xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/ranges_max_element.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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_ELEMENT_H
10 #define _LIBCPP___ALGORITHM_RANGES_MAX_ELEMENT_H
11 
12 #include <__algorithm/ranges_min_element.h>
13 #include <__config>
14 #include <__functional/identity.h>
15 #include <__functional/invoke.h>
16 #include <__functional/ranges_operations.h>
17 #include <__iterator/concepts.h>
18 #include <__iterator/projected.h>
19 #include <__ranges/access.h>
20 #include <__ranges/concepts.h>
21 #include <__ranges/dangling.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29 
30 #if _LIBCPP_STD_VER >= 20
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 namespace __max_element {
36 struct __fn {
37   template <forward_iterator _Ip,
38             sentinel_for<_Ip> _Sp,
39             class _Proj                                             = identity,
40             indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less>
41   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Ip
operator__fn42   operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const {
43     auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool { return std::invoke(__comp, __rhs, __lhs); };
44     return ranges::__min_element_impl(__first, __last, __comp_lhs_rhs_swapped, __proj);
45   }
46 
47   template <forward_range _Rp,
48             class _Proj                                                         = identity,
49             indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
50   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
operator__fn51   operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
52     auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) -> bool { return std::invoke(__comp, __rhs, __lhs); };
53     return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp_lhs_rhs_swapped, __proj);
54   }
55 };
56 } // namespace __max_element
57 
58 inline namespace __cpo {
59 inline constexpr auto max_element = __max_element::__fn{};
60 } // namespace __cpo
61 } // namespace ranges
62 
63 _LIBCPP_END_NAMESPACE_STD
64 
65 #endif // _LIBCPP_STD_VER >= 20
66 
67 _LIBCPP_POP_MACROS
68 
69 #endif // _LIBCPP___ALGORITHM_RANGES_MAX_ELEMENT_H
70