master
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___NODE_HANDLE
11#define _LIBCPP___NODE_HANDLE
12
13/*
14
15template<unspecified>
16class node-handle {
17public:
18 using value_type = see below; // not present for map containers
19 using key_type = see below; // not present for set containers
20 using mapped_type = see below; // not present for set containers
21 using allocator_type = see below;
22
23private:
24 using container_node_type = unspecified; // exposition only
25 using ator_traits = allocator_traits<allocator_type>; // exposition only
26
27 typename ator_traits::template
28 rebind_traits<container_node_type>::pointer ptr_; // exposition only
29 optional<allocator_type> alloc_; // exposition only
30
31public:
32 // [container.node.cons], constructors, copy, and assignment
33 constexpr node-handle() noexcept : ptr_(), alloc_() {}
34 node-handle(node-handle&&) noexcept;
35 node-handle& operator=(node-handle&&);
36
37 // [container.node.dtor], destructor
38 ~node-handle();
39
40 // [container.node.observers], observers
41 value_type& value() const; // not present for map containers
42 key_type& key() const; // not present for set containers
43 mapped_type& mapped() const; // not present for set containers
44
45 allocator_type get_allocator() const;
46 explicit operator bool() const noexcept;
47 [[nodiscard]] bool empty() const noexcept; // nodiscard since C++20
48
49 // [container.node.modifiers], modifiers
50 void swap(node-handle&)
51 noexcept(ator_traits::propagate_on_container_swap::value ||
52 ator_traits::is_always_equal::value);
53
54 friend void swap(node-handle& x, node-handle& y) noexcept(noexcept(x.swap(y))) {
55 x.swap(y);
56 }
57};
58
59*/
60
61#include <__assert>
62#include <__config>
63#include <__memory/allocator_traits.h>
64#include <__memory/pointer_traits.h>
65#include <__type_traits/is_specialization.h>
66#include <optional>
67
68#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
69# pragma GCC system_header
70#endif
71
72_LIBCPP_PUSH_MACROS
73#include <__undef_macros>
74
75_LIBCPP_BEGIN_NAMESPACE_STD
76
77#if _LIBCPP_STD_VER >= 17
78
79// Specialized in __tree & __hash_table for their _NodeType.
80template <class _NodeType, class _Alloc>
81struct __generic_container_node_destructor;
82
83template <class _NodeType, class _Alloc, template <class, class> class _MapOrSetSpecifics>
84class __basic_node_handle
85 : public _MapOrSetSpecifics< _NodeType, __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>> {
86 template <class _Tp, class _Compare, class _Allocator>
87 friend class __tree;
88 template <class _Tp, class _Hash, class _Equal, class _Allocator>
89 friend class __hash_table;
90 friend struct _MapOrSetSpecifics< _NodeType, __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>;
91
92 typedef allocator_traits<_Alloc> __alloc_traits;
93 typedef __rebind_pointer_t<typename __alloc_traits::void_pointer, _NodeType> __node_pointer_type;
94
95public:
96 typedef _Alloc allocator_type;
97
98private:
99 __node_pointer_type __ptr_ = nullptr;
100 optional<allocator_type> __alloc_;
101
102 _LIBCPP_HIDE_FROM_ABI void __release_ptr() {
103 __ptr_ = nullptr;
104 __alloc_ = std::nullopt;
105 }
106
107 _LIBCPP_HIDE_FROM_ABI void __destroy_node_pointer() {
108 if (__ptr_ != nullptr) {
109 typedef typename __allocator_traits_rebind< allocator_type, _NodeType>::type __node_alloc_type;
110 __node_alloc_type __alloc(*__alloc_);
111 __generic_container_node_destructor<_NodeType, __node_alloc_type>(__alloc, true)(__ptr_);
112 __ptr_ = nullptr;
113 }
114 }
115
116 _LIBCPP_HIDE_FROM_ABI __basic_node_handle(__node_pointer_type __ptr, allocator_type const& __alloc)
117 : __ptr_(__ptr), __alloc_(__alloc) {}
118
119public:
120 _LIBCPP_HIDE_FROM_ABI __basic_node_handle() = default;
121
122 _LIBCPP_HIDE_FROM_ABI __basic_node_handle(__basic_node_handle&& __other) noexcept
123 : __ptr_(__other.__ptr_), __alloc_(std::move(__other.__alloc_)) {
124 __other.__ptr_ = nullptr;
125 __other.__alloc_ = std::nullopt;
126 }
127
128 _LIBCPP_HIDE_FROM_ABI __basic_node_handle& operator=(__basic_node_handle&& __other) {
129 _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
130 __alloc_ == std::nullopt || __alloc_traits::propagate_on_container_move_assignment::value ||
131 __alloc_ == __other.__alloc_,
132 "node_type with incompatible allocator passed to "
133 "node_type::operator=(node_type&&)");
134
135 __destroy_node_pointer();
136 __ptr_ = __other.__ptr_;
137
138 if (__alloc_traits::propagate_on_container_move_assignment::value || __alloc_ == std::nullopt)
139 __alloc_ = std::move(__other.__alloc_);
140
141 __other.__ptr_ = nullptr;
142 __other.__alloc_ = std::nullopt;
143
144 return *this;
145 }
146
147 _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const { return *__alloc_; }
148
149 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const { return __ptr_ != nullptr; }
150
151 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool empty() const { return __ptr_ == nullptr; }
152
153 _LIBCPP_HIDE_FROM_ABI void swap(__basic_node_handle& __other) noexcept(
154 __alloc_traits::propagate_on_container_swap::value || __alloc_traits::is_always_equal::value) {
155 using std::swap;
156 swap(__ptr_, __other.__ptr_);
157 if (__alloc_traits::propagate_on_container_swap::value || __alloc_ == std::nullopt ||
158 __other.__alloc_ == std::nullopt)
159 swap(__alloc_, __other.__alloc_);
160 }
161
162 _LIBCPP_HIDE_FROM_ABI friend void
163 swap(__basic_node_handle& __a, __basic_node_handle& __b) noexcept(noexcept(__a.swap(__b))) {
164 __a.swap(__b);
165 }
166
167 _LIBCPP_HIDE_FROM_ABI ~__basic_node_handle() { __destroy_node_pointer(); }
168};
169
170template <class _NodeType, class _Derived>
171struct __set_node_handle_specifics {
172 typedef typename _NodeType::__node_value_type value_type;
173
174 _LIBCPP_HIDE_FROM_ABI value_type& value() const { return static_cast<_Derived const*>(this)->__ptr_->__get_value(); }
175};
176
177template <class _NodeType, class _Derived>
178struct __map_node_handle_specifics {
179 using key_type = __remove_const_t<typename _NodeType::__node_value_type::first_type>;
180 using mapped_type = typename _NodeType::__node_value_type::second_type;
181
182 _LIBCPP_HIDE_FROM_ABI key_type& key() const {
183 return const_cast<key_type&>(static_cast<_Derived const*>(this)->__ptr_->__get_value().first);
184 }
185
186 _LIBCPP_HIDE_FROM_ABI mapped_type& mapped() const {
187 return static_cast<_Derived const*>(this)->__ptr_->__get_value().second;
188 }
189};
190
191template <class _NodeType, class _Alloc>
192using __set_node_handle _LIBCPP_NODEBUG = __basic_node_handle< _NodeType, _Alloc, __set_node_handle_specifics>;
193
194template <class _NodeType, class _Alloc>
195using __map_node_handle _LIBCPP_NODEBUG = __basic_node_handle< _NodeType, _Alloc, __map_node_handle_specifics>;
196
197template <class _Iterator, class _NodeType>
198struct __insert_return_type {
199 _Iterator position;
200 bool inserted;
201 _NodeType node;
202};
203
204#endif // _LIBCPP_STD_VER >= 17
205
206_LIBCPP_END_NAMESPACE_STD
207
208_LIBCPP_POP_MACROS
209
210#endif // _LIBCPP___NODE_HANDLE