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/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 {
38struct __min {
39 template <class _Tp,
40 class _Proj = identity,
41 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
42 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&
43 operator()(_LIBCPP_LIFETIMEBOUND const _Tp& __a,
44 _LIBCPP_LIFETIMEBOUND const _Tp& __b,
45 _Comp __comp = {},
46 _Proj __proj = {}) const {
47 return std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)) ? __b : __a;
48 }
49
50 template <copyable _Tp,
51 class _Proj = identity,
52 indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
53 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp
54 operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
55 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
56 __il.begin() != __il.end(), "initializer_list must contain at least one element");
57 return *std::__min_element(__il.begin(), __il.end(), __comp, __proj);
58 }
59
60 template <input_range _Rp,
61 class _Proj = identity,
62 indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
63 requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
64 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr range_value_t<_Rp>
65 operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
66 auto __first = ranges::begin(__r);
67 auto __last = ranges::end(__r);
68 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__first != __last, "range must contain at least one element");
69 if constexpr (forward_range<_Rp> && !__is_cheap_to_copy<range_value_t<_Rp>>) {
70 return *std::__min_element(__first, __last, __comp, __proj);
71 } else {
72 range_value_t<_Rp> __result = *__first;
73 while (++__first != __last) {
74 if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result)))
75 __result = *__first;
76 }
77 return __result;
78 }
79 }
80};
81
82inline namespace __cpo {
83inline constexpr auto min = __min{};
84} // namespace __cpo
85} // namespace ranges
86
87_LIBCPP_END_NAMESPACE_STD
88
89_LIBCPP_POP_MACROS
90
91#endif // _LIBCPP_STD_VER >= 20
92
93#endif // _LIBCPP___ALGORITHM_RANGES_MIN_H
94