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_UTILITY
11#define _LIBCPP_UTILITY
12
13/*
14    utility synopsis
15
16#include <initializer_list>
17
18namespace std
19{
20
21template <class T>
22    void
23    swap(T& a, T& b);
24
25namespace rel_ops
26{
27    template<class T> bool operator!=(const T&, const T&);
28    template<class T> bool operator> (const T&, const T&);
29    template<class T> bool operator<=(const T&, const T&);
30    template<class T> bool operator>=(const T&, const T&);
31}
32
33template<class T>
34void
35swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
36                          is_nothrow_move_assignable<T>::value);
37
38template <class T, size_t N>
39void
40swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
41
42template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
43template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
44
45template <typename T>
46[[nodiscard]] constexpr
47auto forward_like(auto&& x) noexcept -> see below;                               // since C++23
48
49template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
50
51template <class T>
52    typename conditional
53    <
54        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
55        const T&,
56        T&&
57    >::type
58    move_if_noexcept(T& x) noexcept; // constexpr in C++14
59
60template <class T> constexpr add_const_t<T>& as_const(T& t) noexcept;      // C++17
61template <class T>                      void as_const(const T&&) = delete; // C++17
62
63template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
64
65template<class T, class U> constexpr bool cmp_equal(T t, U u) noexcept;         // C++20
66template<class T, class U> constexpr bool cmp_not_equal(T t, U u) noexcept;     // C++20
67template<class T, class U> constexpr bool cmp_less(T t, U u) noexcept;          // C++20
68template<class T, class U> constexpr bool cmp_greater(T t, U u) noexcept;       // C++20
69template<class T, class U> constexpr bool cmp_less_equal(T t, U u) noexcept;    // C++20
70template<class T, class U> constexpr bool cmp_greater_equal(T t, U u) noexcept; // C++20
71template<class R, class T> constexpr bool in_range(T t) noexcept;               // C++20
72
73template <class T1, class T2>
74struct pair
75{
76    typedef T1 first_type;
77    typedef T2 second_type;
78
79    T1 first;
80    T2 second;
81
82    pair(const pair&) = default;
83    pair(pair&&) = default;
84    explicit(see-below) constexpr pair();
85    explicit(see-below) pair(const T1& x, const T2& y);                          // constexpr in C++14
86    template <class U = T1, class V = T2> explicit(see-below) pair(U&&, V&&);    // constexpr in C++14
87    template <class U, class V> constexpr explicit(see-below) pair(pair<U, V>&); // since C++23
88    template <class U, class V> explicit(see-below) pair(const pair<U, V>& p);   // constexpr in C++14
89    template <class U, class V> explicit(see-below) pair(pair<U, V>&& p);        // constexpr in C++14
90    template <class U, class V>
91    constexpr explicit(see-below) pair(const pair<U, V>&&);                      // since C++23
92    template <pair-like P> constexpr explicit(see-below) pair(P&&);              // since C++23
93    template <class... Args1, class... Args2>
94        pair(piecewise_construct_t, tuple<Args1...> first_args,                  // constexpr in C++20
95                                    tuple<Args2...> second_args);
96
97    constexpr const pair& operator=(const pair& p) const;                        // since C++23
98    template <class U, class V> pair& operator=(const pair<U, V>& p);            // constexpr in C++20
99    template <class U, class V>
100    constexpr const pair& operator=(const pair<U, V>& p) const;                  // since C++23
101    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
102                                       is_nothrow_move_assignable<T2>::value);   // constexpr in C++20
103    constexpr const pair& operator=(pair&& p) const;                             // since C++23
104    template <class U, class V> pair& operator=(pair<U, V>&& p);                 // constexpr in C++20
105    template <class U, class V>
106    constexpr const pair& operator=(pair<U, V>&& p) const;                       // since C++23
107    template <pair-like P> constexpr pair& operator=(P&&);                       // since C++23
108    template <pair-like P> constexpr const pair& operator=(P&&) const;           // since C++23
109
110    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
111                                is_nothrow_swappable_v<T2>);                     // constexpr in C++20
112    constexpr void swap(const pair& p) const noexcept(see below);                // since C++23
113};
114
115template<class T1, class T2, class U1, class U2, template<class> class TQual, template<class> class UQual>
116struct basic_common_reference<pair<T1, T2>, pair<U1, U2>, TQual, UQual>;         // since C++23
117
118template<class T1, class T2, class U1, class U2>
119struct common_type<pair<T1, T2>, pair<U1, U2>>;                                  // since C++23
120
121template<class T1, class T2> pair(T1, T2) -> pair<T1, T2>;
122
123template <class T1, class T2, class U1, class U2>
124bool operator==(const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14
125template <class T1, class T2, class U1, class U2>
126bool operator!=(const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14, removed in C++20
127template <class T1, class T2, class U1, class U2>
128bool operator< (const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14, removed in C++20
129template <class T1, class T2, class U1, class U2>
130bool operator> (const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14, removed in C++20
131template <class T1, class T2, class U1, class U2>
132bool operator>=(const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14, removed in C++20
133template <class T1, class T2, class U1, class U2>
134bool operator<=(const pair<T1,T2>&, const pair<U1,U2>&);                         // constexpr in C++14, removed in C++20
135template <class T1, class T2, class U1, class U2>
136  constexpr common_comparison_type_t<synth-three-way-result<T1,U1>,
137                                     synth-three-way-result<T2,U2>>
138    operator<=>(const pair<T1,T2>&, const pair<U1,U2>&);                         // C++20
139
140template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);                // constexpr in C++14
141template <class T1, class T2>
142void
143swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));            // constexpr in C++20
144
145template<class T1, class T2>                                                     // since C++23
146constexpr void swap(const pair<T1, T2>& x, const pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
147
148struct piecewise_construct_t { explicit piecewise_construct_t() = default; };
149inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
150
151template <class T> struct tuple_size;
152template <size_t I, class T> struct tuple_element;
153
154template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
155template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
156template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
157
158template<size_t I, class T1, class T2>
159    typename tuple_element<I, pair<T1, T2> >::type&
160    get(pair<T1, T2>&) noexcept; // constexpr in C++14
161
162template<size_t I, class T1, class T2>
163    const typename tuple_element<I, pair<T1, T2> >::type&
164    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
165
166template<size_t I, class T1, class T2>
167    typename tuple_element<I, pair<T1, T2> >::type&&
168    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
169
170template<size_t I, class T1, class T2>
171    const typename tuple_element<I, pair<T1, T2> >::type&&
172    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
173
174template<class T1, class T2>
175    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
176
177template<class T1, class T2>
178    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
179
180template<class T1, class T2>
181    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
182
183template<class T1, class T2>
184    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
185
186template<class T1, class T2>
187    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
188
189template<class T1, class T2>
190    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
191
192template<class T1, class T2>
193    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
194
195template<class T1, class T2>
196    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
197
198// C++14
199
200template<class T, T... I>
201struct integer_sequence
202{
203    typedef T value_type;
204
205    static constexpr size_t size() noexcept;
206};
207
208template<size_t... I>
209  using index_sequence = integer_sequence<size_t, I...>;
210
211template<class T, T N>
212  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
213template<size_t N>
214  using make_index_sequence = make_integer_sequence<size_t, N>;
215
216template<class... T>
217  using index_sequence_for = make_index_sequence<sizeof...(T)>;
218
219template<class T, class U=T>
220    constexpr T exchange(T& obj, U&& new_value)                                 // constexpr in C++17, noexcept in C++23
221      noexcept(is_nothrow_move_constructible<T>::value && is_nothrow_assignable<T&, U>::value);
222
223// 20.2.7, in-place construction // C++17
224struct in_place_t {
225  explicit in_place_t() = default;
226};
227inline constexpr in_place_t in_place{};
228template <class T>
229  struct in_place_type_t {
230    explicit in_place_type_t() = default;
231  };
232template <class T>
233  inline constexpr in_place_type_t<T> in_place_type{};
234template <size_t I>
235  struct in_place_index_t {
236    explicit in_place_index_t() = default;
237  };
238template <size_t I>
239  inline constexpr in_place_index_t<I> in_place_index{};
240
241// [utility.underlying], to_underlying
242template <class T>
243    constexpr underlying_type_t<T> to_underlying( T value ) noexcept; // C++23
244
245}  // std
246
247*/
248
249#include <__assert> // all public C++ headers provide the assertion handler
250#include <__config>
251#include <__utility/as_const.h>
252#include <__utility/auto_cast.h>
253#include <__utility/cmp.h>
254#include <__utility/declval.h>
255#include <__utility/exception_guard.h>
256#include <__utility/exchange.h>
257#include <__utility/forward.h>
258#include <__utility/forward_like.h>
259#include <__utility/in_place.h>
260#include <__utility/integer_sequence.h>
261#include <__utility/move.h>
262#include <__utility/pair.h>
263#include <__utility/piecewise_construct.h>
264#include <__utility/priority_tag.h>
265#include <__utility/rel_ops.h>
266#include <__utility/swap.h>
267#include <__utility/to_underlying.h>
268#include <__utility/unreachable.h>
269#include <version>
270
271// standard-mandated includes
272
273// [utility.syn]
274#include <compare>
275#include <initializer_list>
276
277// [tuple.helper]
278#include <__tuple/tuple_element.h>
279#include <__tuple/tuple_size.h>
280
281#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
282#  pragma GCC system_header
283#endif
284
285#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
286#  include <cstdlib>
287#  include <iosfwd>
288#  include <type_traits>
289#endif
290
291#endif // _LIBCPP_UTILITY
292