXX11_RVALUE_REFERENCES //!is not defined, empty otherwise #define BOOST_RV_REF_BEG_IF_CXX11 \ BOOST_RV_REF_BEG \ // //!This macro expands to BOOST_RV_REF_END if BOOST_NO_CXX11_RVALUE_REFERENCES //!is not defined, empty otherwise #define BOOST_RV_REF_END_IF_CXX11 \ 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) #define BOOST_RV_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ TYPE && \ // #define BOOST_RV_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ TYPE && \ // #define BOOST_COPY_ASSIGN_REF_BEG \ const \ // #define BOOST_COPY_ASSIGN_REF_END \ & \ // #define BOOST_COPY_ASSIGN_REF_2_TEMPL_ARGS(TYPE, ARG1, ARG2)\ const TYPE & \ // #define BOOST_COPY_ASSIGN_REF_3_TEMPL_ARGS(TYPE, ARG1, ARG2, ARG3)\ const TYPE& \ // #define BOOST_CATCH_CONST_RLVALUE(TYPE)\ const TYPE & \ // #endif //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED) #if !defined(BOOST_MOVE_MSVC_AUTO_MOVE_RETURN_BUG) || defined(BOOST_MOVE_DOXYGEN_INVOKED) //!This macro is used to achieve portable move return semantics. //!The C++11 Standard allows implicit move returns when the object to be returned //!is designated by a lvalue and: //! - The criteria for elision of a copy operation are met OR //! - The criteria would be met save for the fact that the source object is a function parameter //! //!For C++11 conforming compilers this macros only yields to REF: //! return BOOST_MOVE_RET(RET_TYPE, REF); -> return REF; //! //!For compilers without rvalue references //!this macro does an explicit move if the move emulation is activated //!and the return type (RET_TYPE) is not a reference. //! //!For non-conforming compilers with rvalue references like Visual 2010 & 2012, //!an explicit move is performed if RET_TYPE is not a reference. //! //! Caution: When using this macro in non-conforming or C++03 //!compilers, a move will be performed even if the C++11 standard does not allow it //!(e.g. returning a static variable). The user is responsible for using this macro //!only to return local objects that met C++11 criteria. #define BOOST_MOVE_RET(RET_TYPE, REF)\ REF // #else //!defined(BOOST_MOVE_MSVC_AUTO_MOVE_RETURN_BUG) || defined(BOOST_MOVE_DOXYGEN_INVOKED) #include namespace boost { namespace move_detail { template BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_c < ::boost::move_detail::is_lvalue_reference::value , T&>::type move_return(T& x) BOOST_NOEXCEPT { return x; } template BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_c < !::boost::move_detail::is_lvalue_reference::value , Ret && >::type move_return(T&& t) BOOST_NOEXCEPT { return static_cast< Ret&& >(t); } } //namespace move_detail { } //namespace boost { #define BOOST_MOVE_RET(RET_TYPE, REF)\ boost::move_detail::move_return< RET_TYPE >(REF) // #endif //!defined(BOOST_MOVE_MSVC_AUTO_MOVE_RETURN_BUG) || defined(BOOST_MOVE_DOXYGEN_INVOKED) //!This macro is used to achieve portable optimal move constructors. //! //!When implementing the move constructor, in C++03 compilers the moved-from argument must be //!cast to the base type before calling `::boost::move()` due to rvalue reference limitations. //! //!In C++11 compilers the cast from a rvalue reference of a derived type to a rvalue reference of //!a base type is implicit. #define BOOST_MOVE_BASE(BASE_TYPE, ARG) \ ::boost::move((BASE_TYPE&)(ARG)) // //!This macro is used to achieve portable optimal move constructors. //! //!In C++03 mode, when accessing a member of type through a rvalue (implemented as a `rv &` type, where rv derives //!from T) triggers a potential UB as the program never creates objects of type rv. This macro casts back `rv` to //!`T&` so that access to member types are done through the original type. //! //!In C++11 compilers the cast from a rvalue reference of a derived type to a rvalue reference of //!a base type is implicit, so it's a no-op. #define BOOST_MOVE_TO_LV(ARG) ARG // namespace boost { namespace move_detail { template< class T> struct forward_type { typedef T type; }; }} #endif //BOOST_NO_CXX11_RVALUE_REFERENCES #include #endif //#ifndef BOOST_MOVE_CORE_HPP