| // Allocator traits -*- C++ -*- |
| |
| // Copyright (C) 2011-2016 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> |
| |
| #define __cpp_lib_allocator_traits_is_always_equal 201411 |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| struct __allocator_traits_base |
| { |
| template<typename _Alloc, typename _Up> |
| using __rebind = typename _Alloc::template rebind<_Up>::other; |
| |
| protected: |
| template<typename _Tp> |
| using __pointer = typename _Tp::pointer; |
| template<typename _Tp> |
| using __c_pointer = typename _Tp::const_pointer; |
| template<typename _Tp> |
| using __v_pointer = typename _Tp::void_pointer; |
| template<typename _Tp> |
| using __cv_pointer = typename _Tp::const_void_pointer; |
| template<typename _Tp> |
| using __diff_type = typename _Tp::difference_type; |
| template<typename _Tp> |
| using __size_type = typename _Tp::size_type; |
| template<typename _Tp> |
| using __pocca = typename _Tp::propagate_on_container_copy_assignment; |
| template<typename _Tp> |
| using __pocma = typename _Tp::propagate_on_container_move_assignment; |
| template<typename _Tp> |
| using __pocs = typename _Tp::propagate_on_container_swap; |
| template<typename _Tp> |
| using __equal = typename _Tp::is_always_equal; |
| }; |
| |
| template<typename _Alloc, typename _Up> |
| using __alloc_rebind = __detected_or_t_<__replace_first_arg_t, |
| __allocator_traits_base::__rebind, |
| _Alloc, _Up>; |
| |
| /** |
| * @brief Uniform interface to all allocator types. |
| * @ingroup allocators |
| */ |
| template<typename _Alloc> |
| struct allocator_traits : __allocator_traits_base |
| { |
| /// The allocator type |
| typedef _Alloc allocator_type; |
| /// The allocated type |
| typedef typename _Alloc::value_type value_type; |
| |
| /** |
| * @brief The allocator's pointer type. |
| * |
| * @c Alloc::pointer if that type exists, otherwise @c value_type* |
| */ |
| using pointer = __detected_or_t<value_type*, __pointer, _Alloc>; |
| |
| /** |
| * @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> |
| */ |
| using const_pointer |
| = __detected_or_t<__ptr_rebind<pointer, const value_type>, |
| __c_pointer, _Alloc>; |
| |
| /** |
| * @brief The allocator's void pointer type. |
| * |
| * @c Alloc::void_pointer if that type exists, otherwise |
| * <tt> pointer_traits<pointer>::rebind<void> </tt> |
| */ |
| using void_pointer |
| = __detected_or_t<__ptr_rebind<pointer, void>, __v_pointer, _Alloc>; |
| |
| /** |
| * @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> |
| */ |
| using const_void_pointer |
| = __detected_or_t<__ptr_rebind<pointer, const void>, __cv_pointer, |
| _Alloc>; |
| |
| /** |
| * @brief The allocator's difference type |
| * |
| * @c Alloc::difference_type if that type exists, otherwise |
| * <tt> pointer_traits<pointer>::difference_type </tt> |
| */ |
| using difference_type |
| = __detected_or_t<typename pointer_traits<pointer>::difference_type, |
| __diff_type, _Alloc>; |
| |
| /** |
| * @brief The allocator's size type |
| * |
| * @c Alloc::size_type if that type exists, otherwise |
| * <tt> make_unsigned<difference_type>::type </tt> |
| */ |
| using size_type |
| = __detected_or_t<typename make_unsigned<difference_type>::type, |
| __size_type, _Alloc>; |
| |
| /** |
| * @brief How the allocator is propagated on copy assignment |
| * |
| * @c Alloc::propagate_on_container_copy_assignment if that type exists, |
| * otherwise @c false_type |
| */ |
| using propagate_on_container_copy_assignment |
| = __detected_or_t<false_type, __pocca, _Alloc>; |
| |
| /** |
| * @brief How the allocator is propagated on move assignment |
| * |
| * @c Alloc::propagate_on_container_move_assignment if that type exists, |
| * otherwise @c false_type |
| */ |
| using propagate_on_container_move_assignment |
| = __detected_or_t<false_type, __pocma, _Alloc>; |
| |
| /** |
| * @brief How the allocator is propagated on swap |
| * |
| * @c Alloc::propagate_on_container_swap if that type exists, |
| * otherwise @c false_type |
| */ |
| using propagate_on_container_swap |
| = __detected_or_t<false_type, __pocs, _Alloc>; |
| |
| /** |
| * @brief Whether all instances of the allocator type compare equal. |
| * |
| * @c Alloc::is_always_equal if that type exists, |
| * otherwise @c is_empty<Alloc>::type |
| */ |
| using is_always_equal |
| = __detected_or_t<typename is_empty<_Alloc>::type, __equal, _Alloc>; |
| |
| template<typename _Tp> |
| using rebind_alloc = __alloc_rebind<_Alloc, _Tp>; |
| template<typename _Tp> |
| using rebind_traits = allocator_traits<rebind_alloc<_Tp>>; |
| |
| static_assert(!is_same<rebind_alloc<value_type>, __undefined>::value, |
| "allocator defines rebind or is like Alloc<T, Args>"); |
| |
| private: |
| template<typename _Alloc2> |
| static auto |
| _S_allocate(_Alloc2& __a, size_type __n, const_void_pointer __hint, int) |
| -> decltype(__a.allocate(__n, __hint)) |
| { return __a.allocate(__n, __hint); } |
| |
| template<typename _Alloc2> |
| static pointer |
| _S_allocate(_Alloc2& __a, size_type __n, const_void_pointer, ...) |
| { 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(...); |
| |
| using type = decltype(__test<_Alloc>(0)); |
| }; |
| |
| template<typename _Tp, typename... _Args> |
| using __has_construct |
| = typename __construct_helper<_Tp, _Args...>::type; |
| |
| template<typename _Tp, typename... _Args> |
| static _Require<__has_construct<_Tp, _Args...>> |
| _S_construct(_Alloc& __a, _Tp* __p, _Args&&... __args) |
| { __a.construct(__p, std::forward<_Args>(__args)...); } |
| |
| template<typename _Tp, typename... _Args> |
| static |
| _Require<__and_<__not_<__has_construct<_Tp, _Args...>>, |
| is_constructible<_Tp, _Args...>>> |
| _S_construct(_Alloc&, _Tp* __p, _Args&&... __args) |
| { ::new((void*)__p) _Tp(std::forward<_Args>(__args)...); } |
| |
| template<typename _Alloc2, typename _Tp> |
| static auto |
| _S_destroy(_Alloc2& __a, _Tp* __p, int) |
| -> decltype(__a.destroy(__p)) |
| { __a.destroy(__p); } |
| |
| template<typename _Alloc2, typename _Tp> |
| static void |
| _S_destroy(_Alloc2&, _Tp* __p, ...) |
| { __p->~_Tp(); } |
| |
| template<typename _Alloc2> |
| static auto |
| _S_max_size(_Alloc2& __a, int) |
| -> decltype(__a.max_size()) |
| { return __a.max_size(); } |
| |
| template<typename _Alloc2> |
| static size_type |
| _S_max_size(_Alloc2&, ...) |
| { |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 2466. allocator_traits::max_size() default behavior is incorrect |
| return __gnu_cxx::__numeric_traits<size_type>::__max |
| / sizeof(value_type); |
| } |
| |
| template<typename _Alloc2> |
| static auto |
| _S_select(_Alloc2& __a, int) |
| -> decltype(__a.select_on_container_copy_construction()) |
| { return __a.select_on_container_copy_construction(); } |
| |
| template<typename _Alloc2> |
| static _Alloc2 |
| _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, 0); } |
| |
| /** |
| * @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<typename _Tp> |
| static void destroy(_Alloc& __a, _Tp* __p) |
| { _S_destroy(__a, __p, 0); } |
| |
| /** |
| * @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) noexcept |
| { return _S_max_size(__a, 0); } |
| |
| /** |
| * @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, 0); } |
| }; |
| |
| /// Partial specialization for std::allocator. |
| template<typename _Tp> |
| struct allocator_traits<allocator<_Tp>> |
| { |
| /// The allocator type |
| using allocator_type = allocator<_Tp>; |
| /// The allocated type |
| using value_type = _Tp; |
| |
| /// The allocator's pointer type. |
| using pointer = _Tp*; |
| |
| /// The allocator's const pointer type. |
| using const_pointer = const _Tp*; |
| |
| /// The allocator's void pointer type. |
| using void_pointer = void*; |
| |
| /// The allocator's const void pointer type. |
| using const_void_pointer = const void*; |
| |
| /// The allocator's difference type |
| using difference_type = std::ptrdiff_t; |
| |
| /// The allocator's size type |
| using size_type = std::size_t; |
| |
| /// How the allocator is propagated on copy assignment |
| using propagate_on_container_copy_assignment = false_type; |
| |
| /// How the allocator is propagated on move assignment |
| using propagate_on_container_move_assignment = true_type; |
| |
| /// How the allocator is propagated on swap |
| using propagate_on_container_swap = false_type; |
| |
| /// Whether all instances of the allocator type compare equal. |
| using is_always_equal = true_type; |
| |
| template<typename _Up> |
| using rebind_alloc = allocator<_Up>; |
| |
| template<typename _Up> |
| using rebind_traits = allocator_traits<allocator<_Up>>; |
| |
| /** |
| * @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(allocator_type& __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> |
| */ |
| static pointer |
| allocate(allocator_type& __a, size_type __n, const_void_pointer __hint) |
| { return __a.allocate(__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(allocator_type& __a, pointer __p, size_type __n) |
| { __a.deallocate(__p, __n); } |
| |
| /** |
| * @brief Construct an object of type @a _Up |
| * @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> |
| */ |
| template<typename _Up, typename... _Args> |
| static void |
| construct(allocator_type& __a, _Up* __p, _Args&&... __args) |
| { __a.construct(__p, std::forward<_Args>(__args)...); } |
| |
| /** |
| * @brief Destroy an object of type @a _Up |
| * @param __a An allocator. |
| * @param __p Pointer to the object to destroy |
| * |
| * Calls @c __a.destroy(__p). |
| */ |
| template<typename _Up> |
| static void |
| destroy(allocator_type& __a, _Up* __p) |
| { __a.destroy(__p); } |
| |
| /** |
| * @brief The maximum supported allocation size |
| * @param __a An allocator. |
| * @return @c __a.max_size() |
| */ |
| static size_type |
| max_size(const allocator_type& __a) noexcept |
| { return __a.max_size(); } |
| |
| /** |
| * @brief Obtain an allocator to use when copying a container. |
| * @param __rhs An allocator. |
| * @return @c __rhs |
| */ |
| static allocator_type |
| select_on_container_copy_construction(const allocator_type& __rhs) |
| { return __rhs; } |
| }; |
| |
| |
| 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> |
| { }; |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace std |
| |
| #endif |
| #endif |
