libstdc++-v3/include/std/array - gcc - Git at Google

 // <array> -*- C++ -*-

 // Copyright (C) 2007-2020 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
 // terms of the GNU General Public License as published by the
 // Free Software Foundation; either version 3, or (at your option)
 // any later version.

 // This library is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.

 // Under Section 7 of GPL version 3, you are granted additional
 // permissions described in the GCC Runtime Library Exception, version
 // 3.1, as published by the Free Software Foundation.

 // You should have received a copy of the GNU General Public License and
 // a copy of the GCC Runtime Library Exception along with this program;
 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 // <http://www.gnu.org/licenses/>.

 /** @file include/array
  *  This is a Standard C++ Library header.
  */

 #ifndef _GLIBCXX_ARRAY
 #define _GLIBCXX_ARRAY 1

 #pragma GCC system_header

 #if __cplusplus < 201103L
 # include <bits/c++0x_warning.h>
 #else

 #include <utility>
 #include <bits/functexcept.h>
 #include <bits/stl_algobase.h>
 #include <bits/range_access.h>

 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER

   template<typename _Tp, std::size_t _Nm>
     struct __array_traits
     {
       typedef _Tp _Type[_Nm];
       typedef __is_swappable<_Tp> _Is_swappable;
       typedef __is_nothrow_swappable<_Tp> _Is_nothrow_swappable;

       static constexpr _Tp&
       _S_ref(const _Type& __t, std::size_t __n) noexcept
       { return const_cast<_Tp&>(__t[__n]); }

       static constexpr _Tp*
       _S_ptr(const _Type& __t) noexcept
       { return const_cast<_Tp*>(__t); }
     };

  template<typename _Tp>
    struct __array_traits<_Tp, 0>
    {
      struct _Type { };
      typedef true_type _Is_swappable;
      typedef true_type _Is_nothrow_swappable;

      static constexpr _Tp&
      _S_ref(const _Type&, std::size_t) noexcept
      { return *static_cast<_Tp*>(nullptr); }

      static constexpr _Tp*
      _S_ptr(const _Type&) noexcept
      { return nullptr; }
    };

   /**
    *  @brief A standard container for storing a fixed size sequence of elements.
    *
    *  @ingroup sequences
    *
    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
    *  <a href="tables.html#66">reversible container</a>, and a
    *  <a href="tables.html#67">sequence</a>.
    *
    *  Sets support random access iterators.
    *
    *  @tparam  Tp  Type of element. Required to be a complete type.
    *  @tparam  Nm  Number of elements.
   */
   template<typename _Tp, std::size_t _Nm>
     struct array
     {
       typedef _Tp 	    			      value_type;
       typedef value_type*			      pointer;
       typedef const value_type*                       const_pointer;
       typedef value_type&                   	      reference;
       typedef const value_type&             	      const_reference;
       typedef value_type*          		      iterator;
       typedef const value_type*			      const_iterator;
       typedef std::size_t                    	      size_type;
       typedef std::ptrdiff_t                   	      difference_type;
       typedef std::reverse_iterator<iterator>	      reverse_iterator;
       typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;

       // Support for zero-sized arrays mandatory.
       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
       typename _AT_Type::_Type                         _M_elems;

       // No explicit construct/copy/destroy for aggregate type.

       // DR 776.
       _GLIBCXX20_CONSTEXPR void
       fill(const value_type& __u)
       { std::fill_n(begin(), size(), __u); }

       _GLIBCXX20_CONSTEXPR void
       swap(array& __other)
       noexcept(_AT_Type::_Is_nothrow_swappable::value)
       { std::swap_ranges(begin(), end(), __other.begin()); }

       // Iterators.
       _GLIBCXX17_CONSTEXPR iterator
       begin() noexcept
       { return iterator(data()); }

       _GLIBCXX17_CONSTEXPR const_iterator
       begin() const noexcept
       { return const_iterator(data()); }

       _GLIBCXX17_CONSTEXPR iterator
       end() noexcept
       { return iterator(data() + _Nm); }

       _GLIBCXX17_CONSTEXPR const_iterator
       end() const noexcept
       { return const_iterator(data() + _Nm); }

       _GLIBCXX17_CONSTEXPR reverse_iterator
       rbegin() noexcept
       { return reverse_iterator(end()); }

       _GLIBCXX17_CONSTEXPR const_reverse_iterator
       rbegin() const noexcept
       { return const_reverse_iterator(end()); }

       _GLIBCXX17_CONSTEXPR reverse_iterator
       rend() noexcept
       { return reverse_iterator(begin()); }

       _GLIBCXX17_CONSTEXPR const_reverse_iterator
       rend() const noexcept
       { return const_reverse_iterator(begin()); }

       _GLIBCXX17_CONSTEXPR const_iterator
       cbegin() const noexcept
       { return const_iterator(data()); }

       _GLIBCXX17_CONSTEXPR const_iterator
       cend() const noexcept
       { return const_iterator(data() + _Nm); }

       _GLIBCXX17_CONSTEXPR const_reverse_iterator
       crbegin() const noexcept
       { return const_reverse_iterator(end()); }

       _GLIBCXX17_CONSTEXPR const_reverse_iterator
       crend() const noexcept
       { return const_reverse_iterator(begin()); }

       // Capacity.
       constexpr size_type
       size() const noexcept { return _Nm; }

       constexpr size_type
       max_size() const noexcept { return _Nm; }

       _GLIBCXX_NODISCARD constexpr bool
       empty() const noexcept { return size() == 0; }

       // Element access.
       _GLIBCXX17_CONSTEXPR reference
       operator[](size_type __n) noexcept
       { return _AT_Type::_S_ref(_M_elems, __n); }

       constexpr const_reference
       operator[](size_type __n) const noexcept
       { return _AT_Type::_S_ref(_M_elems, __n); }

       _GLIBCXX17_CONSTEXPR reference
       at(size_type __n)
       {
 	if (__n >= _Nm)
 	  std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 					    ">= _Nm (which is %zu)"),
 					__n, _Nm);
 	return _AT_Type::_S_ref(_M_elems, __n);
       }

       constexpr const_reference
       at(size_type __n) const
       {
 	// Result of conditional expression must be an lvalue so use
 	// boolean ? lvalue : (throw-expr, lvalue)
 	return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
 	  : (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 					       ">= _Nm (which is %zu)"),
 					   __n, _Nm),
 	     _AT_Type::_S_ref(_M_elems, 0));
       }

       _GLIBCXX17_CONSTEXPR reference
       front() noexcept
       { return *begin(); }

       constexpr const_reference
       front() const noexcept
       { return _AT_Type::_S_ref(_M_elems, 0); }

       _GLIBCXX17_CONSTEXPR reference
       back() noexcept
       { return _Nm ? *(end() - 1) : *end(); }

       constexpr const_reference
       back() const noexcept
       {
 	return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
  	           : _AT_Type::_S_ref(_M_elems, 0);
       }

       _GLIBCXX17_CONSTEXPR pointer
       data() noexcept
       { return _AT_Type::_S_ptr(_M_elems); }

       _GLIBCXX17_CONSTEXPR const_pointer
       data() const noexcept
       { return _AT_Type::_S_ptr(_M_elems); }
     };

 #if __cpp_deduction_guides >= 201606
   template<typename _Tp, typename... _Up>
     array(_Tp, _Up...)
       -> array<enable_if_t<(is_same_v<_Tp, _Up> && ...), _Tp>,
 	       1 + sizeof...(_Up)>;
 #endif

   // Array comparisons.
   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
     { return std::equal(__one.begin(), __one.end(), __two.begin()); }

 #if __cpp_lib_three_way_comparison && __cpp_lib_concepts
   template<typename _Tp, size_t _Nm>
     constexpr __detail::__synth3way_t<_Tp>
     operator<=>(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
     {
 #ifdef __cpp_lib_is_constant_evaluated
       if constexpr (_Nm && __is_memcmp_ordered<_Tp>::__value)
 	if (!std::is_constant_evaluated())
 	  {
 	    constexpr size_t __n = _Nm * sizeof(_Tp);
 	    return __builtin_memcmp(__a.data(), __b.data(), __n) <=> 0;
 	  }
 #endif

       for (size_t __i = 0; __i < _Nm; ++__i)
 	{
 	  auto __c = __detail::__synth3way(__a[__i], __b[__i]);
 	  if (__c != 0)
 	    return __c;
 	}
       return strong_ordering::equal;
     }
 #else
   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
     { return !(__one == __two); }

   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
     {
       return std::lexicographical_compare(__a.begin(), __a.end(),
 					  __b.begin(), __b.end());
     }

   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
     { return __two < __one; }

   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
     { return !(__one > __two); }

   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline bool
     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
     { return !(__one < __two); }
 #endif // three_way_comparison && concepts

   // Specialized algorithms.
   template<typename _Tp, std::size_t _Nm>
     _GLIBCXX20_CONSTEXPR
     inline
 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
     // Constrained free swap overload, see p0185r1
     typename enable_if<
       _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value
     >::type
 #else
     void
 #endif
     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
     noexcept(noexcept(__one.swap(__two)))
     { __one.swap(__two); }

 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
   template<typename _Tp, std::size_t _Nm>
     typename enable_if<
       !_GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value>::type
     swap(array<_Tp, _Nm>&, array<_Tp, _Nm>&) = delete;
 #endif

   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     constexpr _Tp&
     get(array<_Tp, _Nm>& __arr) noexcept
     {
       static_assert(_Int < _Nm, "array index is within bounds");
       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 	_S_ref(__arr._M_elems, _Int);
     }

   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     constexpr _Tp&&
     get(array<_Tp, _Nm>&& __arr) noexcept
     {
       static_assert(_Int < _Nm, "array index is within bounds");
       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
     }

   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     constexpr const _Tp&
     get(const array<_Tp, _Nm>& __arr) noexcept
     {
       static_assert(_Int < _Nm, "array index is within bounds");
       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 	_S_ref(__arr._M_elems, _Int);
     }

   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     constexpr const _Tp&&
     get(const array<_Tp, _Nm>&& __arr) noexcept
     {
       static_assert(_Int < _Nm, "array index is within bounds");
       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
     }

 #if __cplusplus > 201703L
 #define __cpp_lib_to_array 201907L

   template<bool _Move = false, typename _Tp, size_t... _Idx>
     constexpr array<remove_cv_t<_Tp>, sizeof...(_Idx)>
     __to_array(_Tp (&__a)[sizeof...(_Idx)], index_sequence<_Idx...>)
     {
       if constexpr (_Move)
 	return {{std::move(__a[_Idx])...}};
       else
 	return {{__a[_Idx]...}};
     }

   template<typename _Tp, size_t _Nm>
     constexpr array<remove_cv_t<_Tp>, _Nm>
     to_array(_Tp (&__a)[_Nm])
     noexcept(is_nothrow_constructible_v<_Tp, _Tp&>)
     {
       static_assert(!is_array_v<_Tp>);
       static_assert(is_constructible_v<_Tp, _Tp&>);
       if constexpr (is_constructible_v<_Tp, _Tp&>)
 	return _GLIBCXX_STD_C::__to_array(__a, make_index_sequence<_Nm>{});
       __builtin_unreachable(); // FIXME: see PR c++/91388
     }

   template<typename _Tp, size_t _Nm>
     constexpr array<remove_cv_t<_Tp>, _Nm>
     to_array(_Tp (&&__a)[_Nm])
     noexcept(is_nothrow_move_constructible_v<_Tp>)
     {
       static_assert(!is_array_v<_Tp>);
       static_assert(is_move_constructible_v<_Tp>);
       if constexpr (is_move_constructible_v<_Tp>)
 	return _GLIBCXX_STD_C::__to_array<1>(__a, make_index_sequence<_Nm>{});
       __builtin_unreachable(); // FIXME: see PR c++/91388
     }
 #endif // C++20

 _GLIBCXX_END_NAMESPACE_CONTAINER
 } // namespace std

 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION

   // Tuple interface to class template array.

   /// tuple_size
   template<typename _Tp>
     struct tuple_size;

   /// Partial specialization for std::array
   template<typename _Tp, std::size_t _Nm>
     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
     : public integral_constant<std::size_t, _Nm> { };

   /// tuple_element
   template<std::size_t _Int, typename _Tp>
     struct tuple_element;

   /// Partial specialization for std::array
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
     {
       static_assert(_Int < _Nm, "index is out of bounds");
       typedef _Tp type;
     };

   template<typename _Tp, std::size_t _Nm>
     struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
     { };

 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std

 #ifdef _GLIBCXX_DEBUG
 # include <debug/array>
 #endif

 #endif // C++11

 #endif // _GLIBCXX_ARRAY
	// <array> -- C++ --

	// Copyright (C) 2007-2020 Free Software Foundation, Inc.
	//
	// This file is part of the GNU ISO C++ Library. This library is free
	// software; you can redistribute it and/or modify it under the
	// terms of the GNU General Public License as published by the
	// Free Software Foundation; either version 3, or (at your option)
	// any later version.

	// This library is distributed in the hope that it will be useful,
	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	// GNU General Public License for more details.

	// Under Section 7 of GPL version 3, you are granted additional
	// permissions described in the GCC Runtime Library Exception, version
	// 3.1, as published by the Free Software Foundation.

	// You should have received a copy of the GNU General Public License and
	// a copy of the GCC Runtime Library Exception along with this program;
	// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
	// <http://www.gnu.org/licenses/>.

	/** @file include/array
	* This is a Standard C++ Library header.
	*/

	#ifndef _GLIBCXX_ARRAY
	#define _GLIBCXX_ARRAY 1

	#pragma GCC system_header

	#if __cplusplus < 201103L
	# include <bits/c++0x_warning.h>
	#else

	#include <utility>
	#include <bits/functexcept.h>
	#include <bits/stl_algobase.h>
	#include <bits/range_access.h>

	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_CONTAINER

	template<typename _Tp, std::size_t _Nm>
	struct __array_traits
	{
	typedef _Tp _Type[_Nm];
	typedef __is_swappable<_Tp> _Is_swappable;
	typedef __is_nothrow_swappable<_Tp> _Is_nothrow_swappable;

	static constexpr _Tp&
	_S_ref(const _Type& __t, std::size_t __n) noexcept
	{ return const_cast<_Tp&>(__t[__n]); }

	static constexpr _Tp*
	_S_ptr(const _Type& __t) noexcept
	{ return const_cast<_Tp*>(__t); }
	};

	template<typename _Tp>
	struct __array_traits<_Tp, 0>
	{
	struct _Type { };
	typedef true_type _Is_swappable;
	typedef true_type _Is_nothrow_swappable;

	static constexpr _Tp&
	_S_ref(const _Type&, std::size_t) noexcept
	{ return static_cast<_Tp>(nullptr); }

	static constexpr _Tp*
	_S_ptr(const _Type&) noexcept
	{ return nullptr; }
	};

	/**
	* @brief A standard container for storing a fixed size sequence of elements.
	*
	* @ingroup sequences
	*
	* Meets the requirements of a <a href="tables.html#65">container</a>, a
	* <a href="tables.html#66">reversible container</a>, and a
	* <a href="tables.html#67">sequence</a>.
	*
	* Sets support random access iterators.
	*
	* @tparam Tp Type of element. Required to be a complete type.
	* @tparam Nm Number of elements.
	*/
	template<typename _Tp, std::size_t _Nm>
	struct array
	{
	typedef _Tp value_type;
	typedef value_type* pointer;
	typedef const value_type* const_pointer;
	typedef value_type& reference;
	typedef const value_type& const_reference;
	typedef value_type* iterator;
	typedef const value_type* const_iterator;
	typedef std::size_t size_type;
	typedef std::ptrdiff_t difference_type;
	typedef std::reverse_iterator<iterator> reverse_iterator;
	typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

	// Support for zero-sized arrays mandatory.
	typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
	typename _AT_Type::_Type _M_elems;

	// No explicit construct/copy/destroy for aggregate type.

	// DR 776.
	_GLIBCXX20_CONSTEXPR void
	fill(const value_type& __u)
	{ std::fill_n(begin(), size(), __u); }

	_GLIBCXX20_CONSTEXPR void
	swap(array& __other)
	noexcept(_AT_Type::_Is_nothrow_swappable::value)
	{ std::swap_ranges(begin(), end(), __other.begin()); }

	// Iterators.
	_GLIBCXX17_CONSTEXPR iterator
	begin() noexcept
	{ return iterator(data()); }

	_GLIBCXX17_CONSTEXPR const_iterator
	begin() const noexcept
	{ return const_iterator(data()); }

	_GLIBCXX17_CONSTEXPR iterator
	end() noexcept
	{ return iterator(data() + _Nm); }

	_GLIBCXX17_CONSTEXPR const_iterator
	end() const noexcept
	{ return const_iterator(data() + _Nm); }

	_GLIBCXX17_CONSTEXPR reverse_iterator
	rbegin() noexcept
	{ return reverse_iterator(end()); }

	_GLIBCXX17_CONSTEXPR const_reverse_iterator
	rbegin() const noexcept
	{ return const_reverse_iterator(end()); }

	_GLIBCXX17_CONSTEXPR reverse_iterator
	rend() noexcept
	{ return reverse_iterator(begin()); }

	_GLIBCXX17_CONSTEXPR const_reverse_iterator
	rend() const noexcept
	{ return const_reverse_iterator(begin()); }

	_GLIBCXX17_CONSTEXPR const_iterator
	cbegin() const noexcept
	{ return const_iterator(data()); }

	_GLIBCXX17_CONSTEXPR const_iterator
	cend() const noexcept
	{ return const_iterator(data() + _Nm); }

	_GLIBCXX17_CONSTEXPR const_reverse_iterator
	crbegin() const noexcept
	{ return const_reverse_iterator(end()); }

	_GLIBCXX17_CONSTEXPR const_reverse_iterator
	crend() const noexcept
	{ return const_reverse_iterator(begin()); }

	// Capacity.
	constexpr size_type
	size() const noexcept { return _Nm; }

	constexpr size_type
	max_size() const noexcept { return _Nm; }

	_GLIBCXX_NODISCARD constexpr bool
	empty() const noexcept { return size() == 0; }

	// Element access.
	_GLIBCXX17_CONSTEXPR reference
	operator[](size_type __n) noexcept
	{ return _AT_Type::_S_ref(_M_elems, __n); }

	constexpr const_reference
	operator[](size_type __n) const noexcept
	{ return _AT_Type::_S_ref(_M_elems, __n); }

	_GLIBCXX17_CONSTEXPR reference
	at(size_type __n)
	{
	if (__n >= _Nm)
	std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
	">= _Nm (which is %zu)"),
	__n, _Nm);
	return _AT_Type::_S_ref(_M_elems, __n);
	}

	constexpr const_reference
	at(size_type __n) const
	{
	// Result of conditional expression must be an lvalue so use
	// boolean ? lvalue : (throw-expr, lvalue)
	return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
	: (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
	">= _Nm (which is %zu)"),
	__n, _Nm),
	_AT_Type::_S_ref(_M_elems, 0));
	}

	_GLIBCXX17_CONSTEXPR reference
	front() noexcept
	{ return *begin(); }

	constexpr const_reference
	front() const noexcept
	{ return _AT_Type::_S_ref(_M_elems, 0); }

	_GLIBCXX17_CONSTEXPR reference
	back() noexcept
	{ return _Nm ? (end() - 1) : end(); }

	constexpr const_reference
	back() const noexcept
	{
	return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
	: _AT_Type::_S_ref(_M_elems, 0);
	}

	_GLIBCXX17_CONSTEXPR pointer
	data() noexcept
	{ return _AT_Type::_S_ptr(_M_elems); }

	_GLIBCXX17_CONSTEXPR const_pointer
	data() const noexcept
	{ return _AT_Type::_S_ptr(_M_elems); }
	};

	#if __cpp_deduction_guides >= 201606
	template<typename _Tp, typename... _Up>
	array(_Tp, _Up...)
	-> array<enable_if_t<(is_same_v<_Tp, _Up> && ...), _Tp>,
	1 + sizeof...(_Up)>;
	#endif

	// Array comparisons.
	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
	{ return std::equal(__one.begin(), __one.end(), __two.begin()); }

	#if __cpp_lib_three_way_comparison && __cpp_lib_concepts
	template<typename _Tp, size_t _Nm>
	constexpr __detail::__synth3way_t<_Tp>
	operator<=>(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
	{
	#ifdef __cpp_lib_is_constant_evaluated
	if constexpr (_Nm && __is_memcmp_ordered<_Tp>::__value)
	if (!std::is_constant_evaluated())
	{
	constexpr size_t __n = _Nm * sizeof(_Tp);
	return __builtin_memcmp(__a.data(), __b.data(), __n) <=> 0;
	}
	#endif

	for (size_t __i = 0; __i < _Nm; ++__i)
	{
	auto __c = __detail::__synth3way(__a[__i], __b[__i]);
	if (__c != 0)
	return __c;
	}
	return strong_ordering::equal;
	}
	#else
	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
	{ return !(__one == __two); }

	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
	{
	return std::lexicographical_compare(__a.begin(), __a.end(),
	__b.begin(), __b.end());
	}

	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
	{ return __two < __one; }

	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
	{ return !(__one > __two); }

	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline bool
	operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
	{ return !(__one < __two); }
	#endif // three_way_comparison && concepts

	// Specialized algorithms.
	template<typename _Tp, std::size_t _Nm>
	_GLIBCXX20_CONSTEXPR
	inline
	#if __cplusplus > 201402L \|\| !defined(__STRICT_ANSI__) // c++1z or gnu++11
	// Constrained free swap overload, see p0185r1
	typename enable_if<
	_GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value
	>::type
	#else
	void
	#endif
	swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
	noexcept(noexcept(__one.swap(__two)))
	{ __one.swap(__two); }

	#if __cplusplus > 201402L \|\| !defined(__STRICT_ANSI__) // c++1z or gnu++11
	template<typename _Tp, std::size_t _Nm>
	typename enable_if<
	!_GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value>::type
	swap(array<_Tp, _Nm>&, array<_Tp, _Nm>&) = delete;
	#endif

	template<std::size_t _Int, typename _Tp, std::size_t _Nm>
	constexpr _Tp&
	get(array<_Tp, _Nm>& __arr) noexcept
	{
	static_assert(_Int < _Nm, "array index is within bounds");
	return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
	_S_ref(__arr._M_elems, _Int);
	}

	template<std::size_t _Int, typename _Tp, std::size_t _Nm>
	constexpr _Tp&&
	get(array<_Tp, _Nm>&& __arr) noexcept
	{
	static_assert(_Int < _Nm, "array index is within bounds");
	return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
	}

	template<std::size_t _Int, typename _Tp, std::size_t _Nm>
	constexpr const _Tp&
	get(const array<_Tp, _Nm>& __arr) noexcept
	{
	static_assert(_Int < _Nm, "array index is within bounds");
	return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
	_S_ref(__arr._M_elems, _Int);
	}

	template<std::size_t _Int, typename _Tp, std::size_t _Nm>
	constexpr const _Tp&&
	get(const array<_Tp, _Nm>&& __arr) noexcept
	{
	static_assert(_Int < _Nm, "array index is within bounds");
	return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
	}

	#if __cplusplus > 201703L
	#define __cpp_lib_to_array 201907L

	template<bool _Move = false, typename _Tp, size_t... _Idx>
	constexpr array<remove_cv_t<_Tp>, sizeof...(_Idx)>
	__to_array(_Tp (&__a)[sizeof...(_Idx)], index_sequence<_Idx...>)
	{
	if constexpr (_Move)
	return {{std::move(__a[_Idx])...}};
	else
	return {{__a[_Idx]...}};
	}

	template<typename _Tp, size_t _Nm>
	constexpr array<remove_cv_t<_Tp>, _Nm>
	to_array(_Tp (&__a)[_Nm])
	noexcept(is_nothrow_constructible_v<_Tp, _Tp&>)
	{
	static_assert(!is_array_v<_Tp>);
	static_assert(is_constructible_v<_Tp, _Tp&>);
	if constexpr (is_constructible_v<_Tp, _Tp&>)
	return _GLIBCXX_STD_C::__to_array(__a, make_index_sequence<_Nm>{});
	__builtin_unreachable(); // FIXME: see PR c++/91388
	}

	template<typename _Tp, size_t _Nm>
	constexpr array<remove_cv_t<_Tp>, _Nm>
	to_array(_Tp (&&__a)[_Nm])
	noexcept(is_nothrow_move_constructible_v<_Tp>)
	{
	static_assert(!is_array_v<_Tp>);
	static_assert(is_move_constructible_v<_Tp>);
	if constexpr (is_move_constructible_v<_Tp>)
	return _GLIBCXX_STD_C::__to_array<1>(__a, make_index_sequence<_Nm>{});
	__builtin_unreachable(); // FIXME: see PR c++/91388
	}
	#endif // C++20

	_GLIBCXX_END_NAMESPACE_CONTAINER
	} // namespace std

	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION

	// Tuple interface to class template array.

	/// tuple_size
	template<typename _Tp>
	struct tuple_size;

	/// Partial specialization for std::array
	template<typename _Tp, std::size_t _Nm>
	struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
	: public integral_constant<std::size_t, _Nm> { };

	/// tuple_element
	template<std::size_t _Int, typename _Tp>
	struct tuple_element;

	/// Partial specialization for std::array
	template<std::size_t _Int, typename _Tp, std::size_t _Nm>
	struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
	{
	static_assert(_Int < _Nm, "index is out of bounds");
	typedef _Tp type;
	};

	template<typename _Tp, std::size_t _Nm>
	struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
	{ };

	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace std

	#ifdef _GLIBCXX_DEBUG
	# include <debug/array>
	#endif

	#endif // C++11

	#endif // _GLIBCXX_ARRAY