1753f127fSDimitry Andric //===----------------------------------------------------------------------===// 2753f127fSDimitry Andric // 3753f127fSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4753f127fSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5753f127fSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6753f127fSDimitry Andric // 7753f127fSDimitry Andric //===----------------------------------------------------------------------===// 8753f127fSDimitry Andric 9753f127fSDimitry Andric #ifndef _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H 10753f127fSDimitry Andric #define _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H 11753f127fSDimitry Andric 12fcaf7f86SDimitry Andric #include <__algorithm/iterator_operations.h> 13753f127fSDimitry Andric #include <__algorithm/make_projected.h> 14753f127fSDimitry Andric #include <__algorithm/nth_element.h> 15753f127fSDimitry Andric #include <__config> 16753f127fSDimitry Andric #include <__functional/identity.h> 17753f127fSDimitry Andric #include <__functional/invoke.h> 18753f127fSDimitry Andric #include <__functional/ranges_operations.h> 19753f127fSDimitry Andric #include <__iterator/concepts.h> 20753f127fSDimitry Andric #include <__iterator/iterator_traits.h> 21753f127fSDimitry Andric #include <__iterator/next.h> 22753f127fSDimitry Andric #include <__iterator/projected.h> 23753f127fSDimitry Andric #include <__iterator/sortable.h> 24753f127fSDimitry Andric #include <__ranges/access.h> 25753f127fSDimitry Andric #include <__ranges/concepts.h> 26753f127fSDimitry Andric #include <__ranges/dangling.h> 27753f127fSDimitry Andric #include <__utility/forward.h> 28753f127fSDimitry Andric #include <__utility/move.h> 29753f127fSDimitry Andric 30753f127fSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 31753f127fSDimitry Andric # pragma GCC system_header 32753f127fSDimitry Andric #endif 33753f127fSDimitry Andric 34*b3edf446SDimitry Andric _LIBCPP_PUSH_MACROS 35*b3edf446SDimitry Andric #include <__undef_macros> 36*b3edf446SDimitry Andric 3706c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 38753f127fSDimitry Andric 39753f127fSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 40753f127fSDimitry Andric 41753f127fSDimitry Andric namespace ranges { 42753f127fSDimitry Andric namespace __nth_element { 43753f127fSDimitry Andric 44753f127fSDimitry Andric struct __fn { 45753f127fSDimitry Andric template <class _Iter, class _Sent, class _Comp, class _Proj> 4606c3fb27SDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr static _Iter __nth_element_fn_impl__fn4706c3fb27SDimitry Andric __nth_element_fn_impl(_Iter __first, _Iter __nth, _Sent __last, _Comp& __comp, _Proj& __proj) { 48753f127fSDimitry Andric auto __last_iter = ranges::next(__first, __last); 49753f127fSDimitry Andric 5061cfbce3SDimitry Andric auto&& __projected_comp = std::__make_projected(__comp, __proj); 51fcaf7f86SDimitry Andric std::__nth_element_impl<_RangeAlgPolicy>(std::move(__first), std::move(__nth), __last_iter, __projected_comp); 52753f127fSDimitry Andric 53753f127fSDimitry Andric return __last_iter; 54753f127fSDimitry Andric } 55753f127fSDimitry Andric 56753f127fSDimitry Andric template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity> 57753f127fSDimitry Andric requires sortable<_Iter, _Comp, _Proj> 5806c3fb27SDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr _Iter operator__fn5906c3fb27SDimitry Andric operator()(_Iter __first, _Iter __nth, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const { 60753f127fSDimitry Andric return __nth_element_fn_impl(std::move(__first), std::move(__nth), std::move(__last), __comp, __proj); 61753f127fSDimitry Andric } 62753f127fSDimitry Andric 63753f127fSDimitry Andric template <random_access_range _Range, class _Comp = ranges::less, class _Proj = identity> 64753f127fSDimitry Andric requires sortable<iterator_t<_Range>, _Comp, _Proj> 6506c3fb27SDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range> operator__fn6606c3fb27SDimitry Andric operator()(_Range&& __r, iterator_t<_Range> __nth, _Comp __comp = {}, _Proj __proj = {}) const { 67753f127fSDimitry Andric return __nth_element_fn_impl(ranges::begin(__r), std::move(__nth), ranges::end(__r), __comp, __proj); 68753f127fSDimitry Andric } 69753f127fSDimitry Andric }; 70753f127fSDimitry Andric 71753f127fSDimitry Andric } // namespace __nth_element 72753f127fSDimitry Andric 73753f127fSDimitry Andric inline namespace __cpo { 74753f127fSDimitry Andric inline constexpr auto nth_element = __nth_element::__fn{}; 75753f127fSDimitry Andric } // namespace __cpo 76753f127fSDimitry Andric } // namespace ranges 77753f127fSDimitry Andric 78753f127fSDimitry Andric _LIBCPP_END_NAMESPACE_STD 79753f127fSDimitry Andric 8006c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 81753f127fSDimitry Andric 82*b3edf446SDimitry Andric _LIBCPP_POP_MACROS 83*b3edf446SDimitry Andric 84753f127fSDimitry Andric #endif // _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H 85