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#include <__config>
14#include <memory>
15#include <optional>
16
17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18#pragma GCC system_header
19#endif
20
21_LIBCPP_PUSH_MACROS
22#include <__undef_macros>
23
24_LIBCPP_BEGIN_NAMESPACE_STD
25
26#if _LIBCPP_STD_VER > 14
27
28// Specialized in __tree & __hash_table for their _NodeType.
29template <class _NodeType, class _Alloc>
30struct __generic_container_node_destructor;
31
32template <class _NodeType, class _Alloc,
33          template <class, class> class _MapOrSetSpecifics>
34class _LIBCPP_TEMPLATE_VIS __basic_node_handle
35    : public _MapOrSetSpecifics<
36          _NodeType,
37          __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>
38{
39    template <class _Tp, class _Compare, class _Allocator>
40        friend class __tree;
41    template <class _Tp, class _Hash, class _Equal, class _Allocator>
42        friend class __hash_table;
43    friend struct _MapOrSetSpecifics<
44        _NodeType, __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>;
45
46    typedef allocator_traits<_Alloc> __alloc_traits;
47    typedef typename __rebind_pointer<typename __alloc_traits::void_pointer,
48                                      _NodeType>::type
49        __node_pointer_type;
50
51public:
52    typedef _Alloc allocator_type;
53
54private:
55    __node_pointer_type __ptr_ = nullptr;
56    optional<allocator_type> __alloc_;
57
58    _LIBCPP_INLINE_VISIBILITY
59    void __release_ptr()
60    {
61        __ptr_ = nullptr;
62        __alloc_ = _VSTD::nullopt;
63    }
64
65    _LIBCPP_INLINE_VISIBILITY
66    void __destroy_node_pointer()
67    {
68        if (__ptr_ != nullptr)
69        {
70            typedef typename __allocator_traits_rebind<
71                allocator_type, _NodeType>::type __node_alloc_type;
72            __node_alloc_type __alloc(*__alloc_);
73            __generic_container_node_destructor<_NodeType, __node_alloc_type>(
74                __alloc, true)(__ptr_);
75            __ptr_ = nullptr;
76        }
77    }
78
79    _LIBCPP_INLINE_VISIBILITY
80    __basic_node_handle(__node_pointer_type __ptr,
81                        allocator_type const& __alloc)
82            : __ptr_(__ptr), __alloc_(__alloc)
83    {
84    }
85
86public:
87    _LIBCPP_INLINE_VISIBILITY
88    __basic_node_handle() = default;
89
90    _LIBCPP_INLINE_VISIBILITY
91    __basic_node_handle(__basic_node_handle&& __other) noexcept
92            : __ptr_(__other.__ptr_),
93              __alloc_(_VSTD::move(__other.__alloc_))
94    {
95        __other.__ptr_ = nullptr;
96        __other.__alloc_ = _VSTD::nullopt;
97    }
98
99    _LIBCPP_INLINE_VISIBILITY
100    __basic_node_handle& operator=(__basic_node_handle&& __other)
101    {
102        _LIBCPP_ASSERT(
103            __alloc_ == _VSTD::nullopt ||
104            __alloc_traits::propagate_on_container_move_assignment::value ||
105            __alloc_ == __other.__alloc_,
106            "node_type with incompatible allocator passed to "
107            "node_type::operator=(node_type&&)");
108
109        __destroy_node_pointer();
110        __ptr_ = __other.__ptr_;
111
112        if (__alloc_traits::propagate_on_container_move_assignment::value ||
113            __alloc_ == _VSTD::nullopt)
114            __alloc_ = _VSTD::move(__other.__alloc_);
115
116        __other.__ptr_ = nullptr;
117        __other.__alloc_ = _VSTD::nullopt;
118
119        return *this;
120    }
121
122    _LIBCPP_INLINE_VISIBILITY
123    allocator_type get_allocator() const { return *__alloc_; }
124
125    _LIBCPP_INLINE_VISIBILITY
126    explicit operator bool() const { return __ptr_ != nullptr; }
127
128    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
129    bool empty() const { return __ptr_ == nullptr; }
130
131    _LIBCPP_INLINE_VISIBILITY
132    void swap(__basic_node_handle& __other) noexcept(
133        __alloc_traits::propagate_on_container_swap::value ||
134        __alloc_traits::is_always_equal::value)
135    {
136        using _VSTD::swap;
137        swap(__ptr_, __other.__ptr_);
138        if (__alloc_traits::propagate_on_container_swap::value ||
139            __alloc_ == _VSTD::nullopt || __other.__alloc_ == _VSTD::nullopt)
140            swap(__alloc_, __other.__alloc_);
141    }
142
143    _LIBCPP_INLINE_VISIBILITY
144    friend void swap(__basic_node_handle& __a, __basic_node_handle& __b)
145        noexcept(noexcept(__a.swap(__b))) { __a.swap(__b); }
146
147    _LIBCPP_INLINE_VISIBILITY
148    ~__basic_node_handle()
149    {
150        __destroy_node_pointer();
151    }
152};
153
154template <class _NodeType, class _Derived>
155struct __set_node_handle_specifics
156{
157    typedef typename _NodeType::__node_value_type value_type;
158
159    _LIBCPP_INLINE_VISIBILITY
160    value_type& value() const
161    {
162        return static_cast<_Derived const*>(this)->__ptr_->__value_;
163    }
164};
165
166template <class _NodeType, class _Derived>
167struct __map_node_handle_specifics
168{
169    typedef typename _NodeType::__node_value_type::key_type key_type;
170    typedef typename _NodeType::__node_value_type::mapped_type mapped_type;
171
172    _LIBCPP_INLINE_VISIBILITY
173    key_type& key() const
174    {
175        return static_cast<_Derived const*>(this)->
176            __ptr_->__value_.__ref().first;
177    }
178
179    _LIBCPP_INLINE_VISIBILITY
180    mapped_type& mapped() const
181    {
182        return static_cast<_Derived const*>(this)->
183            __ptr_->__value_.__ref().second;
184    }
185};
186
187template <class _NodeType, class _Alloc>
188using __set_node_handle =
189    __basic_node_handle< _NodeType, _Alloc, __set_node_handle_specifics>;
190
191template <class _NodeType, class _Alloc>
192using __map_node_handle =
193    __basic_node_handle< _NodeType, _Alloc, __map_node_handle_specifics>;
194
195template <class _Iterator, class _NodeType>
196struct _LIBCPP_TEMPLATE_VIS __insert_return_type
197{
198    _Iterator position;
199    bool inserted;
200    _NodeType node;
201};
202
203#endif // _LIBCPP_STD_VER > 14
204
205_LIBCPP_END_NAMESPACE_STD
206_LIBCPP_POP_MACROS
207
208#endif
209