xref: /freebsd-src/contrib/llvm-project/libcxx/include/__algorithm/ranges_min_element.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
181ad6265SDimitry Andric //===----------------------------------------------------------------------===//
281ad6265SDimitry Andric //
381ad6265SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
481ad6265SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
581ad6265SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
681ad6265SDimitry Andric //
781ad6265SDimitry Andric //===----------------------------------------------------------------------===//
881ad6265SDimitry Andric 
981ad6265SDimitry Andric #ifndef _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H
1081ad6265SDimitry Andric #define _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H
1181ad6265SDimitry Andric 
1281ad6265SDimitry Andric #include <__config>
1381ad6265SDimitry Andric #include <__functional/identity.h>
1481ad6265SDimitry Andric #include <__functional/invoke.h>
1581ad6265SDimitry Andric #include <__functional/ranges_operations.h>
1681ad6265SDimitry Andric #include <__iterator/concepts.h>
1781ad6265SDimitry Andric #include <__iterator/projected.h>
1881ad6265SDimitry Andric #include <__ranges/access.h>
1981ad6265SDimitry Andric #include <__ranges/concepts.h>
2081ad6265SDimitry Andric #include <__ranges/dangling.h>
2181ad6265SDimitry Andric #include <__utility/forward.h>
2281ad6265SDimitry Andric 
2381ad6265SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
2481ad6265SDimitry Andric #  pragma GCC system_header
2581ad6265SDimitry Andric #endif
2681ad6265SDimitry Andric 
27b3edf446SDimitry Andric _LIBCPP_PUSH_MACROS
28b3edf446SDimitry Andric #include <__undef_macros>
29b3edf446SDimitry Andric 
3006c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
3181ad6265SDimitry Andric 
3281ad6265SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
3381ad6265SDimitry Andric 
3481ad6265SDimitry Andric namespace ranges {
3581ad6265SDimitry Andric 
36fcaf7f86SDimitry Andric // TODO(ranges): `ranges::min_element` can now simply delegate to `std::__min_element`.
3781ad6265SDimitry Andric template <class _Ip, class _Sp, class _Proj, class _Comp>
3806c3fb27SDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr _Ip __min_element_impl(_Ip __first, _Sp __last, _Comp& __comp, _Proj& __proj) {
3981ad6265SDimitry Andric   if (__first == __last)
4081ad6265SDimitry Andric     return __first;
4181ad6265SDimitry Andric 
4281ad6265SDimitry Andric   _Ip __i = __first;
4381ad6265SDimitry Andric   while (++__i != __last)
4481ad6265SDimitry Andric     if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first)))
4581ad6265SDimitry Andric       __first = __i;
4681ad6265SDimitry Andric   return __first;
4781ad6265SDimitry Andric }
4881ad6265SDimitry Andric 
4981ad6265SDimitry Andric namespace __min_element {
5081ad6265SDimitry Andric struct __fn {
5106c3fb27SDimitry Andric   template <forward_iterator _Ip,
5206c3fb27SDimitry Andric             sentinel_for<_Ip> _Sp,
5306c3fb27SDimitry Andric             class _Proj                                             = identity,
5481ad6265SDimitry Andric             indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less>
55*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Ip
5606c3fb27SDimitry Andric   operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const {
5781ad6265SDimitry Andric     return ranges::__min_element_impl(__first, __last, __comp, __proj);
5881ad6265SDimitry Andric   }
5981ad6265SDimitry Andric 
6006c3fb27SDimitry Andric   template <forward_range _Rp,
6106c3fb27SDimitry Andric             class _Proj                                                         = identity,
6281ad6265SDimitry Andric             indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
63*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Rp>
6406c3fb27SDimitry Andric   operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
6581ad6265SDimitry Andric     return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj);
6681ad6265SDimitry Andric   }
6781ad6265SDimitry Andric };
6881ad6265SDimitry Andric } // namespace __min_element
6981ad6265SDimitry Andric 
7081ad6265SDimitry Andric inline namespace __cpo {
7181ad6265SDimitry Andric inline constexpr auto min_element = __min_element::__fn{};
7281ad6265SDimitry Andric } // namespace __cpo
7381ad6265SDimitry Andric } // namespace ranges
7481ad6265SDimitry Andric 
7581ad6265SDimitry Andric _LIBCPP_END_NAMESPACE_STD
7681ad6265SDimitry Andric 
7706c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
7881ad6265SDimitry Andric 
79b3edf446SDimitry Andric _LIBCPP_POP_MACROS
80b3edf446SDimitry Andric 
8181ad6265SDimitry Andric #endif // _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H
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