xref: /llvm-project-15.0.7/libcxx/include/array (revision 2e2f3158)
13e519524SHoward Hinnant// -*- C++ -*-
2eb8650a7SLouis Dionne//===----------------------------------------------------------------------===//
33e519524SHoward Hinnant//
457b08b09SChandler Carruth// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
557b08b09SChandler Carruth// See https://llvm.org/LICENSE.txt for license information.
657b08b09SChandler Carruth// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
73e519524SHoward Hinnant//
83e519524SHoward Hinnant//===----------------------------------------------------------------------===//
93e519524SHoward Hinnant
103e519524SHoward Hinnant#ifndef _LIBCPP_ARRAY
113e519524SHoward Hinnant#define _LIBCPP_ARRAY
123e519524SHoward Hinnant
133e519524SHoward Hinnant/*
143e519524SHoward Hinnant    array synopsis
153e519524SHoward Hinnant
163e519524SHoward Hinnantnamespace std
173e519524SHoward Hinnant{
183e519524SHoward Hinnanttemplate <class T, size_t N >
193e519524SHoward Hinnantstruct array
203e519524SHoward Hinnant{
213e519524SHoward Hinnant    // types:
223e519524SHoward Hinnant    typedef T & reference;
233e519524SHoward Hinnant    typedef const T & const_reference;
243e519524SHoward Hinnant    typedef implementation defined iterator;
253e519524SHoward Hinnant    typedef implementation defined const_iterator;
263e519524SHoward Hinnant    typedef size_t size_type;
273e519524SHoward Hinnant    typedef ptrdiff_t difference_type;
283e519524SHoward Hinnant    typedef T value_type;
293e519524SHoward Hinnant    typedef T* pointer;
303e519524SHoward Hinnant    typedef const T* const_pointer;
313e519524SHoward Hinnant    typedef std::reverse_iterator<iterator> reverse_iterator;
323e519524SHoward Hinnant    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
333e519524SHoward Hinnant
343e519524SHoward Hinnant    // No explicit construct/copy/destroy for aggregate type
3577b9abfcSLouis Dionne    void fill(const T& u);                                      // constexpr in C++20
3677b9abfcSLouis Dionne    void swap(array& a) noexcept(is_nothrow_swappable_v<T>);    // constexpr in C++20
373e519524SHoward Hinnant
383e519524SHoward Hinnant    // iterators:
3977b9abfcSLouis Dionne    iterator begin() noexcept;                                  // constexpr in C++17
4077b9abfcSLouis Dionne    const_iterator begin() const noexcept;                      // constexpr in C++17
4177b9abfcSLouis Dionne    iterator end() noexcept;                                    // constexpr in C++17
4277b9abfcSLouis Dionne    const_iterator end() const noexcept;                        // constexpr in C++17
433e519524SHoward Hinnant
4477b9abfcSLouis Dionne    reverse_iterator rbegin() noexcept;                         // constexpr in C++17
4577b9abfcSLouis Dionne    const_reverse_iterator rbegin() const noexcept;             // constexpr in C++17
4677b9abfcSLouis Dionne    reverse_iterator rend() noexcept;                           // constexpr in C++17
4777b9abfcSLouis Dionne    const_reverse_iterator rend() const noexcept;               // constexpr in C++17
483e519524SHoward Hinnant
4977b9abfcSLouis Dionne    const_iterator cbegin() const noexcept;                     // constexpr in C++17
5077b9abfcSLouis Dionne    const_iterator cend() const noexcept;                       // constexpr in C++17
5177b9abfcSLouis Dionne    const_reverse_iterator crbegin() const noexcept;            // constexpr in C++17
5277b9abfcSLouis Dionne    const_reverse_iterator crend() const noexcept;              // constexpr in C++17
533e519524SHoward Hinnant
543e519524SHoward Hinnant    // capacity:
558f0cd597SHoward Hinnant    constexpr size_type size() const noexcept;
568f0cd597SHoward Hinnant    constexpr size_type max_size() const noexcept;
57397717b7SHoward Hinnant    constexpr bool empty() const noexcept;
583e519524SHoward Hinnant
593e519524SHoward Hinnant    // element access:
6077b9abfcSLouis Dionne    reference operator[](size_type n);                          // constexpr in C++17
618bf1f08aSMarshall Clow    const_reference operator[](size_type n) const;              // constexpr in C++14
6277b9abfcSLouis Dionne    reference at(size_type n);                                  // constexpr in C++17
638bf1f08aSMarshall Clow    const_reference at(size_type n) const;                      // constexpr in C++14
643e519524SHoward Hinnant
6577b9abfcSLouis Dionne    reference front();                                          // constexpr in C++17
668bf1f08aSMarshall Clow    const_reference front() const;                              // constexpr in C++14
6777b9abfcSLouis Dionne    reference back();                                           // constexpr in C++17
688bf1f08aSMarshall Clow    const_reference back() const;                               // constexpr in C++14
693e519524SHoward Hinnant
7077b9abfcSLouis Dionne    T* data() noexcept;                                         // constexpr in C++17
7177b9abfcSLouis Dionne    const T* data() const noexcept;                             // constexpr in C++17
723e519524SHoward Hinnant};
733e519524SHoward Hinnant
740ca8c089SMarshall Clowtemplate <class T, class... U>
7577b9abfcSLouis Dionne  array(T, U...) -> array<T, 1 + sizeof...(U)>;                 // C++17
760ca8c089SMarshall Clow
773e519524SHoward Hinnanttemplate <class T, size_t N>
7877b9abfcSLouis Dionne  bool operator==(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
793e519524SHoward Hinnanttemplate <class T, size_t N>
8077b9abfcSLouis Dionne  bool operator!=(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
813e519524SHoward Hinnanttemplate <class T, size_t N>
8277b9abfcSLouis Dionne  bool operator<(const array<T,N>& x, const array<T,N>& y);     // constexpr in C++20
833e519524SHoward Hinnanttemplate <class T, size_t N>
8477b9abfcSLouis Dionne  bool operator>(const array<T,N>& x, const array<T,N>& y);     // constexpr in C++20
853e519524SHoward Hinnanttemplate <class T, size_t N>
8677b9abfcSLouis Dionne  bool operator<=(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
873e519524SHoward Hinnanttemplate <class T, size_t N>
8877b9abfcSLouis Dionne  bool operator>=(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
893e519524SHoward Hinnant
903e519524SHoward Hinnanttemplate <class T, size_t N >
9177b9abfcSLouis Dionne  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // constexpr in C++20
9277b9abfcSLouis Dionne
9377b9abfcSLouis Dionnetemplate <class T, size_t N>
9477b9abfcSLouis Dionne  constexpr array<remove_cv_t<T>, N> to_array(T (&a)[N]);  // C++20
9577b9abfcSLouis Dionnetemplate <class T, size_t N>
9677b9abfcSLouis Dionne  constexpr array<remove_cv_t<T>, N> to_array(T (&&a)[N]); // C++20
973e519524SHoward Hinnant
98e4957601SMarshall Clowtemplate <class T> struct tuple_size;
992b0c7abbSLouis Dionnetemplate <size_t I, class T> struct tuple_element;
1003e519524SHoward Hinnanttemplate <class T, size_t N> struct tuple_size<array<T, N>>;
1015fcc8169SMarshall Clowtemplate <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
1025fcc8169SMarshall Clowtemplate <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept;               // constexpr in C++14
1035fcc8169SMarshall Clowtemplate <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept;   // constexpr in C++14
1045fcc8169SMarshall Clowtemplate <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept;             // constexpr in C++14
105545b8861SEric Fiseliertemplate <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
1063e519524SHoward Hinnant
1073e519524SHoward Hinnant}  // std
1083e519524SHoward Hinnant
1093e519524SHoward Hinnant*/
1103e519524SHoward Hinnant
111*2e2f3158SNikolas Klauser#include <__algorithm/equal.h>
112*2e2f3158SNikolas Klauser#include <__algorithm/fill_n.h>
113*2e2f3158SNikolas Klauser#include <__algorithm/lexicographical_compare.h>
114*2e2f3158SNikolas Klauser#include <__algorithm/swap_ranges.h>
1153e519524SHoward Hinnant#include <__config>
116bfbd73f8SArthur O'Dwyer#include <__debug>
1173e519524SHoward Hinnant#include <__tuple>
1182a8f9a5eSNikolas Klauser#include <__utility/unreachable.h>
119bfbd73f8SArthur O'Dwyer#include <iterator>
120bfbd73f8SArthur O'Dwyer#include <stdexcept>
1213e519524SHoward Hinnant#include <type_traits>
1223e519524SHoward Hinnant#include <utility>
123f56972e2SMarshall Clow#include <version>
1243e519524SHoward Hinnant
125073458b1SHoward Hinnant#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1263e519524SHoward Hinnant#  pragma GCC system_header
127073458b1SHoward Hinnant#endif
1283e519524SHoward Hinnant
1293e519524SHoward Hinnant_LIBCPP_BEGIN_NAMESPACE_STD
1303e519524SHoward Hinnant
1313e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
132e2f2d1edSEric Fiselierstruct _LIBCPP_TEMPLATE_VIS array
1333e519524SHoward Hinnant{
1343e519524SHoward Hinnant    // types:
1353e519524SHoward Hinnant    typedef array __self;
1363e519524SHoward Hinnant    typedef _Tp                                   value_type;
1373e519524SHoward Hinnant    typedef value_type&                           reference;
1383e519524SHoward Hinnant    typedef const value_type&                     const_reference;
1393e519524SHoward Hinnant    typedef value_type*                           iterator;
1403e519524SHoward Hinnant    typedef const value_type*                     const_iterator;
1413e519524SHoward Hinnant    typedef value_type*                           pointer;
1423e519524SHoward Hinnant    typedef const value_type*                     const_pointer;
1433e519524SHoward Hinnant    typedef size_t                                size_type;
1443e519524SHoward Hinnant    typedef ptrdiff_t                             difference_type;
145d586f92cSArthur O'Dwyer    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
146d586f92cSArthur O'Dwyer    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
1473e519524SHoward Hinnant
14859cdf90aSEric Fiselier    _Tp __elems_[_Size];
1493e519524SHoward Hinnant
1503e519524SHoward Hinnant    // No explicit construct/copy/destroy for aggregate type
15177b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15277b9abfcSLouis Dionne    void fill(const value_type& __u) {
15366a14d15SLouis Dionne        _VSTD::fill_n(data(), _Size, __u);
15459cdf90aSEric Fiselier    }
155afeda5c2SEric Fiselier
15677b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
15759cdf90aSEric Fiselier    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
158d586f92cSArthur O'Dwyer        _VSTD::swap_ranges(data(), data() + _Size, __a.data());
15959cdf90aSEric Fiselier    }
1603e519524SHoward Hinnant
1613e519524SHoward Hinnant    // iterators:
162020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
16359cdf90aSEric Fiselier    iterator begin() _NOEXCEPT {return iterator(data());}
164020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
16559cdf90aSEric Fiselier    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
166020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
16759cdf90aSEric Fiselier    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
168020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
16959cdf90aSEric Fiselier    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
1703e519524SHoward Hinnant
171020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1728f0cd597SHoward Hinnant    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
173020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1748f0cd597SHoward Hinnant    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
175020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1768f0cd597SHoward Hinnant    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
177020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1788f0cd597SHoward Hinnant    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
1793e519524SHoward Hinnant
180020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1818f0cd597SHoward Hinnant    const_iterator cbegin() const _NOEXCEPT {return begin();}
182020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1838f0cd597SHoward Hinnant    const_iterator cend() const _NOEXCEPT {return end();}
184020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1858f0cd597SHoward Hinnant    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
186020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1878f0cd597SHoward Hinnant    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
1883e519524SHoward Hinnant
1893e519524SHoward Hinnant    // capacity:
1908f0cd597SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
191397717b7SHoward Hinnant    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
1928f0cd597SHoward Hinnant    _LIBCPP_INLINE_VISIBILITY
193397717b7SHoward Hinnant    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
19472c8fad4SMarshall Clow    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
19566a14d15SLouis Dionne    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
1963e519524SHoward Hinnant
1973e519524SHoward Hinnant    // element access:
198e7826950SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
19923776a17SLouis Dionne    reference operator[](size_type __n) _NOEXCEPT {
20023776a17SLouis Dionne        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
20123776a17SLouis Dionne        return __elems_[__n];
20223776a17SLouis Dionne    }
203e7826950SMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
20423776a17SLouis Dionne    const_reference operator[](size_type __n) const _NOEXCEPT {
20523776a17SLouis Dionne        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
20623776a17SLouis Dionne        return __elems_[__n];
20723776a17SLouis Dionne    }
208e7826950SMarshall Clow
2090161874cSLouis Dionne    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
2100161874cSLouis Dionne    {
2110161874cSLouis Dionne        if (__n >= _Size)
2120161874cSLouis Dionne            __throw_out_of_range("array::at");
2130161874cSLouis Dionne        return __elems_[__n];
2140161874cSLouis Dionne    }
2150161874cSLouis Dionne
2160161874cSLouis Dionne    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
2170161874cSLouis Dionne    {
2180161874cSLouis Dionne        if (__n >= _Size)
2190161874cSLouis Dionne            __throw_out_of_range("array::at");
2200161874cSLouis Dionne        return __elems_[__n];
2210161874cSLouis Dionne    }
2223e519524SHoward Hinnant
22323776a17SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return (*this)[0];}
22423776a17SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return (*this)[0];}
22523776a17SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
22623776a17SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
2273e519524SHoward Hinnant
228020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
229936ff584SNirav Dave    value_type* data() _NOEXCEPT {return __elems_;}
230020b623aSMarshall Clow    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
231936ff584SNirav Dave    const value_type* data() const _NOEXCEPT {return __elems_;}
2323e519524SHoward Hinnant};
2333e519524SHoward Hinnant
23459cdf90aSEric Fiseliertemplate <class _Tp>
23559cdf90aSEric Fiselierstruct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
23659cdf90aSEric Fiselier{
23759cdf90aSEric Fiselier    // types:
23859cdf90aSEric Fiselier    typedef array __self;
23959cdf90aSEric Fiselier    typedef _Tp                                   value_type;
24059cdf90aSEric Fiselier    typedef value_type&                           reference;
24159cdf90aSEric Fiselier    typedef const value_type&                     const_reference;
24259cdf90aSEric Fiselier    typedef value_type*                           iterator;
24359cdf90aSEric Fiselier    typedef const value_type*                     const_iterator;
24459cdf90aSEric Fiselier    typedef value_type*                           pointer;
24559cdf90aSEric Fiselier    typedef const value_type*                     const_pointer;
24659cdf90aSEric Fiselier    typedef size_t                                size_type;
24759cdf90aSEric Fiselier    typedef ptrdiff_t                             difference_type;
248d586f92cSArthur O'Dwyer    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
249d586f92cSArthur O'Dwyer    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
25059cdf90aSEric Fiselier
25159cdf90aSEric Fiselier    typedef typename conditional<is_const<_Tp>::value, const char,
25259cdf90aSEric Fiselier                                char>::type _CharType;
2531a78ae3cSEric Fiselier
2541a78ae3cSEric Fiselier    struct  _ArrayInStructT { _Tp __data_[1]; };
2551a78ae3cSEric Fiselier    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
25659cdf90aSEric Fiselier
2577265ff92SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2587265ff92SLouis Dionne    value_type* data() _NOEXCEPT {return nullptr;}
2597265ff92SLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2607265ff92SLouis Dionne    const value_type* data() const _NOEXCEPT {return nullptr;}
26177b9abfcSLouis Dionne
26259cdf90aSEric Fiselier    // No explicit construct/copy/destroy for aggregate type
26377b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
26477b9abfcSLouis Dionne    void fill(const value_type&) {
26559cdf90aSEric Fiselier      static_assert(!is_const<_Tp>::value,
26659cdf90aSEric Fiselier                    "cannot fill zero-sized array of type 'const T'");
26759cdf90aSEric Fiselier    }
26859cdf90aSEric Fiselier
26977b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
27059cdf90aSEric Fiselier    void swap(array&) _NOEXCEPT {
27159cdf90aSEric Fiselier      static_assert(!is_const<_Tp>::value,
27259cdf90aSEric Fiselier                    "cannot swap zero-sized array of type 'const T'");
27359cdf90aSEric Fiselier    }
27459cdf90aSEric Fiselier
27559cdf90aSEric Fiselier    // iterators:
27677b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
27759cdf90aSEric Fiselier    iterator begin() _NOEXCEPT {return iterator(data());}
27877b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
27959cdf90aSEric Fiselier    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
28077b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
28159cdf90aSEric Fiselier    iterator end() _NOEXCEPT {return iterator(data());}
28277b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
28359cdf90aSEric Fiselier    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
28459cdf90aSEric Fiselier
28577b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
28659cdf90aSEric Fiselier    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
28777b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
28859cdf90aSEric Fiselier    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
28977b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
29059cdf90aSEric Fiselier    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
29177b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
29259cdf90aSEric Fiselier    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
29359cdf90aSEric Fiselier
29477b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
29559cdf90aSEric Fiselier    const_iterator cbegin() const _NOEXCEPT {return begin();}
29677b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
29759cdf90aSEric Fiselier    const_iterator cend() const _NOEXCEPT {return end();}
29877b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
29959cdf90aSEric Fiselier    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
30077b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
30159cdf90aSEric Fiselier    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
30259cdf90aSEric Fiselier
30359cdf90aSEric Fiselier    // capacity:
30459cdf90aSEric Fiselier    _LIBCPP_INLINE_VISIBILITY
30559cdf90aSEric Fiselier    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
30659cdf90aSEric Fiselier    _LIBCPP_INLINE_VISIBILITY
30759cdf90aSEric Fiselier    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
30859cdf90aSEric Fiselier    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
30959cdf90aSEric Fiselier    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
31059cdf90aSEric Fiselier
31159cdf90aSEric Fiselier    // element access:
31277b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
3135f6a5ac1SMarshall Clow    reference operator[](size_type) _NOEXCEPT {
31459cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
3152a8f9a5eSNikolas Klauser      __libcpp_unreachable();
31659cdf90aSEric Fiselier    }
31759cdf90aSEric Fiselier
31859cdf90aSEric Fiselier    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
3195f6a5ac1SMarshall Clow    const_reference operator[](size_type) const _NOEXCEPT {
32059cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
3212a8f9a5eSNikolas Klauser      __libcpp_unreachable();
32259cdf90aSEric Fiselier    }
32359cdf90aSEric Fiselier
32477b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
32559cdf90aSEric Fiselier    reference at(size_type) {
32659cdf90aSEric Fiselier      __throw_out_of_range("array<T, 0>::at");
3272a8f9a5eSNikolas Klauser      __libcpp_unreachable();
32859cdf90aSEric Fiselier    }
32959cdf90aSEric Fiselier
33077b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
33159cdf90aSEric Fiselier    const_reference at(size_type) const {
33259cdf90aSEric Fiselier      __throw_out_of_range("array<T, 0>::at");
3332a8f9a5eSNikolas Klauser      __libcpp_unreachable();
33459cdf90aSEric Fiselier    }
33559cdf90aSEric Fiselier
33677b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
3379ea0e473SMarshall Clow    reference front() _NOEXCEPT {
33859cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
3392a8f9a5eSNikolas Klauser      __libcpp_unreachable();
34059cdf90aSEric Fiselier    }
34159cdf90aSEric Fiselier
34277b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
3439ea0e473SMarshall Clow    const_reference front() const _NOEXCEPT {
34459cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
3452a8f9a5eSNikolas Klauser      __libcpp_unreachable();
34659cdf90aSEric Fiselier    }
34759cdf90aSEric Fiselier
34877b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
3499ea0e473SMarshall Clow    reference back() _NOEXCEPT {
35059cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
3512a8f9a5eSNikolas Klauser      __libcpp_unreachable();
35259cdf90aSEric Fiselier    }
35359cdf90aSEric Fiselier
35477b9abfcSLouis Dionne    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
3559ea0e473SMarshall Clow    const_reference back() const _NOEXCEPT {
35659cdf90aSEric Fiselier      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
3572a8f9a5eSNikolas Klauser      __libcpp_unreachable();
35859cdf90aSEric Fiselier    }
35959cdf90aSEric Fiselier};
36059cdf90aSEric Fiselier
36159cdf90aSEric Fiselier
3622a8f9a5eSNikolas Klauser#if _LIBCPP_STD_VER > 14
3630ca8c089SMarshall Clowtemplate<class _Tp, class... _Args,
3644e0ea2cfSLouis Dionne         class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value>
3650ca8c089SMarshall Clow         >
3660ca8c089SMarshall Clowarray(_Tp, _Args...)
3670ca8c089SMarshall Clow  -> array<_Tp, 1 + sizeof...(_Args)>;
3680ca8c089SMarshall Clow#endif
3690ca8c089SMarshall Clow
3703e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
3713af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
37207d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
3733e519524SHoward Hinnantoperator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
3743e519524SHoward Hinnant{
37559cdf90aSEric Fiselier    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
3763e519524SHoward Hinnant}
3773e519524SHoward Hinnant
3783e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
3793af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
38007d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
3813e519524SHoward Hinnantoperator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
3823e519524SHoward Hinnant{
3833e519524SHoward Hinnant    return !(__x == __y);
3843e519524SHoward Hinnant}
3853e519524SHoward Hinnant
3863e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
3873af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
38807d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
3893e519524SHoward Hinnantoperator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
3903e519524SHoward Hinnant{
39159cdf90aSEric Fiselier    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
39259cdf90aSEric Fiselier                                          __y.begin(), __y.end());
3933e519524SHoward Hinnant}
3943e519524SHoward Hinnant
3953e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
3963af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
39707d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
3983e519524SHoward Hinnantoperator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
3993e519524SHoward Hinnant{
4003e519524SHoward Hinnant    return __y < __x;
4013e519524SHoward Hinnant}
4023e519524SHoward Hinnant
4033e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
4043af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
40507d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
4063e519524SHoward Hinnantoperator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
4073e519524SHoward Hinnant{
4083e519524SHoward Hinnant    return !(__y < __x);
4093e519524SHoward Hinnant}
4103e519524SHoward Hinnant
4113e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
4123af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY
41307d8ac0aSMarshall Clow_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
4143e519524SHoward Hinnantoperator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
4153e519524SHoward Hinnant{
4163e519524SHoward Hinnant    return !(__x < __y);
4173e519524SHoward Hinnant}
4183e519524SHoward Hinnant
4193e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
42077b9abfcSLouis Dionneinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
421bc95cf0dSHoward Hinnanttypename enable_if
422bc95cf0dSHoward Hinnant<
423f07dd8d0SEric Fiselier    _Size == 0 ||
424bc95cf0dSHoward Hinnant    __is_swappable<_Tp>::value,
4253e519524SHoward Hinnant    void
426bc95cf0dSHoward Hinnant>::type
427ee66eb13SMarshall Clowswap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
428f07dd8d0SEric Fiselier                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
4293e519524SHoward Hinnant{
4303e519524SHoward Hinnant    __x.swap(__y);
4313e519524SHoward Hinnant}
4323e519524SHoward Hinnant
4333e519524SHoward Hinnanttemplate <class _Tp, size_t _Size>
434e4957601SMarshall Clowstruct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
435f5ab703fSHoward Hinnant    : public integral_constant<size_t, _Size> {};
4363e519524SHoward Hinnant
4373e519524SHoward Hinnanttemplate <size_t _Ip, class _Tp, size_t _Size>
4382b0c7abbSLouis Dionnestruct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
4393e519524SHoward Hinnant{
4406db379a2SMarshall Clow    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
4413e519524SHoward Hinnant    typedef _Tp type;
4423e519524SHoward Hinnant};
4433e519524SHoward Hinnant
4443e519524SHoward Hinnanttemplate <size_t _Ip, class _Tp, size_t _Size>
4453af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
4463e519524SHoward Hinnant_Tp&
4478f0cd597SHoward Hinnantget(array<_Tp, _Size>& __a) _NOEXCEPT
4483e519524SHoward Hinnant{
44936a60721SMarshall Clow    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
4508bf1f08aSMarshall Clow    return __a.__elems_[_Ip];
4513e519524SHoward Hinnant}
4523e519524SHoward Hinnant
4533e519524SHoward Hinnanttemplate <size_t _Ip, class _Tp, size_t _Size>
4543af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
4553e519524SHoward Hinnantconst _Tp&
4568f0cd597SHoward Hinnantget(const array<_Tp, _Size>& __a) _NOEXCEPT
4573e519524SHoward Hinnant{
45836a60721SMarshall Clow    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
4598bf1f08aSMarshall Clow    return __a.__elems_[_Ip];
4603e519524SHoward Hinnant}
4613e519524SHoward Hinnant
462601afb30SHoward Hinnanttemplate <size_t _Ip, class _Tp, size_t _Size>
4633af48ef7SHoward Hinnantinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
464601afb30SHoward Hinnant_Tp&&
4658f0cd597SHoward Hinnantget(array<_Tp, _Size>&& __a) _NOEXCEPT
466601afb30SHoward Hinnant{
46736a60721SMarshall Clow    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
4688bf1f08aSMarshall Clow    return _VSTD::move(__a.__elems_[_Ip]);
469601afb30SHoward Hinnant}
470601afb30SHoward Hinnant
471545b8861SEric Fiseliertemplate <size_t _Ip, class _Tp, size_t _Size>
472545b8861SEric Fiselierinline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
473545b8861SEric Fiselierconst _Tp&&
474545b8861SEric Fiselierget(const array<_Tp, _Size>&& __a) _NOEXCEPT
475545b8861SEric Fiselier{
476545b8861SEric Fiselier    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
477545b8861SEric Fiselier    return _VSTD::move(__a.__elems_[_Ip]);
478545b8861SEric Fiselier}
479545b8861SEric Fiselier
480e93e58c6SMarek Kurdej#if _LIBCPP_STD_VER > 17
481e93e58c6SMarek Kurdej
482e93e58c6SMarek Kurdejtemplate <typename _Tp, size_t _Size, size_t... _Index>
483e93e58c6SMarek Kurdej_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
484e93e58c6SMarek Kurdej__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
485e93e58c6SMarek Kurdej  return {{__arr[_Index]...}};
486e93e58c6SMarek Kurdej}
487e93e58c6SMarek Kurdej
488e93e58c6SMarek Kurdejtemplate <typename _Tp, size_t _Size, size_t... _Index>
489e93e58c6SMarek Kurdej_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
490e93e58c6SMarek Kurdej__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
491e93e58c6SMarek Kurdej  return {{_VSTD::move(__arr[_Index])...}};
492e93e58c6SMarek Kurdej}
493e93e58c6SMarek Kurdej
494e93e58c6SMarek Kurdejtemplate <typename _Tp, size_t _Size>
495e93e58c6SMarek Kurdej_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
496e93e58c6SMarek Kurdejto_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
497e93e58c6SMarek Kurdej  static_assert(
498e93e58c6SMarek Kurdej      !is_array_v<_Tp>,
499e93e58c6SMarek Kurdej      "[array.creation]/1: to_array does not accept multidimensional arrays.");
500e93e58c6SMarek Kurdej  static_assert(
501e93e58c6SMarek Kurdej      is_constructible_v<_Tp, _Tp&>,
502e93e58c6SMarek Kurdej      "[array.creation]/1: to_array requires copy constructible elements.");
503781c476cSArthur O'Dwyer  return _VSTD::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
504e93e58c6SMarek Kurdej}
505e93e58c6SMarek Kurdej
506e93e58c6SMarek Kurdejtemplate <typename _Tp, size_t _Size>
507e93e58c6SMarek Kurdej_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
508e93e58c6SMarek Kurdejto_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
509e93e58c6SMarek Kurdej  static_assert(
510e93e58c6SMarek Kurdej      !is_array_v<_Tp>,
511e93e58c6SMarek Kurdej      "[array.creation]/4: to_array does not accept multidimensional arrays.");
512e93e58c6SMarek Kurdej  static_assert(
513e93e58c6SMarek Kurdej      is_move_constructible_v<_Tp>,
514e93e58c6SMarek Kurdej      "[array.creation]/4: to_array requires move constructible elements.");
515781c476cSArthur O'Dwyer  return _VSTD::__to_array_rvalue_impl(_VSTD::move(__arr),
516e93e58c6SMarek Kurdej                                       make_index_sequence<_Size>());
517e93e58c6SMarek Kurdej}
518e93e58c6SMarek Kurdej
519e93e58c6SMarek Kurdej#endif // _LIBCPP_STD_VER > 17
520e93e58c6SMarek Kurdej
5213e519524SHoward Hinnant_LIBCPP_END_NAMESPACE_STD
5223e519524SHoward Hinnant
5233e519524SHoward Hinnant#endif // _LIBCPP_ARRAY
524