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/ranges_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 {
39namespace __max {
40struct __fn {
41 template <class _Tp,
42 class _Proj = identity,
43 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
44 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&
45 operator()(_LIBCPP_LIFETIMEBOUND const _Tp& __a,
46 _LIBCPP_LIFETIMEBOUND const _Tp& __b,
47 _Comp __comp = {},
48 _Proj __proj = {}) const {
49 return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a;
50 }
51
52 template <copyable _Tp,
53 class _Proj = identity,
54 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
55 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp
56 operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
57 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
58 __il.begin() != __il.end(), "initializer_list must contain at least one element");
59
60 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool { return std::invoke(__comp, __rhs, __lhs); };
61 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj);
62 }
63
64 template <input_range _Rp,
65 class _Proj = identity,
66 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
67 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
68 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr range_value_t<_Rp>
69 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
70 auto __first = ranges::begin(__r);
71 auto __last = ranges::end(__r);
72
73 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__first != __last, "range must contain at least one element");
74
75 if constexpr (forward_range<_Rp> && !__is_cheap_to_copy<range_value_t<_Rp>>) {
76 auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool {
77 return std::invoke(__comp, __rhs, __lhs);
78 };
79 return *ranges::__min_element_impl(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj);
80 } else {
81 range_value_t<_Rp> __result = *__first;
82 while (++__first != __last) {
83 if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first)))
84 __result = *__first;
85 }
86 return __result;
87 }
88 }
89};
90} // namespace __max
91
92inline namespace __cpo {
93inline constexpr auto max = __max::__fn{};
94} // namespace __cpo
95} // namespace ranges
96
97_LIBCPP_END_NAMESPACE_STD
98
99_LIBCPP_POP_MACROS
100
101#endif // _LIBCPP_STD_VER >= 20
102
103#endif // _LIBCPP___ALGORITHM_RANGES_MAX_H
104