[rtsan] Remove mkfifoat interceptor (#116997)
[llvm-project.git] / libcxx / include / __cxx03 / __algorithm / ranges_minmax.h
blob8adf1af58551867a272ebda323655c0034b87fe4
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 //===----------------------------------------------------------------------===//
9 #ifndef _LIBCPP___ALGORITHM_RANGES_MINMAX_H
10 #define _LIBCPP___ALGORITHM_RANGES_MINMAX_H
12 #include <__cxx03/__algorithm/min_max_result.h>
13 #include <__cxx03/__algorithm/minmax_element.h>
14 #include <__cxx03/__assert>
15 #include <__cxx03/__concepts/copyable.h>
16 #include <__cxx03/__concepts/same_as.h>
17 #include <__cxx03/__config>
18 #include <__cxx03/__functional/identity.h>
19 #include <__cxx03/__functional/invoke.h>
20 #include <__cxx03/__functional/ranges_operations.h>
21 #include <__cxx03/__iterator/concepts.h>
22 #include <__cxx03/__iterator/next.h>
23 #include <__cxx03/__iterator/projected.h>
24 #include <__cxx03/__ranges/access.h>
25 #include <__cxx03/__ranges/concepts.h>
26 #include <__cxx03/__type_traits/desugars_to.h>
27 #include <__cxx03/__type_traits/is_reference.h>
28 #include <__cxx03/__type_traits/is_trivially_copyable.h>
29 #include <__cxx03/__type_traits/remove_cvref.h>
30 #include <__cxx03/__utility/forward.h>
31 #include <__cxx03/__utility/move.h>
32 #include <__cxx03/__utility/pair.h>
33 #include <__cxx03/initializer_list>
35 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
36 # pragma GCC system_header
37 #endif
39 #if _LIBCPP_STD_VER >= 20
41 _LIBCPP_PUSH_MACROS
42 # include <__cxx03/__undef_macros>
44 _LIBCPP_BEGIN_NAMESPACE_STD
46 namespace ranges {
47 template <class _T1>
48 using minmax_result = min_max_result<_T1>;
50 namespace __minmax {
51 struct __fn {
52 template <class _Type,
53 class _Proj = identity,
54 indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less>
55 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr ranges::minmax_result<const _Type&>
56 operator()(_LIBCPP_LIFETIMEBOUND const _Type& __a,
57 _LIBCPP_LIFETIMEBOUND const _Type& __b,
58 _Comp __comp = {},
59 _Proj __proj = {}) const {
60 if (std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)))
61 return {__b, __a};
62 return {__a, __b};
65 template <copyable _Type,
66 class _Proj = identity,
67 indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less>
68 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr ranges::minmax_result<_Type>
69 operator()(initializer_list<_Type> __il, _Comp __comp = {}, _Proj __proj = {}) const {
70 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
71 __il.begin() != __il.end(), "initializer_list has to contain at least one element");
72 auto __iters = std::__minmax_element_impl(__il.begin(), __il.end(), __comp, __proj);
73 return ranges::minmax_result<_Type>{*__iters.first, *__iters.second};
76 template <input_range _Range,
77 class _Proj = identity,
78 indirect_strict_weak_order<projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
79 requires indirectly_copyable_storable<iterator_t<_Range>, range_value_t<_Range>*>
80 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr ranges::minmax_result<range_value_t<_Range>>
81 operator()(_Range&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
82 auto __first = ranges::begin(__r);
83 auto __last = ranges::end(__r);
84 using _ValueT = range_value_t<_Range>;
86 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__first != __last, "range has to contain at least one element");
88 // This optimiation is not in minmax_element because clang doesn't see through the pointers and as a result doesn't
89 // vectorize the code.
90 if constexpr (contiguous_range<_Range> && is_integral_v<_ValueT> &&
91 __is_cheap_to_copy<_ValueT> & __is_identity<_Proj>::value &&
92 __desugars_to_v<__less_tag, _Comp, _ValueT, _ValueT>) {
93 minmax_result<_ValueT> __result = {__r[0], __r[0]};
94 for (auto __e : __r) {
95 if (__e < __result.min)
96 __result.min = __e;
97 if (__result.max < __e)
98 __result.max = __e;
100 return __result;
101 } else if constexpr (forward_range<_Range>) {
102 // Special-case the one element case. Avoid repeatedly initializing objects from the result of an iterator
103 // dereference when doing so might not be idempotent. The `if constexpr` avoids the extra branch in cases where
104 // it's not needed.
105 if constexpr (!same_as<remove_cvref_t<range_reference_t<_Range>>, _ValueT> ||
106 is_rvalue_reference_v<range_reference_t<_Range>>) {
107 if (ranges::next(__first) == __last) {
108 // During initialization, members are allowed to refer to already initialized members
109 // (see http://eel.is/c++draft/dcl.init.aggr#6)
110 minmax_result<_ValueT> __result = {*__first, __result.min};
111 return __result;
114 auto __result = std::__minmax_element_impl(__first, __last, __comp, __proj);
115 return {*__result.first, *__result.second};
116 } else {
117 // input_iterators can't be copied, so the implementation for input_iterators has to store
118 // the values instead of a pointer to the correct values
119 auto __less = [&](auto&& __a, auto&& __b) -> bool {
120 return std::invoke(__comp,
121 std::invoke(__proj, std::forward<decltype(__a)>(__a)),
122 std::invoke(__proj, std::forward<decltype(__b)>(__b)));
125 // During initialization, members are allowed to refer to already initialized members
126 // (see http://eel.is/c++draft/dcl.init.aggr#6)
127 ranges::minmax_result<_ValueT> __result = {*__first, __result.min};
128 if (__first == __last || ++__first == __last)
129 return __result;
131 if (__less(*__first, __result.min))
132 __result.min = *__first;
133 else
134 __result.max = *__first;
136 while (++__first != __last) {
137 _ValueT __i = *__first;
138 if (++__first == __last) {
139 if (__less(__i, __result.min))
140 __result.min = __i;
141 else if (!__less(__i, __result.max))
142 __result.max = __i;
143 return __result;
146 if (__less(*__first, __i)) {
147 if (__less(*__first, __result.min))
148 __result.min = *__first;
149 if (!__less(__i, __result.max))
150 __result.max = std::move(__i);
151 } else {
152 if (__less(__i, __result.min))
153 __result.min = std::move(__i);
154 if (!__less(*__first, __result.max))
155 __result.max = *__first;
158 return __result;
162 } // namespace __minmax
164 inline namespace __cpo {
165 inline constexpr auto minmax = __minmax::__fn{};
166 } // namespace __cpo
167 } // namespace ranges
169 _LIBCPP_END_NAMESPACE_STD
171 _LIBCPP_POP_MACROS
173 #endif // _LIBCPP_STD_VER >= 20
175 #endif // _LIBCPP___ALGORITHM_RANGES_MINMAX_H