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 <__type_traits/enable_if.h>
16#include <__type_traits/is_same.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_BEGIN_NAMESPACE_STD
27
28#if _LIBCPP_STD_VER >= 17
29
30template <class _Type>
31inline constexpr bool __is_std_pair = false;
32
33template <class _Type1, class _Type2>
34inline constexpr bool __is_std_pair<pair<_Type1, _Type2>> = true;
35
36template <class _Type, class _Alloc, class... _Args, __enable_if_t<!__is_std_pair<_Type>, int> = 0>
37_LIBCPP_HIDE_FROM_ABI constexpr auto
38__uses_allocator_construction_args(const _Alloc& __alloc, _Args&&... __args) noexcept {
39  if constexpr (!uses_allocator_v<_Type, _Alloc> && is_constructible_v<_Type, _Args...>) {
40    return std::forward_as_tuple(std::forward<_Args>(__args)...);
41  } else if constexpr (uses_allocator_v<_Type, _Alloc> &&
42                       is_constructible_v<_Type, allocator_arg_t, const _Alloc&, _Args...>) {
43    return tuple<allocator_arg_t, const _Alloc&, _Args&&...>(allocator_arg, __alloc, std::forward<_Args>(__args)...);
44  } else if constexpr (uses_allocator_v<_Type, _Alloc> && is_constructible_v<_Type, _Args..., const _Alloc&>) {
45    return std::forward_as_tuple(std::forward<_Args>(__args)..., __alloc);
46  } else {
47    static_assert(
48        sizeof(_Type) + 1 == 0, "If uses_allocator_v<Type> is true, the type has to be allocator-constructible");
49  }
50}
51
52template <class _Pair, class _Alloc, class _Tuple1, class _Tuple2, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
53_LIBCPP_HIDE_FROM_ABI constexpr auto __uses_allocator_construction_args(
54    const _Alloc& __alloc, piecewise_construct_t, _Tuple1&& __x, _Tuple2&& __y) noexcept {
55  return std::make_tuple(
56      piecewise_construct,
57      std::apply(
58          [&__alloc](auto&&... __args1) {
59            return std::__uses_allocator_construction_args<typename _Pair::first_type>(
60                __alloc, std::forward<decltype(__args1)>(__args1)...);
61          },
62          std::forward<_Tuple1>(__x)),
63      std::apply(
64          [&__alloc](auto&&... __args2) {
65            return std::__uses_allocator_construction_args<typename _Pair::second_type>(
66                __alloc, std::forward<decltype(__args2)>(__args2)...);
67          },
68          std::forward<_Tuple2>(__y)));
69}
70
71template <class _Pair, class _Alloc, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
72_LIBCPP_HIDE_FROM_ABI constexpr auto __uses_allocator_construction_args(const _Alloc& __alloc) noexcept {
73  return std::__uses_allocator_construction_args<_Pair>(__alloc, piecewise_construct, tuple<>{}, tuple<>{});
74}
75
76template <class _Pair, class _Alloc, class _Up, class _Vp, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
77_LIBCPP_HIDE_FROM_ABI constexpr auto
78__uses_allocator_construction_args(const _Alloc& __alloc, _Up&& __u, _Vp&& __v) noexcept {
79  return std::__uses_allocator_construction_args<_Pair>(
80      __alloc,
81      piecewise_construct,
82      std::forward_as_tuple(std::forward<_Up>(__u)),
83      std::forward_as_tuple(std::forward<_Vp>(__v)));
84}
85
86#  if _LIBCPP_STD_VER > 20
87template <class _Pair, class _Alloc, class _Up, class _Vp, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
88_LIBCPP_HIDE_FROM_ABI constexpr auto
89__uses_allocator_construction_args(const _Alloc& __alloc, pair<_Up, _Vp>& __pair) noexcept {
90  return std::__uses_allocator_construction_args<_Pair>(
91      __alloc, piecewise_construct, std::forward_as_tuple(__pair.first), std::forward_as_tuple(__pair.second));
92}
93#  endif
94
95template <class _Pair, class _Alloc, class _Up, class _Vp, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
96_LIBCPP_HIDE_FROM_ABI constexpr auto
97__uses_allocator_construction_args(const _Alloc& __alloc, const pair<_Up, _Vp>& __pair) noexcept {
98  return std::__uses_allocator_construction_args<_Pair>(
99      __alloc, piecewise_construct, std::forward_as_tuple(__pair.first), std::forward_as_tuple(__pair.second));
100}
101
102template <class _Pair, class _Alloc, class _Up, class _Vp, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
103_LIBCPP_HIDE_FROM_ABI constexpr auto
104__uses_allocator_construction_args(const _Alloc& __alloc, pair<_Up, _Vp>&& __pair) noexcept {
105  return std::__uses_allocator_construction_args<_Pair>(
106      __alloc,
107      piecewise_construct,
108      std::forward_as_tuple(std::get<0>(std::move(__pair))),
109      std::forward_as_tuple(std::get<1>(std::move(__pair))));
110}
111
112#  if _LIBCPP_STD_VER > 20
113template <class _Pair, class _Alloc, class _Up, class _Vp, __enable_if_t<__is_std_pair<_Pair>, int> = 0>
114_LIBCPP_HIDE_FROM_ABI constexpr auto
115__uses_allocator_construction_args(const _Alloc& __alloc, const pair<_Up, _Vp>&& __pair) noexcept {
116  return std::__uses_allocator_construction_args<_Pair>(
117      __alloc,
118      piecewise_construct,
119      std::forward_as_tuple(std::get<0>(std::move(__pair))),
120      std::forward_as_tuple(std::get<1>(std::move(__pair))));
121}
122#  endif
123
124namespace __uses_allocator_detail {
125
126template <class _Ap, class _Bp>
127void __fun(const pair<_Ap, _Bp>&);
128
129template <class _Tp>
130decltype(__uses_allocator_detail::__fun(std::declval<_Tp>()), true_type()) __convertible_to_const_pair_ref_impl(int);
131
132template <class>
133false_type __convertible_to_const_pair_ref_impl(...);
134
135template <class _Tp>
136inline constexpr bool __convertible_to_const_pair_ref =
137    decltype(__uses_allocator_detail::__convertible_to_const_pair_ref_impl<_Tp>(0))::value;
138
139} // namespace __uses_allocator_detail
140
141template <
142    class _Pair,
143    class _Alloc,
144    class _Type,
145    __enable_if_t<__is_std_pair<_Pair> && !__uses_allocator_detail::__convertible_to_const_pair_ref<_Type>, int> = 0>
146_LIBCPP_HIDE_FROM_ABI constexpr auto
147__uses_allocator_construction_args(const _Alloc& __alloc, _Type&& __value) noexcept;
148
149template <class _Type, class _Alloc, class... _Args>
150_LIBCPP_HIDE_FROM_ABI constexpr _Type __make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args);
151
152template <class _Pair,
153          class _Alloc,
154          class _Type,
155          __enable_if_t<__is_std_pair<_Pair> && !__uses_allocator_detail::__convertible_to_const_pair_ref<_Type>, int>>
156_LIBCPP_HIDE_FROM_ABI constexpr auto
157__uses_allocator_construction_args(const _Alloc& __alloc, _Type&& __value) noexcept {
158  struct __pair_constructor {
159    using _PairMutable = remove_cv_t<_Pair>;
160
161    _LIBCPP_HIDE_FROM_ABI constexpr auto __do_construct(const _PairMutable& __pair) const {
162      return std::__make_obj_using_allocator<_PairMutable>(__alloc_, __pair);
163    }
164
165    _LIBCPP_HIDE_FROM_ABI constexpr auto __do_construct(_PairMutable&& __pair) const {
166      return std::__make_obj_using_allocator<_PairMutable>(__alloc_, std::move(__pair));
167    }
168
169    const _Alloc& __alloc_;
170    _Type& __value_;
171
172    _LIBCPP_HIDE_FROM_ABI constexpr operator _PairMutable() const {
173      return __do_construct(std::forward<_Type>(this->__value_));
174    }
175  };
176
177  return std::make_tuple(__pair_constructor{__alloc, __value});
178}
179
180template <class _Type, class _Alloc, class... _Args>
181_LIBCPP_HIDE_FROM_ABI constexpr _Type __make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args) {
182  return std::make_from_tuple<_Type>(
183      std::__uses_allocator_construction_args<_Type>(__alloc, std::forward<_Args>(__args)...));
184}
185
186template <class _Type, class _Alloc, class... _Args>
187_LIBCPP_HIDE_FROM_ABI constexpr _Type*
188__uninitialized_construct_using_allocator(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args) {
189  return std::apply(
190      [&__ptr](auto&&... __xs) { return std::__construct_at(__ptr, std::forward<decltype(__xs)>(__xs)...); },
191      std::__uses_allocator_construction_args<_Type>(__alloc, std::forward<_Args>(__args)...));
192}
193
194#endif // _LIBCPP_STD_VER >= 17
195
196#if _LIBCPP_STD_VER >= 20
197
198template <class _Type, class _Alloc, class... _Args>
199_LIBCPP_HIDE_FROM_ABI constexpr auto uses_allocator_construction_args(const _Alloc& __alloc, _Args&&... __args) noexcept
200    -> decltype(std::__uses_allocator_construction_args<_Type>(__alloc, std::forward<_Args>(__args)...)) {
201  return /*--*/ std::__uses_allocator_construction_args<_Type>(__alloc, std::forward<_Args>(__args)...);
202}
203
204template <class _Type, class _Alloc, class... _Args>
205_LIBCPP_HIDE_FROM_ABI constexpr auto make_obj_using_allocator(const _Alloc& __alloc, _Args&&... __args)
206    -> decltype(std::__make_obj_using_allocator<_Type>(__alloc, std::forward<_Args>(__args)...)) {
207  return /*--*/ std::__make_obj_using_allocator<_Type>(__alloc, std::forward<_Args>(__args)...);
208}
209
210template <class _Type, class _Alloc, class... _Args>
211_LIBCPP_HIDE_FROM_ABI constexpr auto
212uninitialized_construct_using_allocator(_Type* __ptr, const _Alloc& __alloc, _Args&&... __args)
213    -> decltype(std::__uninitialized_construct_using_allocator(__ptr, __alloc, std::forward<_Args>(__args)...)) {
214  return /*--*/ std::__uninitialized_construct_using_allocator(__ptr, __alloc, std::forward<_Args>(__args)...);
215}
216
217#endif // _LIBCPP_STD_VER >= 20
218
219_LIBCPP_END_NAMESPACE_STD
220
221#endif // _LIBCPP___MEMORY_USES_ALLOCATOR_CONSTRUCTION_H
222