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  1//===----------------------------------------------------------------------===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===----------------------------------------------------------------------===//
  8
  9#ifndef _LIBCPP___MEMORY_USES_ALLOCATOR_CONSTRUCTION_H
 10#define _LIBCPP___MEMORY_USES_ALLOCATOR_CONSTRUCTION_H
 11
 12#include <__config>
 13#include <__memory/construct_at.h>
 14#include <__memory/uses_allocator.h>
 15#include <__tuple/tuple_like_no_subrange.h>
 16#include <__type_traits/enable_if.h>
 17#include <__type_traits/remove_cv.h>
 18#include <__utility/declval.h>
 19#include <__utility/pair.h>
 20#include <tuple>
 21
 22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 23#  pragma GCC system_header
 24#endif
 25
 26_LIBCPP_PUSH_MACROS
 27#include <__undef_macros>
 28
 29_LIBCPP_BEGIN_NAMESPACE_STD
 30
 31#if _LIBCPP_STD_VER >= 17
 32
 33template <class _Tp>
 34inline constexpr bool __is_cv_std_pair = __is_pair_v<remove_cv_t<_Tp>>;
 35
 36template <class _Tp, class = void>
 37struct __uses_allocator_construction_args;
 38
 39namespace __uses_allocator_detail {
 40
 41template <class _Ap, class _Bp>
 42void __fun(const pair<_Ap, _Bp>&);
 43
 44template <class _Tp>
 45decltype(__uses_allocator_detail::__fun(std::declval<_Tp>()), true_type()) __convertible_to_const_pair_ref_impl(int);
 46
 47template <class>
 48false_type __convertible_to_const_pair_ref_impl(...);
 49
 50template <class _Tp>
 51inline constexpr bool __convertible_to_const_pair_ref =
 52    decltype(__uses_allocator_detail::__convertible_to_const_pair_ref_impl<_Tp>(0))::value;
 53
 54#  if _LIBCPP_STD_VER >= 23
 55template <class _Tp, class _Up>
 56inline constexpr bool __uses_allocator_constraints =
 57    __is_cv_std_pair<_Tp> && !__pair_like_no_subrange<_Up> && !__convertible_to_const_pair_ref<_Up>;
 58#  else
 59template <class _Tp, class _Up>
 60inline constexpr bool __uses_allocator_constraints = __is_cv_std_pair<_Tp> && !__convertible_to_const_pair_ref<_Up>;
 61#  endif
 62
 63} // namespace __uses_allocator_detail
 64
 65template <class _Type, class _Alloc, class... _Args>
 66_LIBCPP_HIDE_FROM_ABI constexpr _Type __make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args);
 67
 68template <class _Pair>
 69struct __uses_allocator_construction_args<_Pair, __enable_if_t<__is_cv_std_pair<_Pair>>> {
 70  template <class _Alloc, class _Tuple1, class _Tuple2>
 71  static _LIBCPP_HIDE_FROM_ABI constexpr auto
 72  __apply(const _Alloc& __alloc, piecewise_construct_t, _Tuple1&& __x, _Tuple2&& __y) noexcept {
 73    return std::make_tuple(
 74        piecewise_construct,
 75        std::apply(
 76            [&__alloc](auto&&... __args1) {
 77              return __uses_allocator_construction_args<typename _Pair::first_type>::__apply(
 78                  __alloc, std::forward<decltype(__args1)>(__args1)...);
 79            },
 80            std::forward<_Tuple1>(__x)),
 81        std::apply(
 82            [&__alloc](auto&&... __args2) {
 83              return __uses_allocator_construction_args<typename _Pair::second_type>::__apply(
 84                  __alloc, std::forward<decltype(__args2)>(__args2)...);
 85            },
 86            std::forward<_Tuple2>(__y)));
 87  }
 88
 89  template <class _Alloc>
 90  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc) noexcept {
 91    return __uses_allocator_construction_args<_Pair>::__apply(__alloc, piecewise_construct, tuple<>{}, tuple<>{});
 92  }
 93
 94  template <class _Alloc, class _Up, class _Vp>
 95  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, _Up&& __u, _Vp&& __v) noexcept {
 96    return __uses_allocator_construction_args<_Pair>::__apply(
 97        __alloc,
 98        piecewise_construct,
 99        std::forward_as_tuple(std::forward<_Up>(__u)),
100        std::forward_as_tuple(std::forward<_Vp>(__v)));
101  }
102
103#  if _LIBCPP_STD_VER >= 23
104  template <class _Alloc, class _Up, class _Vp>
105  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, pair<_Up, _Vp>& __pair) noexcept {
106    return __uses_allocator_construction_args<_Pair>::__apply(
107        __alloc, piecewise_construct, std::forward_as_tuple(__pair.first), std::forward_as_tuple(__pair.second));
108  }
109#  endif
110
111  template <class _Alloc, class _Up, class _Vp>
112  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, const pair<_Up, _Vp>& __pair) noexcept {
113    return __uses_allocator_construction_args<_Pair>::__apply(
114        __alloc, piecewise_construct, std::forward_as_tuple(__pair.first), std::forward_as_tuple(__pair.second));
115  }
116
117  template <class _Alloc, class _Up, class _Vp>
118  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, pair<_Up, _Vp>&& __pair) noexcept {
119    return __uses_allocator_construction_args<_Pair>::__apply(
120        __alloc,
121        piecewise_construct,
122        std::forward_as_tuple(std::get<0>(std::move(__pair))),
123        std::forward_as_tuple(std::get<1>(std::move(__pair))));
124  }
125
126#  if _LIBCPP_STD_VER >= 23
127  template <class _Alloc, class _Up, class _Vp>
128  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, const pair<_Up, _Vp>&& __pair) noexcept {
129    return __uses_allocator_construction_args<_Pair>::__apply(
130        __alloc,
131        piecewise_construct,
132        std::forward_as_tuple(std::get<0>(std::move(__pair))),
133        std::forward_as_tuple(std::get<1>(std::move(__pair))));
134  }
135
136  template < class _Alloc, __pair_like_no_subrange _PairLike>
137  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, _PairLike&& __p) noexcept {
138    return __uses_allocator_construction_args<_Pair>::__apply(
139        __alloc,
140        piecewise_construct,
141        std::forward_as_tuple(std::get<0>(std::forward<_PairLike>(__p))),
142        std::forward_as_tuple(std::get<1>(std::forward<_PairLike>(__p))));
143  }
144#  endif
145
146  template <class _Alloc,
147            class _Type,
148            __enable_if_t<__uses_allocator_detail::__uses_allocator_constraints<_Pair, _Type>, int> = 0>
149  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, _Type&& __value) noexcept {
150    struct __pair_constructor {
151      using _PairMutable = remove_cv_t<_Pair>;
152
153      _LIBCPP_HIDDEN constexpr auto __do_construct(const _PairMutable& __pair) const {
154        return std::__make_obj_using_allocator<_PairMutable>(__alloc_, __pair);
155      }
156
157      _LIBCPP_HIDDEN constexpr auto __do_construct(_PairMutable&& __pair) const {
158        return std::__make_obj_using_allocator<_PairMutable>(__alloc_, std::move(__pair));
159      }
160
161      const _Alloc& __alloc_;
162      _Type& __value_;
163
164      _LIBCPP_HIDDEN constexpr operator _PairMutable() const { return __do_construct(std::forward<_Type>(__value_)); }
165    };
166
167    return std::make_tuple(__pair_constructor{__alloc, __value});
168  }
169};
170
171template <class _Type>
172struct __uses_allocator_construction_args<_Type, __enable_if_t<!__is_cv_std_pair<_Type>>> {
173  template <class _Alloc, class... _Args>
174  static _LIBCPP_HIDE_FROM_ABI constexpr auto __apply(const _Alloc& __alloc, _Args&&... __args) noexcept {
175    if constexpr (!uses_allocator_v<remove_cv_t<_Type>, _Alloc> && is_constructible_v<_Type, _Args...>) {
176      return std::forward_as_tuple(std::forward<_Args>(__args)...);
177    } else if constexpr (uses_allocator_v<remove_cv_t<_Type>, _Alloc> &&
178                         is_constructible_v<_Type, allocator_arg_t, const _Alloc&, _Args...>) {
179      return tuple<allocator_arg_t, const _Alloc&, _Args&&...>(allocator_arg, __alloc, std::forward<_Args>(__args)...);
180    } else if constexpr (uses_allocator_v<remove_cv_t<_Type>, _Alloc> &&
181                         is_constructible_v<_Type, _Args..., const _Alloc&>) {
182      return std::forward_as_tuple(std::forward<_Args>(__args)..., __alloc);
183    } else {
184      static_assert(
185          sizeof(_Type) + 1 == 0, "If uses_allocator_v<Type> is true, the type has to be allocator-constructible");
186    }
187  }
188};
189
190template <class _Type, class _Alloc, class... _Args>
191_LIBCPP_HIDE_FROM_ABI constexpr _Type __make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args) {
192  return std::make_from_tuple<_Type>(
193      __uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...));
194}
195
196template <class _Type, class _Alloc, class... _Args>
197_LIBCPP_HIDE_FROM_ABI constexpr _Type*
198__uninitialized_construct_using_allocator(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args) {
199  return std::apply(
200      [&__ptr](auto&&... __xs) { return std::__construct_at(__ptr, std::forward<decltype(__xs)>(__xs)...); },
201      __uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...));
202}
203
204#endif // _LIBCPP_STD_VER >= 17
205
206#if _LIBCPP_STD_VER >= 20
207
208template <class _Type, class _Alloc, class... _Args>
209_LIBCPP_HIDE_FROM_ABI constexpr auto uses_allocator_construction_args(const _Alloc& __alloc, _Args&&... __args) noexcept
210    -> decltype(__uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...)) {
211  return /*--*/ __uses_allocator_construction_args<_Type>::__apply(__alloc, std::forward<_Args>(__args)...);
212}
213
214template <class _Type, class _Alloc, class... _Args>
215_LIBCPP_HIDE_FROM_ABI constexpr auto make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args)
216    -> decltype(std::__make_obj_using_allocator<_Type>(__alloc, std::forward<_Args>(__args)...)) {
217  return /*--*/ std::__make_obj_using_allocator<_Type>(__alloc, std::forward<_Args>(__args)...);
218}
219
220template <class _Type, class _Alloc, class... _Args>
221_LIBCPP_HIDE_FROM_ABI constexpr auto
222uninitialized_construct_using_allocator(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args)
223    -> decltype(std::__uninitialized_construct_using_allocator(__ptr, __alloc, std::forward<_Args>(__args)...)) {
224  return /*--*/ std::__uninitialized_construct_using_allocator(__ptr, __alloc, std::forward<_Args>(__args)...);
225}
226
227#endif // _LIBCPP_STD_VER >= 20
228
229_LIBCPP_END_NAMESPACE_STD
230
231_LIBCPP_POP_MACROS
232
233#endif // _LIBCPP___MEMORY_USES_ALLOCATOR_CONSTRUCTION_H