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_PARTIAL_SORT_COPY_H 10 #define _LIBCPP___ALGORITHM_PARTIAL_SORT_COPY_H 11 12 #include <__algorithm/comp.h> 13 #include <__algorithm/comp_ref_type.h> 14 #include <__algorithm/iterator_operations.h> 15 #include <__algorithm/make_heap.h> 16 #include <__algorithm/make_projected.h> 17 #include <__algorithm/sift_down.h> 18 #include <__algorithm/sort_heap.h> 19 #include <__config> 20 #include <__functional/identity.h> 21 #include <__functional/invoke.h> 22 #include <__iterator/iterator_traits.h> 23 #include <__type_traits/is_callable.h> 24 #include <__utility/move.h> 25 #include <__utility/pair.h> 26 27 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 28 # pragma GCC system_header 29 #endif 30 31 _LIBCPP_BEGIN_NAMESPACE_STD 32 33 template <class _AlgPolicy, class _Compare, 34 class _InputIterator, class _Sentinel1, class _RandomAccessIterator, class _Sentinel2, 35 class _Proj1, class _Proj2> 36 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InputIterator, _RandomAccessIterator> 37 __partial_sort_copy(_InputIterator __first, _Sentinel1 __last, 38 _RandomAccessIterator __result_first, _Sentinel2 __result_last, 39 _Compare&& __comp, _Proj1&& __proj1, _Proj2&& __proj2) 40 { 41 _RandomAccessIterator __r = __result_first; 42 auto&& __projected_comp = std::__make_projected(__comp, __proj2); 43 44 if (__r != __result_last) 45 { 46 for (; __first != __last && __r != __result_last; ++__first, (void) ++__r) 47 *__r = *__first; 48 std::__make_heap<_AlgPolicy>(__result_first, __r, __projected_comp); 49 typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first; 50 for (; __first != __last; ++__first) 51 if (std::__invoke(__comp, std::__invoke(__proj1, *__first), std::__invoke(__proj2, *__result_first))) { 52 *__result_first = *__first; 53 std::__sift_down<_AlgPolicy>(__result_first, __projected_comp, __len, __result_first); 54 } 55 std::__sort_heap<_AlgPolicy>(__result_first, __r, __projected_comp); 56 } 57 58 return pair<_InputIterator, _RandomAccessIterator>( 59 _IterOps<_AlgPolicy>::next(std::move(__first), std::move(__last)), std::move(__r)); 60 } 61 62 template <class _InputIterator, class _RandomAccessIterator, class _Compare> 63 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 64 _RandomAccessIterator 65 partial_sort_copy(_InputIterator __first, _InputIterator __last, 66 _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp) 67 { 68 static_assert(__is_callable<_Compare, decltype(*__first), decltype(*__result_first)>::value, 69 "Comparator has to be callable"); 70 71 auto __result = std::__partial_sort_copy<_ClassicAlgPolicy>(__first, __last, __result_first, __result_last, 72 static_cast<__comp_ref_type<_Compare> >(__comp), __identity(), __identity()); 73 return __result.second; 74 } 75 76 template <class _InputIterator, class _RandomAccessIterator> 77 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 78 _RandomAccessIterator 79 partial_sort_copy(_InputIterator __first, _InputIterator __last, 80 _RandomAccessIterator __result_first, _RandomAccessIterator __result_last) 81 { 82 return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last, __less<>()); 83 } 84 85 _LIBCPP_END_NAMESPACE_STD 86 87 #endif // _LIBCPP___ALGORITHM_PARTIAL_SORT_COPY_H 88