1// -*- C++ -*-
 2//===----------------------------------------------------------------------===//
 3//
 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 5// See https://llvm.org/LICENSE.txt for license information.
 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 7//
 8//===----------------------------------------------------------------------===//
 9
10#ifndef _LIBCPP___RANGES_ALL_H
11#define _LIBCPP___RANGES_ALL_H
12
13#include <__config>
14#include <__functional/compose.h>         // TODO(modules): Those should not be required
15#include <__functional/perfect_forward.h> //
16#include <__iterator/concepts.h>
17#include <__iterator/iterator_traits.h>
18#include <__ranges/access.h>
19#include <__ranges/concepts.h>
20#include <__ranges/owning_view.h>
21#include <__ranges/range_adaptor.h>
22#include <__ranges/ref_view.h>
23#include <__type_traits/decay.h>
24#include <__utility/auto_cast.h>
25#include <__utility/declval.h>
26#include <__utility/forward.h>
27
28#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
29#  pragma GCC system_header
30#endif
31
32_LIBCPP_BEGIN_NAMESPACE_STD
33
34#if _LIBCPP_STD_VER >= 20
35
36namespace ranges::views {
37
38namespace __all {
39struct __fn : __range_adaptor_closure<__fn> {
40  template <class _Tp>
41    requires ranges::view<decay_t<_Tp>>
42  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const noexcept(
43      noexcept(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t)))) -> decltype(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t))) {
44    return _LIBCPP_AUTO_CAST(std::forward<_Tp>(__t));
45  }
46
47  template <class _Tp>
48    requires(!ranges::view<decay_t<_Tp>>) && requires(_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; }
49  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
50      noexcept(noexcept(ranges::ref_view{std::forward<_Tp>(__t)})) {
51    return ranges::ref_view{std::forward<_Tp>(__t)};
52  }
53
54  template <class _Tp>
55    requires(
56        !ranges::view<decay_t<_Tp>> && !requires(_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; } &&
57        requires(_Tp&& __t) { ranges::owning_view{std::forward<_Tp>(__t)}; })
58  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
59      noexcept(noexcept(ranges::owning_view{std::forward<_Tp>(__t)})) {
60    return ranges::owning_view{std::forward<_Tp>(__t)};
61  }
62};
63} // namespace __all
64
65inline namespace __cpo {
66inline constexpr auto all = __all::__fn{};
67} // namespace __cpo
68
69template <ranges::viewable_range _Range>
70using all_t = decltype(views::all(std::declval<_Range>()));
71
72} // namespace ranges::views
73
74#endif // _LIBCPP_STD_VER >= 20
75
76_LIBCPP_END_NAMESPACE_STD
77
78#endif // _LIBCPP___RANGES_ALL_H