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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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H10#define _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H11 12#include <__algorithm/iterator_operations.h>13#include <__algorithm/make_projected.h>14#include <__algorithm/nth_element.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/iterator_traits.h>21#include <__iterator/next.h>22#include <__iterator/projected.h>23#include <__iterator/sortable.h>24#include <__ranges/access.h>25#include <__ranges/concepts.h>26#include <__ranges/dangling.h>27#include <__utility/forward.h>28#include <__utility/move.h>29 30#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)31# pragma GCC system_header32#endif33 34_LIBCPP_PUSH_MACROS35#include <__undef_macros>36 37#if _LIBCPP_STD_VER >= 2038 39_LIBCPP_BEGIN_NAMESPACE_STD40 41namespace ranges {42struct __nth_element {43 template <class _Iter, class _Sent, class _Comp, class _Proj>44 _LIBCPP_HIDE_FROM_ABI constexpr static _Iter45 __nth_element_fn_impl(_Iter __first, _Iter __nth, _Sent __last, _Comp& __comp, _Proj& __proj) {46 auto __last_iter = ranges::next(__first, __last);47 48 auto&& __projected_comp = std::__make_projected(__comp, __proj);49 std::__nth_element_impl<_RangeAlgPolicy>(std::move(__first), std::move(__nth), __last_iter, __projected_comp);50 51 return __last_iter;52 }53 54 template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>55 requires sortable<_Iter, _Comp, _Proj>56 _LIBCPP_HIDE_FROM_ABI constexpr _Iter57 operator()(_Iter __first, _Iter __nth, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {58 return __nth_element_fn_impl(std::move(__first), std::move(__nth), std::move(__last), __comp, __proj);59 }60 61 template <random_access_range _Range, class _Comp = ranges::less, class _Proj = identity>62 requires sortable<iterator_t<_Range>, _Comp, _Proj>63 _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range>64 operator()(_Range&& __r, iterator_t<_Range> __nth, _Comp __comp = {}, _Proj __proj = {}) const {65 return __nth_element_fn_impl(ranges::begin(__r), std::move(__nth), ranges::end(__r), __comp, __proj);66 }67};68 69inline namespace __cpo {70inline constexpr auto nth_element = __nth_element{};71} // namespace __cpo72} // namespace ranges73 74_LIBCPP_END_NAMESPACE_STD75 76#endif // _LIBCPP_STD_VER >= 2077 78_LIBCPP_POP_MACROS79 80#endif // _LIBCPP___ALGORITHM_RANGES_NTH_ELEMENT_H81