lib: establish Zircon libc++ and KTL foundation

1 files changed, 609 insertions, 0 deletions

diff --git a/third_party/libcxx/include/c++/v1/array b/third_party/libcxx/include/c++/v1/array
new file mode 100644
index 0000000..0b0c854
--- /dev/null
+++ b/third_party/libcxx/include/c++/v1/array
@@ -0,0 +1,609 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ARRAY
+#define _LIBCPP_ARRAY
+
+/*
+    array synopsis
+
+namespace std
+{
+template <class T, size_t N >
+struct array
+{
+    // types:
+    using value_type             = T;
+    using pointer                = T*;
+    using const_pointer          = const T*;
+    using reference              = T&;
+    using const_reference        = const T&;
+    using size_type              = size_t;
+    using difference_type        = ptrdiff_t;
+    using iterator               = implementation-defined;
+    using const_iterator         = implementation-defined;
+    using reverse_iterator       = std::reverse_iterator<iterator>;
+    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+
+    // No explicit construct/copy/destroy for aggregate type
+    void fill(const T& u);                                      // constexpr in C++20
+    void swap(array& a) noexcept(is_nothrow_swappable_v<T>);    // constexpr in C++20
+
+    // iterators:
+    iterator begin() noexcept;                                  // constexpr in C++17
+    const_iterator begin() const noexcept;                      // constexpr in C++17
+    iterator end() noexcept;                                    // constexpr in C++17
+    const_iterator end() const noexcept;                        // constexpr in C++17
+
+    reverse_iterator rbegin() noexcept;                         // constexpr in C++17
+    const_reverse_iterator rbegin() const noexcept;             // constexpr in C++17
+    reverse_iterator rend() noexcept;                           // constexpr in C++17
+    const_reverse_iterator rend() const noexcept;               // constexpr in C++17
+
+    const_iterator cbegin() const noexcept;                     // constexpr in C++17
+    const_iterator cend() const noexcept;                       // constexpr in C++17
+    const_reverse_iterator crbegin() const noexcept;            // constexpr in C++17
+    const_reverse_iterator crend() const noexcept;              // constexpr in C++17
+
+    // capacity:
+    constexpr size_type size() const noexcept;
+    constexpr size_type max_size() const noexcept;
+    constexpr bool empty() const noexcept;
+
+    // element access:
+    reference operator[](size_type n);                          // constexpr in C++17
+    const_reference operator[](size_type n) const;              // constexpr in C++14
+    reference at(size_type n);                                  // constexpr in C++17
+    const_reference at(size_type n) const;                      // constexpr in C++14
+
+    reference front();                                          // constexpr in C++17
+    const_reference front() const;                              // constexpr in C++14
+    reference back();                                           // constexpr in C++17
+    const_reference back() const;                               // constexpr in C++14
+
+    T* data() noexcept;                                         // constexpr in C++17
+    const T* data() const noexcept;                             // constexpr in C++17
+};
+
+template <class T, class... U>
+  array(T, U...) -> array<T, 1 + sizeof...(U)>;                 // C++17
+
+template <class T, size_t N>
+  bool operator==(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
+template <class T, size_t N>
+  bool operator!=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
+template <class T, size_t N>
+  bool operator<(const array<T,N>& x, const array<T,N>& y);     // removed in C++20
+template <class T, size_t N>
+  bool operator>(const array<T,N>& x, const array<T,N>& y);     // removed in C++20
+template <class T, size_t N>
+  bool operator<=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
+template <class T, size_t N>
+  bool operator>=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
+template<class T, size_t N>
+  constexpr synth-three-way-result<T>
+    operator<=>(const array<T, N>& x, const array<T, N>& y);    // since C++20
+
+template <class T, size_t N >
+  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // constexpr in C++20
+
+template <class T, size_t N>
+  constexpr array<remove_cv_t<T>, N> to_array(T (&a)[N]);  // C++20
+template <class T, size_t N>
+  constexpr array<remove_cv_t<T>, N> to_array(T (&&a)[N]); // C++20
+
+template <class T> struct tuple_size;
+template <size_t I, class T> struct tuple_element;
+template <class T, size_t N> struct tuple_size<array<T, N>>;
+template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
+template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept;               // constexpr in C++14
+template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept;   // constexpr in C++14
+template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept;             // constexpr in C++14
+template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
+
+}  // std
+
+*/
+
+#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
+#  include <__cxx03/array>
+#else
+#  include <__algorithm/equal.h>
+#  include <__algorithm/fill_n.h>
+#  include <__algorithm/lexicographical_compare.h>
+#  include <__algorithm/lexicographical_compare_three_way.h>
+#  include <__algorithm/swap_ranges.h>
+#  include <__assert>
+#  include <__config>
+#  include <__cstddef/ptrdiff_t.h>
+#  include <__fwd/array.h>
+#  include <__iterator/reverse_iterator.h>
+#  include <__iterator/static_bounded_iter.h>
+#  include <__iterator/wrap_iter.h>
+#  include <__tuple/sfinae_helpers.h>
+#  include <__type_traits/conditional.h>
+#  include <__type_traits/conjunction.h>
+#  include <__type_traits/enable_if.h>
+#  include <__type_traits/is_array.h>
+#  include <__type_traits/is_const.h>
+#  include <__type_traits/is_constructible.h>
+#  include <__type_traits/is_nothrow_constructible.h>
+#  include <__type_traits/is_same.h>
+#  include <__type_traits/is_swappable.h>
+#  include <__type_traits/is_trivially_relocatable.h>
+#  include <__type_traits/remove_cv.h>
+#  include <__utility/empty.h>
+#  include <__utility/integer_sequence.h>
+#  include <__utility/move.h>
+#  include <__utility/unreachable.h>
+#  include <stdexcept>
+#  include <version>
+
+// standard-mandated includes
+
+// [iterator.range]
+#  include <__iterator/access.h>
+#  include <__iterator/data.h>
+#  include <__iterator/empty.h>
+#  include <__iterator/reverse_access.h>
+#  include <__iterator/size.h>
+
+// [array.syn]
+#  include <compare>
+#  include <initializer_list>
+
+// [tuple.helper]
+#  include <__tuple/tuple_element.h>
+#  include <__tuple/tuple_size.h>
+
+#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#    pragma GCC system_header
+#  endif
+
+_LIBCPP_PUSH_MACROS
+#  include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, size_t _Size>
+struct array {
+  using __trivially_relocatable _LIBCPP_NODEBUG =
+      __conditional_t<__libcpp_is_trivially_relocatable<_Tp>::value, array, void>;
+
+  // types:
+  using __self _LIBCPP_NODEBUG = array;
+  using value_type             = _Tp;
+  using reference              = value_type&;
+  using const_reference        = const value_type&;
+  using pointer                = value_type*;
+  using const_pointer          = const value_type*;
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+  using iterator       = __static_bounded_iter<pointer, _Size>;
+  using const_iterator = __static_bounded_iter<const_pointer, _Size>;
+#  elif defined(_LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY)
+  using iterator       = __wrap_iter<pointer>;
+  using const_iterator = __wrap_iter<const_pointer>;
+#  else
+  using iterator       = pointer;
+  using const_iterator = const_pointer;
+#  endif
+  using size_type              = size_t;
+  using difference_type        = ptrdiff_t;
+  using reverse_iterator       = std::reverse_iterator<iterator>;
+  using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+
+  _Tp __elems_[_Size];
+
+  // No explicit construct/copy/destroy for aggregate type
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void fill(const value_type& __u) {
+    std::fill_n(data(), _Size, __u);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable_v<_Tp>) {
+    std::swap_ranges(data(), data() + _Size, __a.data());
+  }
+
+  // iterators:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 iterator begin() _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<_Size>(data(), data());
+#  else
+    return iterator(data());
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator begin() const _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<_Size>(data(), data());
+#  else
+    return const_iterator(data());
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 iterator end() _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<_Size>(data() + _Size, data());
+#  else
+    return iterator(data() + _Size);
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator end() const _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<_Size>(data() + _Size, data());
+#  else
+    return const_iterator(data() + _Size);
+#  endif
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reverse_iterator rbegin() _NOEXCEPT {
+    return reverse_iterator(end());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator
+  rbegin() const _NOEXCEPT {
+    return const_reverse_iterator(end());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reverse_iterator rend() _NOEXCEPT {
+    return reverse_iterator(begin());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator rend() const _NOEXCEPT {
+    return const_reverse_iterator(begin());
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator cbegin() const _NOEXCEPT {
+    return begin();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator cend() const _NOEXCEPT {
+    return end();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator
+  crbegin() const _NOEXCEPT {
+    return rbegin();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator crend() const _NOEXCEPT {
+    return rend();
+  }
+
+  // capacity:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT { return _Size; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT { return _Size; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT { return _Size == 0; }
+
+  // element access:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference operator[](size_type __n) _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < _Size, "out-of-bounds access in std::array<T, N>");
+    return __elems_[__n];
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference
+  operator[](size_type __n) const _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < _Size, "out-of-bounds access in std::array<T, N>");
+    return __elems_[__n];
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference at(size_type __n) {
+    if (__n >= _Size)
+      std::__throw_out_of_range("array::at");
+    return __elems_[__n];
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference at(size_type __n) const {
+    if (__n >= _Size)
+      std::__throw_out_of_range("array::at");
+    return __elems_[__n];
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference front() _NOEXCEPT {
+    return (*this)[0];
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference front() const _NOEXCEPT {
+    return (*this)[0];
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference back() _NOEXCEPT {
+    return (*this)[_Size - 1];
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference back() const _NOEXCEPT {
+    return (*this)[_Size - 1];
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 value_type* data() _NOEXCEPT {
+    return __elems_;
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const value_type* data() const _NOEXCEPT {
+    return __elems_;
+  }
+};
+
+template <class _Tp>
+struct array<_Tp, 0> {
+  // types:
+  using __self _LIBCPP_NODEBUG = array;
+  using value_type             = _Tp;
+  using reference              = value_type&;
+  using const_reference        = const value_type&;
+  using pointer                = value_type*;
+  using const_pointer          = const value_type*;
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+  using iterator       = __static_bounded_iter<pointer, 0>;
+  using const_iterator = __static_bounded_iter<const_pointer, 0>;
+#  elif defined(_LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY)
+  using iterator       = __wrap_iter<pointer>;
+  using const_iterator = __wrap_iter<const_pointer>;
+#  else
+  using iterator       = pointer;
+  using const_iterator = const_pointer;
+#  endif
+  using size_type              = size_t;
+  using difference_type        = ptrdiff_t;
+  using reverse_iterator       = std::reverse_iterator<iterator>;
+  using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+
+  using _EmptyType _LIBCPP_NODEBUG = __conditional_t<is_const<_Tp>::value, const __empty, __empty>;
+
+  struct _ArrayInStructT {
+    _Tp __data_[1];
+  };
+  _ALIGNAS_TYPE(_ArrayInStructT) _EmptyType __elems_[sizeof(_ArrayInStructT)];
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 value_type* data() _NOEXCEPT { return nullptr; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const value_type* data() const _NOEXCEPT {
+    return nullptr;
+  }
+
+  // No explicit construct/copy/destroy for aggregate type
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void fill(const value_type&) {
+    static_assert(!is_const<_Tp>::value, "cannot fill zero-sized array of type 'const T'");
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(array&) _NOEXCEPT {
+    static_assert(!is_const<_Tp>::value, "cannot swap zero-sized array of type 'const T'");
+  }
+
+  // iterators:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 iterator begin() _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<0>(data(), data());
+#  else
+    return iterator(data());
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator begin() const _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<0>(data(), data());
+#  else
+    return const_iterator(data());
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 iterator end() _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<0>(data(), data());
+#  else
+    return iterator(data());
+#  endif
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator end() const _NOEXCEPT {
+#  if defined(_LIBCPP_ABI_BOUNDED_ITERATORS_IN_STD_ARRAY)
+    return std::__make_static_bounded_iter<0>(data(), data());
+#  else
+    return const_iterator(data());
+#  endif
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reverse_iterator rbegin() _NOEXCEPT {
+    return reverse_iterator(end());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator
+  rbegin() const _NOEXCEPT {
+    return const_reverse_iterator(end());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reverse_iterator rend() _NOEXCEPT {
+    return reverse_iterator(begin());
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator rend() const _NOEXCEPT {
+    return const_reverse_iterator(begin());
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator cbegin() const _NOEXCEPT {
+    return begin();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_iterator cend() const _NOEXCEPT {
+    return end();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator
+  crbegin() const _NOEXCEPT {
+    return rbegin();
+  }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 const_reverse_iterator crend() const _NOEXCEPT {
+    return rend();
+  }
+
+  // capacity:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT { return 0; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT { return 0; }
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT { return true; }
+
+  // element access:
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference operator[](size_type) _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference
+  operator[](size_type) const _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference at(size_type) {
+    std::__throw_out_of_range("array<T, 0>::at");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference at(size_type) const {
+    std::__throw_out_of_range("array<T, 0>::at");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference front() _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::front() on a zero-sized array");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference front() const _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::front() on a zero-sized array");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference back() _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::back() on a zero-sized array");
+    __libcpp_unreachable();
+  }
+
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference back() const _NOEXCEPT {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::back() on a zero-sized array");
+    __libcpp_unreachable();
+  }
+};
+
+#  if _LIBCPP_STD_VER >= 17
+template <class _Tp, class... _Args, class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value> >
+array(_Tp, _Args...) -> array<_Tp, 1 + sizeof...(_Args)>;
+#  endif
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
+operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return std::equal(__x.begin(), __x.end(), __y.begin());
+}
+
+#  if _LIBCPP_STD_VER <= 17
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return !(__x == __y);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI bool operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return std::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI bool operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return __y < __x;
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return !(__y < __x);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return !(__x < __y);
+}
+
+#  else // _LIBCPP_STD_VER <= 17
+
+template <class _Tp, size_t _Size>
+_LIBCPP_HIDE_FROM_ABI constexpr __synth_three_way_result<_Tp>
+operator<=>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
+  return std::lexicographical_compare_three_way(__x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way);
+}
+
+#  endif // _LIBCPP_STD_VER <= 17
+
+template <class _Tp, size_t _Size, __enable_if_t<_Size == 0 || __is_swappable_v<_Tp>, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
+    _NOEXCEPT_(noexcept(__x.swap(__y))) {
+  __x.swap(__y);
+}
+
+template <class _Tp, size_t _Size>
+struct tuple_size<array<_Tp, _Size> > : public integral_constant<size_t, _Size> {};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+struct tuple_element<_Ip, array<_Tp, _Size> > {
+  static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
+  using type _LIBCPP_NODEBUG = _Tp;
+};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp&
+get(array<_Tp, _Size>& __a) _NOEXCEPT {
+  static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
+  return __a.__elems_[_Ip];
+}
+
+template <size_t _Ip, class _Tp, size_t _Size>
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _Tp&
+get(const array<_Tp, _Size>& __a) _NOEXCEPT {
+  static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
+  return __a.__elems_[_Ip];
+}
+
+template <size_t _Ip, class _Tp, size_t _Size>
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp&&
+get(array<_Tp, _Size>&& __a) _NOEXCEPT {
+  static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
+  return std::move(__a.__elems_[_Ip]);
+}
+
+template <size_t _Ip, class _Tp, size_t _Size>
+[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const _Tp&&
+get(const array<_Tp, _Size>&& __a) _NOEXCEPT {
+  static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
+  return std::move(__a.__elems_[_Ip]);
+}
+
+#  if _LIBCPP_STD_VER >= 20
+
+template <typename _Tp, size_t _Size, size_t... _Index>
+_LIBCPP_HIDE_FROM_ABI constexpr array<remove_cv_t<_Tp>, _Size>
+__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
+  return {{__arr[_Index]...}};
+}
+
+template <typename _Tp, size_t _Size, size_t... _Index>
+_LIBCPP_HIDE_FROM_ABI constexpr array<remove_cv_t<_Tp>, _Size>
+__to_array_rvalue_impl(_Tp (&&__arr)[_Size], index_sequence<_Index...>) {
+  return {{std::move(__arr[_Index])...}};
+}
+
+template <typename _Tp, size_t _Size>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr array<remove_cv_t<_Tp>, _Size>
+to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
+  static_assert(!is_array_v<_Tp>, "[array.creation]/1: to_array does not accept multidimensional arrays.");
+  static_assert(is_constructible_v<_Tp, _Tp&>, "[array.creation]/1: to_array requires copy constructible elements.");
+  return std::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
+}
+
+template <typename _Tp, size_t _Size>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr array<remove_cv_t<_Tp>, _Size>
+to_array(_Tp (&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
+  static_assert(!is_array_v<_Tp>, "[array.creation]/4: to_array does not accept multidimensional arrays.");
+  static_assert(is_move_constructible_v<_Tp>, "[array.creation]/4: to_array requires move constructible elements.");
+  return std::__to_array_rvalue_impl(std::move(__arr), make_index_sequence<_Size>());
+}
+
+#  endif // _LIBCPP_STD_VER >= 20
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
+#    include <algorithm>
+#    include <concepts>
+#    include <cstdlib>
+#    include <iterator>
+#    include <new>
+#    include <optional>
+#    include <type_traits>
+#    include <utility>
+#  endif
+#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
+
+#endif // _LIBCPP_ARRAY