1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___ALGORITHM_RANGES_MAX_H
10#define _LIBCPP___ALGORITHM_RANGES_MAX_H
11
12#include <__algorithm/min_element.h>
13#include <__assert>
14#include <__concepts/copyable.h>
15#include <__config>
16#include <__functional/identity.h>
17#include <__functional/invoke.h>
18#include <__functional/ranges_operations.h>
19#include <__iterator/concepts.h>
20#include <__iterator/projected.h>
21#include <__ranges/access.h>
22#include <__ranges/concepts.h>
23#include <__type_traits/is_trivially_copyable.h>
24#include <__utility/move.h>
25#include <initializer_list>
26
27#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
28# pragma GCC system_header
29#endif
30
31#if _LIBCPP_STD_VER >= 20
32
33_LIBCPP_PUSH_MACROS
34# include <__undef_macros>
35
36_LIBCPP_BEGIN_NAMESPACE_STD
37
38namespace ranges {
39struct __max {
40 template <class _Tp,
41 class _Proj = identity,
42 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
43 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&
44 operator()(_LIBCPP_LIFETIMEBOUND const _Tp& __a,
45 _LIBCPP_LIFETIMEBOUND const _Tp& __b,
46 _Comp __comp = {},
47 _Proj __proj = {}) const {
48 return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a;
49 }
50
51 template <copyable _Tp,
52 class _Proj = identity,
53 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
54 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp
55 operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
56 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
57 __il.begin() != __il.end(), "initializer_list must contain at least one element");
58
59 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool { return std::invoke(__comp, __rhs, __lhs); };
60 return *std::__min_element(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj);
61 }
62
63 template <input_range _Rp,
64 class _Proj = identity,
65 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
66 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
67 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr range_value_t<_Rp>
68 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
69 auto __first = ranges::begin(__r);
70 auto __last = ranges::end(__r);
71
72 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__first != __last, "range must contain at least one element");
73
74 if constexpr (forward_range<_Rp> && !__is_cheap_to_copy<range_value_t<_Rp>>) {
75 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool {
76 return std::invoke(__comp, __rhs, __lhs);
77 };
78 return *std::__min_element(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj);
79 } else {
80 range_value_t<_Rp> __result = *__first;
81 while (++__first != __last) {
82 if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first)))
83 __result = *__first;
84 }
85 return __result;
86 }
87 }
88};
89
90inline namespace __cpo {
91inline constexpr auto max = __max{};
92} // namespace __cpo
93} // namespace ranges
94
95_LIBCPP_END_NAMESPACE_STD
96
97_LIBCPP_POP_MACROS
98
99#endif // _LIBCPP_STD_VER >= 20
100
101#endif // _LIBCPP___ALGORITHM_RANGES_MAX_H
102