xref: /freebsd/contrib/llvm-project/libcxx/include/__node_handle (revision 86dc8398c9ca2283c5d6984992b7a585257b5adb)
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 <__debug>
15#include <memory>
16#include <optional>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#pragma GCC system_header
20#endif
21
22_LIBCPP_PUSH_MACROS
23#include <__undef_macros>
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27#if _LIBCPP_STD_VER > 14
28
29// Specialized in __tree & __hash_table for their _NodeType.
30template <class _NodeType, class _Alloc>
31struct __generic_container_node_destructor;
32
33template <class _NodeType, class _Alloc,
34          template <class, class> class _MapOrSetSpecifics>
35class _LIBCPP_TEMPLATE_VIS __basic_node_handle
36    : public _MapOrSetSpecifics<
37          _NodeType,
38          __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>
39{
40    template <class _Tp, class _Compare, class _Allocator>
41        friend class __tree;
42    template <class _Tp, class _Hash, class _Equal, class _Allocator>
43        friend class __hash_table;
44    friend struct _MapOrSetSpecifics<
45        _NodeType, __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>;
46
47    typedef allocator_traits<_Alloc> __alloc_traits;
48    typedef typename __rebind_pointer<typename __alloc_traits::void_pointer,
49                                      _NodeType>::type
50        __node_pointer_type;
51
52public:
53    typedef _Alloc allocator_type;
54
55private:
56    __node_pointer_type __ptr_ = nullptr;
57    optional<allocator_type> __alloc_;
58
59    _LIBCPP_INLINE_VISIBILITY
60    void __release_ptr()
61    {
62        __ptr_ = nullptr;
63        __alloc_ = _VSTD::nullopt;
64    }
65
66    _LIBCPP_INLINE_VISIBILITY
67    void __destroy_node_pointer()
68    {
69        if (__ptr_ != nullptr)
70        {
71            typedef typename __allocator_traits_rebind<
72                allocator_type, _NodeType>::type __node_alloc_type;
73            __node_alloc_type __alloc(*__alloc_);
74            __generic_container_node_destructor<_NodeType, __node_alloc_type>(
75                __alloc, true)(__ptr_);
76            __ptr_ = nullptr;
77        }
78    }
79
80    _LIBCPP_INLINE_VISIBILITY
81    __basic_node_handle(__node_pointer_type __ptr,
82                        allocator_type const& __alloc)
83            : __ptr_(__ptr), __alloc_(__alloc)
84    {
85    }
86
87public:
88    _LIBCPP_INLINE_VISIBILITY
89    __basic_node_handle() = default;
90
91    _LIBCPP_INLINE_VISIBILITY
92    __basic_node_handle(__basic_node_handle&& __other) noexcept
93            : __ptr_(__other.__ptr_),
94              __alloc_(_VSTD::move(__other.__alloc_))
95    {
96        __other.__ptr_ = nullptr;
97        __other.__alloc_ = _VSTD::nullopt;
98    }
99
100    _LIBCPP_INLINE_VISIBILITY
101    __basic_node_handle& operator=(__basic_node_handle&& __other)
102    {
103        _LIBCPP_ASSERT(
104            __alloc_ == _VSTD::nullopt ||
105            __alloc_traits::propagate_on_container_move_assignment::value ||
106            __alloc_ == __other.__alloc_,
107            "node_type with incompatible allocator passed to "
108            "node_type::operator=(node_type&&)");
109
110        __destroy_node_pointer();
111        __ptr_ = __other.__ptr_;
112
113        if (__alloc_traits::propagate_on_container_move_assignment::value ||
114            __alloc_ == _VSTD::nullopt)
115            __alloc_ = _VSTD::move(__other.__alloc_);
116
117        __other.__ptr_ = nullptr;
118        __other.__alloc_ = _VSTD::nullopt;
119
120        return *this;
121    }
122
123    _LIBCPP_INLINE_VISIBILITY
124    allocator_type get_allocator() const { return *__alloc_; }
125
126    _LIBCPP_INLINE_VISIBILITY
127    explicit operator bool() const { return __ptr_ != nullptr; }
128
129    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
130    bool empty() const { return __ptr_ == nullptr; }
131
132    _LIBCPP_INLINE_VISIBILITY
133    void swap(__basic_node_handle& __other) noexcept(
134        __alloc_traits::propagate_on_container_swap::value ||
135        __alloc_traits::is_always_equal::value)
136    {
137        using _VSTD::swap;
138        swap(__ptr_, __other.__ptr_);
139        if (__alloc_traits::propagate_on_container_swap::value ||
140            __alloc_ == _VSTD::nullopt || __other.__alloc_ == _VSTD::nullopt)
141            swap(__alloc_, __other.__alloc_);
142    }
143
144    _LIBCPP_INLINE_VISIBILITY
145    friend void swap(__basic_node_handle& __a, __basic_node_handle& __b)
146        noexcept(noexcept(__a.swap(__b))) { __a.swap(__b); }
147
148    _LIBCPP_INLINE_VISIBILITY
149    ~__basic_node_handle()
150    {
151        __destroy_node_pointer();
152    }
153};
154
155template <class _NodeType, class _Derived>
156struct __set_node_handle_specifics
157{
158    typedef typename _NodeType::__node_value_type value_type;
159
160    _LIBCPP_INLINE_VISIBILITY
161    value_type& value() const
162    {
163        return static_cast<_Derived const*>(this)->__ptr_->__value_;
164    }
165};
166
167template <class _NodeType, class _Derived>
168struct __map_node_handle_specifics
169{
170    typedef typename _NodeType::__node_value_type::key_type key_type;
171    typedef typename _NodeType::__node_value_type::mapped_type mapped_type;
172
173    _LIBCPP_INLINE_VISIBILITY
174    key_type& key() const
175    {
176        return static_cast<_Derived const*>(this)->
177            __ptr_->__value_.__ref().first;
178    }
179
180    _LIBCPP_INLINE_VISIBILITY
181    mapped_type& mapped() const
182    {
183        return static_cast<_Derived const*>(this)->
184            __ptr_->__value_.__ref().second;
185    }
186};
187
188template <class _NodeType, class _Alloc>
189using __set_node_handle =
190    __basic_node_handle< _NodeType, _Alloc, __set_node_handle_specifics>;
191
192template <class _NodeType, class _Alloc>
193using __map_node_handle =
194    __basic_node_handle< _NodeType, _Alloc, __map_node_handle_specifics>;
195
196template <class _Iterator, class _NodeType>
197struct _LIBCPP_TEMPLATE_VIS __insert_return_type
198{
199    _Iterator position;
200    bool inserted;
201    _NodeType node;
202};
203
204#endif // _LIBCPP_STD_VER > 14
205
206_LIBCPP_END_NAMESPACE_STD
207_LIBCPP_POP_MACROS
208
209#endif  // _LIBCPP___NODE_HANDLE
210