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_MIN_H
10#define _LIBCPP___ALGORITHM_RANGES_MIN_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 <initializer_list>
25
26#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27# pragma GCC system_header
28#endif
29
30#if _LIBCPP_STD_VER >= 20
31
32_LIBCPP_PUSH_MACROS
33# include <__undef_macros>
34
35_LIBCPP_BEGIN_NAMESPACE_STD
36
37namespace ranges {
38namespace __min {
39struct __fn {
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, __b), std::invoke(__proj, __a)) ? __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 return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp, __proj);
59 }
60
61 template <input_range _Rp,
62 class _Proj = identity,
63 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
64 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
65 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr range_value_t<_Rp>
66 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
67 auto __first = ranges::begin(__r);
68 auto __last = ranges::end(__r);
69 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__first != __last, "range must contain at least one element");
70 if constexpr (forward_range<_Rp> && !__is_cheap_to_copy<range_value_t<_Rp>>) {
71 return *ranges::__min_element_impl(__first, __last, __comp, __proj);
72 } else {
73 range_value_t<_Rp> __result = *__first;
74 while (++__first != __last) {
75 if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result)))
76 __result = *__first;
77 }
78 return __result;
79 }
80 }
81};
82} // namespace __min
83
84inline namespace __cpo {
85inline constexpr auto min = __min::__fn{};
86} // namespace __cpo
87} // namespace ranges
88
89_LIBCPP_END_NAMESPACE_STD
90
91_LIBCPP_POP_MACROS
92
93#endif // _LIBCPP_STD_VER >= 20
94
95#endif // _LIBCPP___ALGORITHM_RANGES_MIN_H
96