llvm-project/libcxx/include/__ranges/concepts.h

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// -*- 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_CONCEPTS_H
#define _LIBCPP___RANGES_CONCEPTS_H
#include <__concepts/constructible.h>
#include <__concepts/movable.h>
#include <__concepts/same_as.h>
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/incrementable_traits.h>
#include <__iterator/iter_move.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/readable_traits.h>
#include <__ranges/access.h>
#include <__ranges/data.h>
#include <__ranges/enable_borrowed_range.h>
#include <__ranges/enable_view.h>
#include <__ranges/size.h>
#include <initializer_list>
#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 ranges {
// [range.range]
template <class _Tp>
concept range = requires(_Tp& __t) {
ranges::begin(__t); // sometimes equality-preserving
ranges::end(__t);
};
template<class _Range>
concept borrowed_range = range<_Range> &&
(is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>);
// `iterator_t` defined in <__ranges/access.h>
template <range _Rp>
using sentinel_t = decltype(ranges::end(declval<_Rp&>()));
template <range _Rp>
using range_difference_t = iter_difference_t<iterator_t<_Rp>>;
template <range _Rp>
using range_value_t = iter_value_t<iterator_t<_Rp>>;
template <range _Rp>
using range_reference_t = iter_reference_t<iterator_t<_Rp>>;
template <range _Rp>
using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp>>;
// [range.sized]
template <class _Tp>
concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); };
template<sized_range _Rp>
using range_size_t = decltype(ranges::size(declval<_Rp&>()));
// `disable_sized_range` defined in `<__ranges/size.h>`
// [range.view], views
// `enable_view` defined in <__ranges/enable_view.h>
// `view_base` defined in <__ranges/enable_view.h>
template <class _Tp>
concept view =
range<_Tp> &&
movable<_Tp> &&
enable_view<_Tp>;
template <class _Range>
concept __simple_view =
view<_Range> && range<const _Range> &&
same_as<iterator_t<_Range>, iterator_t<const _Range>> &&
same_as<sentinel_t<_Range>, sentinel_t<const _Range>>;
// [range.refinements], other range refinements
template <class _Rp, class _Tp>
concept output_range = range<_Rp> && output_iterator<iterator_t<_Rp>, _Tp>;
template <class _Tp>
concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>;
template <class _Tp>
concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp>>;
template <class _Tp>
concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>;
template <class _Tp>
concept random_access_range =
bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>;
template<class _Tp>
concept contiguous_range =
random_access_range<_Tp> &&
contiguous_iterator<iterator_t<_Tp>> &&
requires(_Tp& __t) {
{ ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>;
};
template <class _Tp>
concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>;
template <class _Tp>
inline constexpr bool __is_std_initializer_list = false;
template <class _Ep>
inline constexpr bool __is_std_initializer_list<initializer_list<_Ep>> = true;
template <class _Tp>
concept viewable_range =
range<_Tp> &&
((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) ||
(!view<remove_cvref_t<_Tp>> &&
(is_lvalue_reference_v<_Tp> ||
(movable<remove_reference_t<_Tp>> && !__is_std_initializer_list<remove_cvref_t<_Tp>>))));
} // namespace ranges
#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___RANGES_CONCEPTS_H