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Diffstat (limited to 'libcxx/include/__algorithm/partial_sort.h')
-rw-r--r-- | libcxx/include/__algorithm/partial_sort.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/libcxx/include/__algorithm/partial_sort.h b/libcxx/include/__algorithm/partial_sort.h new file mode 100644 index 000000000000..4f9872c4922b --- /dev/null +++ b/libcxx/include/__algorithm/partial_sort.h @@ -0,0 +1,71 @@ +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef _LIBCPP___ALGORITHM_PARTIAL_SORT_H +#define _LIBCPP___ALGORITHM_PARTIAL_SORT_H + +#include <__config> +#include <__algorithm/comp.h> +#include <__algorithm/comp_ref_type.h> +#include <__algorithm/make_heap.h> +#include <__algorithm/sift_down.h> +#include <__algorithm/sort_heap.h> +#include <__iterator/iterator_traits.h> +#include <__utility/swap.h> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +template <class _Compare, class _RandomAccessIterator> +_LIBCPP_CONSTEXPR_AFTER_CXX17 void +__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, + _Compare __comp) +{ + _VSTD::__make_heap<_Compare>(__first, __middle, __comp); + typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first; + for (_RandomAccessIterator __i = __middle; __i != __last; ++__i) + { + if (__comp(*__i, *__first)) + { + swap(*__i, *__first); + _VSTD::__sift_down<_Compare>(__first, __middle, __comp, __len, __first); + } + } + _VSTD::__sort_heap<_Compare>(__first, __middle, __comp); +} + +template <class _RandomAccessIterator, class _Compare> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 +void +partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last, + _Compare __comp) +{ + typedef typename __comp_ref_type<_Compare>::type _Comp_ref; + _VSTD::__partial_sort<_Comp_ref>(__first, __middle, __last, __comp); +} + +template <class _RandomAccessIterator> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 +void +partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last) +{ + _VSTD::partial_sort(__first, __middle, __last, + __less<typename iterator_traits<_RandomAccessIterator>::value_type>()); +} + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___ALGORITHM_PARTIAL_SORT_H |