// -*- 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_RANGES
#define _LIBCPP_RANGES

/*

#include <compare>              // see [compare.syn]
#include <initializer_list>     // see [initializer.list.syn]
#include <iterator>             // see [iterator.synopsis]

namespace std::ranges {
  inline namespace unspecified {
    // [range.access], range access
    inline constexpr unspecified begin = unspecified;
    inline constexpr unspecified end = unspecified;
    inline constexpr unspecified cbegin = unspecified;
    inline constexpr unspecified cend = unspecified;

    inline constexpr unspecified size = unspecified;
    inline constexpr unspecified ssize = unspecified;
  }

  // [range.range], ranges
  template<class T>
    concept range = see below;

  template<class T>
    inline constexpr bool enable_borrowed_range = false;

  template<class T>
    using iterator_t = decltype(ranges::begin(declval<T&>()));
  template<range R>
    using sentinel_t = decltype(ranges::end(declval<R&>()));
  template<range R>
    using range_difference_t = iter_difference_t<iterator_t<R>>;
  template<sized_range R>
    using range_size_t = decltype(ranges::size(declval<R&>()));
  template<range R>
    using range_value_t = iter_value_t<iterator_t<R>>;
  template<range R>
    using range_reference_t = iter_reference_t<iterator_t<R>>;
  template<range R>
    using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<R>>;

  // [range.sized], sized ranges
  template<class>
    inline constexpr bool disable_sized_range = false;

  template<class T>
    concept sized_range = ...;

  // [range.view], views
  template<class T>
    inline constexpr bool enable_view = ...;

  struct view_base { };

  template<class T>
    concept view = ...;

  // [range.refinements], other range refinements
  template<class R, class T>
    concept output_range = see below;

  template<class T>
    concept input_range = see below;

  template<class T>
    concept forward_range = see below;

  template<class T>
  concept bidirectional_range = see below;

  template<class T>
  concept random_access_range = see below;

  template<class T>
  concept contiguous_range = see below;

  template <class _Tp>
    concept common_range = see below;

  template<class T>
  concept viewable_range = see below;

  // [view.interface], class template view_interface
  template<class D>
    requires is_class_v<D> && same_as<D, remove_cv_t<D>>
  class view_interface;

  // [range.subrange], sub-ranges
  enum class subrange_kind : bool { unsized, sized };

  template<input_or_output_iterator I, sentinel_for<I> S = I, subrange_kind K = see below>
    requires (K == subrange_kind::sized || !sized_sentinel_for<S, I>)
  class subrange;

  template<class I, class S, subrange_kind K>
    inline constexpr bool enable_borrowed_range<subrange<I, S, K>> = true;

  // [range.dangling], dangling iterator handling
  struct dangling;

  template<range R>
    using borrowed_iterator_t = see below;

  template<range R>
    using borrowed_subrange_t = see below;

  // [range.empty], empty view
  template<class T>
    requires is_object_v<T>
  class empty_view;

  // [range.all], all view
  namespace views {
    inline constexpr unspecified all = unspecified;

    template<viewable_range R>
      using all_t = decltype(all(declval<R>()));
  }

  template<range R>
    requires is_object_v<R>
  class ref_view;

  template<class T>
    inline constexpr bool enable_borrowed_range<ref_view<T>> = true;

  template<range R>
    requires see below
  class owning_view;

  template<class T>
    inline constexpr bool enable_borrowed_range<owning_view<T>> = enable_borrowed_range<T>;

  // [range.drop], drop view
  template<view V>
    class drop_view;

  template<class T>
    inline constexpr bool enable_borrowed_range<drop_view<T>> = enable_borrowed_range<T>;

  // [range.transform], transform view
  template<input_range V, copy_constructible F>
    requires view<V> && is_object_v<F> &&
             regular_invocable<F&, range_reference_t<V>> &&
             can-reference<invoke_result_t<F&, range_reference_t<V>>>
  class transform_view;

  // [range.counted], counted view
  namespace views { inline constexpr unspecified counted = unspecified; }

  // [range.common], common view
  template<view V>
    requires (!common_range<V> && copyable<iterator_t<V>>)
  class common_view;

 // [range.reverse], reverse view
  template<view V>
    requires bidirectional_range<V>
  class reverse_view;

  template<class T>
    inline constexpr bool enable_borrowed_range<reverse_view<T>> = enable_borrowed_range<T>;

  template<class T>
  inline constexpr bool enable_borrowed_range<common_view<T>> = enable_borrowed_range<T>;

   // [range.take], take view
  template<view> class take_view;

  template<class T>
  inline constexpr bool enable_borrowed_range<take_view<T>> = enable_borrowed_range<T>;

  template<copy_constructible T>
    requires is_object_v<T>
  class single_view;

  template<weakly_incrementable W, semiregular Bound = unreachable_sentinel_t>
    requires weakly-equality-comparable-with<W, Bound> && copyable<W>
  class iota_view;

  template<class W, class Bound>
    inline constexpr bool enable_borrowed_range<iota_view<W, Bound>> = true;

  // [range.join], join view
  template<input_range V>
    requires view<V> && input_range<range_reference_t<V>>
  class join_view;
}

namespace std {
  namespace views = ranges::views;

  template<class T> struct tuple_size;
  template<size_t I, class T> struct tuple_element;

  template<class I, class S, ranges::subrange_kind K>
  struct tuple_size<ranges::subrange<I, S, K>>
    : integral_constant<size_t, 2> {};

  template<class I, class S, ranges::subrange_kind K>
  struct tuple_element<0, ranges::subrange<I, S, K>> {
    using type = I;
  };

  template<class I, class S, ranges::subrange_kind K>
  struct tuple_element<1, ranges::subrange<I, S, K>> {
    using type = S;
  };

  template<class I, class S, ranges::subrange_kind K>
  struct tuple_element<0, const ranges::subrange<I, S, K>> {
    using type = I;
  };

  template<class I, class S, ranges::subrange_kind K>
  struct tuple_element<1, const ranges::subrange<I, S, K>> {
    using type = S;
  };
}
*/

// Make sure all feature-test macros are available.
#include <version>
// Enable the contents of the header only when libc++ was built with LIBCXX_ENABLE_INCOMPLETE_FEATURES.
#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)

#include <__config>
#include <__ranges/access.h>
#include <__ranges/all.h>
#include <__ranges/common_view.h>
#include <__ranges/concepts.h>
#include <__ranges/counted.h>
#include <__ranges/dangling.h>
#include <__ranges/data.h>
#include <__ranges/drop_view.h>
#include <__ranges/empty.h>
#include <__ranges/empty_view.h>
#include <__ranges/enable_borrowed_range.h>
#include <__ranges/enable_view.h>
#include <__ranges/iota_view.h>
#include <__ranges/join_view.h>
#include <__ranges/ref_view.h>
#include <__ranges/reverse_view.h>
#include <__ranges/single_view.h>
#include <__ranges/size.h>
#include <__ranges/subrange.h>
#include <__ranges/take_view.h>
#include <__ranges/transform_view.h>
#include <__ranges/view_interface.h>
#include <compare>          // Required by the standard.
#include <initializer_list> // Required by the standard.
#include <iterator>         // Required by the standard.
#include <type_traits>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#if !defined(_LIBCPP_HAS_NO_CONCEPTS)

namespace views = ranges::views;

#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)

_LIBCPP_END_NAMESPACE_STD

#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)

#endif // _LIBCPP_RANGES