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// Allocator traits -*- C++ -*- // Copyright (C) 2011-2013 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/alloc_traits.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{memory} */ #ifndef _ALLOC_TRAITS_H #define _ALLOC_TRAITS_H 1 #if __cplusplus >= 201103L #include <bits/memoryfwd.h> #include <bits/ptr_traits.h> #include <ext/numeric_traits.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Alloc, typename _Tp> class __alloctr_rebind_helper { template<typename _Alloc2, typename _Tp2> static constexpr bool _S_chk(typename _Alloc2::template rebind<_Tp2>::other*) { return true; } template<typename, typename> static constexpr bool _S_chk(...) { return false; } public: static const bool __value = _S_chk<_Alloc, _Tp>(nullptr); }; template<typename _Alloc, typename _Tp> const bool __alloctr_rebind_helper<_Alloc, _Tp>::__value; template<typename _Alloc, typename _Tp, bool = __alloctr_rebind_helper<_Alloc, _Tp>::__value> struct __alloctr_rebind; template<typename _Alloc, typename _Tp> struct __alloctr_rebind<_Alloc, _Tp, true> { typedef typename _Alloc::template rebind<_Tp>::other __type; }; template<template<typename, typename...> class _Alloc, typename _Tp, typename _Up, typename... _Args> struct __alloctr_rebind<_Alloc<_Up, _Args...>, _Tp, false> { typedef _Alloc<_Tp, _Args...> __type; }; /** * @brief Uniform interface to all allocator types. * @ingroup allocators */ template<typename _Alloc> struct allocator_traits { /// The allocator type typedef _Alloc allocator_type; /// The allocated type typedef typename _Alloc::value_type value_type; #define _GLIBCXX_ALLOC_TR_NESTED_TYPE(_NTYPE, _ALT) \ private: \ template<typename _Tp> \ static typename _Tp::_NTYPE _S_##_NTYPE##_helper(_Tp*); \ static _ALT _S_##_NTYPE##_helper(...); \ typedef decltype(_S_##_NTYPE##_helper((_Alloc*)0)) __##_NTYPE; \ public: _GLIBCXX_ALLOC_TR_NESTED_TYPE(pointer, value_type*) /** * @brief The allocator's pointer type. * * @c Alloc::pointer if that type exists, otherwise @c value_type* */ typedef __pointer pointer; _GLIBCXX_ALLOC_TR_NESTED_TYPE(const_pointer, typename pointer_traits<pointer>::template rebind<const value_type>) /** * @brief The allocator's const pointer type. * * @c Alloc::const_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<const value_type> </tt> */ typedef __const_pointer const_pointer; _GLIBCXX_ALLOC_TR_NESTED_TYPE(void_pointer, typename pointer_traits<pointer>::template rebind<void>) /** * @brief The allocator's void pointer type. * * @c Alloc::void_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<void> </tt> */ typedef __void_pointer void_pointer; _GLIBCXX_ALLOC_TR_NESTED_TYPE(const_void_pointer, typename pointer_traits<pointer>::template rebind<const void>) /** * @brief The allocator's const void pointer type. * * @c Alloc::const_void_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<const void> </tt> */ typedef __const_void_pointer const_void_pointer; _GLIBCXX_ALLOC_TR_NESTED_TYPE(difference_type, typename pointer_traits<pointer>::difference_type) /** * @brief The allocator's difference type * * @c Alloc::difference_type if that type exists, otherwise * <tt> pointer_traits<pointer>::difference_type </tt> */ typedef __difference_type difference_type; _GLIBCXX_ALLOC_TR_NESTED_TYPE(size_type, typename make_unsigned<difference_type>::type) /** * @brief The allocator's size type * * @c Alloc::size_type if that type exists, otherwise * <tt> make_unsigned<difference_type>::type </tt> */ typedef __size_type size_type; _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_copy_assignment, false_type) /** * @brief How the allocator is propagated on copy assignment * * @c Alloc::propagate_on_container_copy_assignment if that type exists, * otherwise @c false_type */ typedef __propagate_on_container_copy_assignment propagate_on_container_copy_assignment; _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_move_assignment, false_type) /** * @brief How the allocator is propagated on move assignment * * @c Alloc::propagate_on_container_move_assignment if that type exists, * otherwise @c false_type */ typedef __propagate_on_container_move_assignment propagate_on_container_move_assignment; _GLIBCXX_ALLOC_TR_NESTED_TYPE(propagate_on_container_swap, false_type) /** * @brief How the allocator is propagated on swap * * @c Alloc::propagate_on_container_swap if that type exists, * otherwise @c false_type */ typedef __propagate_on_container_swap propagate_on_container_swap; #undef _GLIBCXX_ALLOC_TR_NESTED_TYPE template<typename _Tp> using rebind_alloc = typename __alloctr_rebind<_Alloc, _Tp>::__type; template<typename _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>; private: template<typename _Alloc2> struct __allocate_helper { template<typename _Alloc3, typename = decltype(std::declval<_Alloc3*>()->allocate( std::declval<size_type>(), std::declval<const_void_pointer>()))> static true_type __test(int); template<typename> static false_type __test(...); typedef decltype(__test<_Alloc>(0)) type; static const bool value = type::value; }; template<typename _Alloc2> static typename enable_if<__allocate_helper<_Alloc2>::value, pointer>::type _S_allocate(_Alloc2& __a, size_type __n, const_void_pointer __hint) { return __a.allocate(__n, __hint); } template<typename _Alloc2> static typename enable_if<!__allocate_helper<_Alloc2>::value, pointer>::type _S_allocate(_Alloc2& __a, size_type __n, ...) { return __a.allocate(__n); } template<typename _Tp, typename... _Args> struct __construct_helper { template<typename _Alloc2, typename = decltype(std::declval<_Alloc2*>()->construct( std::declval<_Tp*>(), std::declval<_Args>()...))> static true_type __test(int); template<typename> static false_type __test(...); typedef decltype(__test<_Alloc>(0)) type; static const bool value = type::value; }; template<typename _Tp, typename... _Args> static typename enable_if<__construct_helper<_Tp, _Args...>::value, void>::type _S_construct(_Alloc& __a, _Tp* __p, _Args&&... __args) { __a.construct(__p, std::forward<_Args>(__args)...); } template<typename _Tp, typename... _Args> static typename enable_if<__and_<__not_<__construct_helper<_Tp, _Args...>>, is_constructible<_Tp, _Args...>>::value, void>::type _S_construct(_Alloc&, _Tp* __p, _Args&&... __args) { ::new((void*)__p) _Tp(std::forward<_Args>(__args)...); } template<typename _Tp> struct __destroy_helper { template<typename _Alloc2, typename = decltype(std::declval<_Alloc2*>()->destroy( std::declval<_Tp*>()))> static true_type __test(int); template<typename> static false_type __test(...); typedef decltype(__test<_Alloc>(0)) type; static const bool value = type::value; }; template<typename _Tp> static typename enable_if<__destroy_helper<_Tp>::value, void>::type _S_destroy(_Alloc& __a, _Tp* __p) { __a.destroy(__p); } template<typename _Tp> static typename enable_if<!__destroy_helper<_Tp>::value, void>::type _S_destroy(_Alloc&, _Tp* __p) { __p->~_Tp(); } template<typename _Alloc2> struct __maxsize_helper { template<typename _Alloc3, typename = decltype(std::declval<_Alloc3*>()->max_size())> static true_type __test(int); template<typename> static false_type __test(...); typedef decltype(__test<_Alloc2>(0)) type; static const bool value = type::value; }; template<typename _Alloc2> static typename enable_if<__maxsize_helper<_Alloc2>::value, size_type>::type _S_max_size(_Alloc2& __a) { return __a.max_size(); } template<typename _Alloc2> static typename enable_if<!__maxsize_helper<_Alloc2>::value, size_type>::type _S_max_size(_Alloc2&) { return __gnu_cxx::__numeric_traits<size_type>::__max; } template<typename _Alloc2> struct __select_helper { template<typename _Alloc3, typename = decltype(std::declval<_Alloc3*>() ->select_on_container_copy_construction())> static true_type __test(int); template<typename> static false_type __test(...); typedef decltype(__test<_Alloc2>(0)) type; static const bool value = type::value; }; template<typename _Alloc2> static typename enable_if<__select_helper<_Alloc2>::value, _Alloc2>::type _S_select(_Alloc2& __a) { return __a.select_on_container_copy_construction(); } template<typename _Alloc2> static typename enable_if<!__select_helper<_Alloc2>::value, _Alloc2>::type _S_select(_Alloc2& __a) { return __a; } public: /** * @brief Allocate memory. * @param __a An allocator. * @param __n The number of objects to allocate space for. * * Calls @c a.allocate(n) */ static pointer allocate(_Alloc& __a, size_type __n) { return __a.allocate(__n); } /** * @brief Allocate memory. * @param __a An allocator. * @param __n The number of objects to allocate space for. * @param __hint Aid to locality. * @return Memory of suitable size and alignment for @a n objects * of type @c value_type * * Returns <tt> a.allocate(n, hint) </tt> if that expression is * well-formed, otherwise returns @c a.allocate(n) */ static pointer allocate(_Alloc& __a, size_type __n, const_void_pointer __hint) { return _S_allocate(__a, __n, __hint); } /** * @brief Deallocate memory. * @param __a An allocator. * @param __p Pointer to the memory to deallocate. * @param __n The number of objects space was allocated for. * * Calls <tt> a.deallocate(p, n) </tt> */ static void deallocate(_Alloc& __a, pointer __p, size_type __n) { __a.deallocate(__p, __n); } /** * @brief Construct an object of type @a _Tp * @param __a An allocator. * @param __p Pointer to memory of suitable size and alignment for Tp * @param __args Constructor arguments. * * Calls <tt> __a.construct(__p, std::forward<Args>(__args)...) </tt> * if that expression is well-formed, otherwise uses placement-new * to construct an object of type @a _Tp at location @a __p from the * arguments @a __args... */ template<typename _Tp, typename... _Args> static auto construct(_Alloc& __a, _Tp* __p, _Args&&... __args) -> decltype(_S_construct(__a, __p, std::forward<_Args>(__args)...)) { _S_construct(__a, __p, std::forward<_Args>(__args)...); } /** * @brief Destroy an object of type @a _Tp * @param __a An allocator. * @param __p Pointer to the object to destroy * * Calls @c __a.destroy(__p) if that expression is well-formed, * otherwise calls @c __p->~_Tp() */ template <class _Tp> static void destroy(_Alloc& __a, _Tp* __p) { _S_destroy(__a, __p); } /** * @brief The maximum supported allocation size * @param __a An allocator. * @return @c __a.max_size() or @c numeric_limits<size_type>::max() * * Returns @c __a.max_size() if that expression is well-formed, * otherwise returns @c numeric_limits<size_type>::max() */ static size_type max_size(const _Alloc& __a) { return _S_max_size(__a); } /** * @brief Obtain an allocator to use when copying a container. * @param __rhs An allocator. * @return @c __rhs.select_on_container_copy_construction() or @a __rhs * * Returns @c __rhs.select_on_container_copy_construction() if that * expression is well-formed, otherwise returns @a __rhs */ static _Alloc select_on_container_copy_construction(const _Alloc& __rhs) { return _S_select(__rhs); } }; template<typename _Alloc> template<typename _Alloc2> const bool allocator_traits<_Alloc>::__allocate_helper<_Alloc2>::value; template<typename _Alloc> template<typename _Tp, typename... _Args> const bool allocator_traits<_Alloc>::__construct_helper<_Tp, _Args...>::value; template<typename _Alloc> template<typename _Tp> const bool allocator_traits<_Alloc>::__destroy_helper<_Tp>::value; template<typename _Alloc> template<typename _Alloc2> const bool allocator_traits<_Alloc>::__maxsize_helper<_Alloc2>::value; template<typename _Alloc> template<typename _Alloc2> const bool allocator_traits<_Alloc>::__select_helper<_Alloc2>::value; template<typename _Alloc> inline void __do_alloc_on_copy(_Alloc& __one, const _Alloc& __two, true_type) { __one = __two; } template<typename _Alloc> inline void __do_alloc_on_copy(_Alloc&, const _Alloc&, false_type) { } template<typename _Alloc> inline void __alloc_on_copy(_Alloc& __one, const _Alloc& __two) { typedef allocator_traits<_Alloc> __traits; typedef typename __traits::propagate_on_container_copy_assignment __pocca; __do_alloc_on_copy(__one, __two, __pocca()); } template<typename _Alloc> inline _Alloc __alloc_on_copy(const _Alloc& __a) { typedef allocator_traits<_Alloc> __traits; return __traits::select_on_container_copy_construction(__a); } template<typename _Alloc> inline void __do_alloc_on_move(_Alloc& __one, _Alloc& __two, true_type) { __one = std::move(__two); } template<typename _Alloc> inline void __do_alloc_on_move(_Alloc&, _Alloc&, false_type) { } template<typename _Alloc> inline void __alloc_on_move(_Alloc& __one, _Alloc& __two) { typedef allocator_traits<_Alloc> __traits; typedef typename __traits::propagate_on_container_move_assignment __pocma; __do_alloc_on_move(__one, __two, __pocma()); } template<typename _Alloc> inline void __do_alloc_on_swap(_Alloc& __one, _Alloc& __two, true_type) { using std::swap; swap(__one, __two); } template<typename _Alloc> inline void __do_alloc_on_swap(_Alloc&, _Alloc&, false_type) { } template<typename _Alloc> inline void __alloc_on_swap(_Alloc& __one, _Alloc& __two) { typedef allocator_traits<_Alloc> __traits; typedef typename __traits::propagate_on_container_swap __pocs; __do_alloc_on_swap(__one, __two, __pocs()); } template<typename _Alloc> class __is_copy_insertable_impl { typedef allocator_traits<_Alloc> _Traits; template<typename _Up, typename = decltype(_Traits::construct(std::declval<_Alloc&>(), std::declval<_Up*>(), std::declval<const _Up&>()))> static true_type _M_select(int); template<typename _Up> static false_type _M_select(...); public: typedef decltype(_M_select<typename _Alloc::value_type>(0)) type; }; // true if _Alloc::value_type is CopyInsertable into containers using _Alloc template<typename _Alloc> struct __is_copy_insertable : __is_copy_insertable_impl<_Alloc>::type { }; // std::allocator<_Tp> just requires CopyConstructible template<typename _Tp> struct __is_copy_insertable<allocator<_Tp>> : is_copy_constructible<_Tp> { }; // Used to allow copy construction of unordered containers template<bool> struct __allow_copy_cons { }; // Used to delete copy constructor of unordered containers template<> struct __allow_copy_cons<false> { __allow_copy_cons() = default; __allow_copy_cons(const __allow_copy_cons&) = delete; __allow_copy_cons(__allow_copy_cons&&) = default; __allow_copy_cons& operator=(const __allow_copy_cons&) = default; __allow_copy_cons& operator=(__allow_copy_cons&&) = default; }; template<typename _Alloc> using __check_copy_constructible = __allow_copy_cons<__is_copy_insertable<_Alloc>::value>; _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif #endif