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author | Devtools Arcadia <arcadia-devtools@yandex-team.ru> | 2022-02-07 18:08:42 +0300 |
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committer | Devtools Arcadia <arcadia-devtools@mous.vla.yp-c.yandex.net> | 2022-02-07 18:08:42 +0300 |
commit | 1110808a9d39d4b808aef724c861a2e1a38d2a69 (patch) | |
tree | e26c9fed0de5d9873cce7e00bc214573dc2195b7 /contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h | |
download | ydb-1110808a9d39d4b808aef724c861a2e1a38d2a69.tar.gz |
intermediate changes
ref:cde9a383711a11544ce7e107a78147fb96cc4029
Diffstat (limited to 'contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h')
-rw-r--r-- | contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h b/contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h new file mode 100644 index 00000000000..95ac2199fd3 --- /dev/null +++ b/contrib/libs/cxxsupp/libcxx/include/__algorithm/find_end.h @@ -0,0 +1,148 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// 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_FIND_END_OF_H +#define _LIBCPP___ALGORITHM_FIND_END_OF_H + +#include <__config> +#include <__algorithm/comp.h> +#include <__iterator/iterator_traits.h> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_BEGIN_NAMESPACE_STD + +template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2> +_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, + _ForwardIterator2 __first2, _ForwardIterator2 __last2, + _BinaryPredicate __pred, forward_iterator_tag, + forward_iterator_tag) { + // modeled after search algorithm + _ForwardIterator1 __r = __last1; // __last1 is the "default" answer + if (__first2 == __last2) + return __r; + while (true) { + while (true) { + if (__first1 == __last1) // if source exhausted return last correct answer + return __r; // (or __last1 if never found) + if (__pred(*__first1, *__first2)) + break; + ++__first1; + } + // *__first1 matches *__first2, now match elements after here + _ForwardIterator1 __m1 = __first1; + _ForwardIterator2 __m2 = __first2; + while (true) { + if (++__m2 == __last2) { // Pattern exhaused, record answer and search for another one + __r = __first1; + ++__first1; + break; + } + if (++__m1 == __last1) // Source exhausted, return last answer + return __r; + if (!__pred(*__m1, *__m2)) // mismatch, restart with a new __first + { + ++__first1; + break; + } // else there is a match, check next elements + } + } +} + +template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2> +_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1 __find_end( + _BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1, _BidirectionalIterator2 __first2, + _BidirectionalIterator2 __last2, _BinaryPredicate __pred, bidirectional_iterator_tag, bidirectional_iterator_tag) { + // modeled after search algorithm (in reverse) + if (__first2 == __last2) + return __last1; // Everything matches an empty sequence + _BidirectionalIterator1 __l1 = __last1; + _BidirectionalIterator2 __l2 = __last2; + --__l2; + while (true) { + // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks + while (true) { + if (__first1 == __l1) // return __last1 if no element matches *__first2 + return __last1; + if (__pred(*--__l1, *__l2)) + break; + } + // *__l1 matches *__l2, now match elements before here + _BidirectionalIterator1 __m1 = __l1; + _BidirectionalIterator2 __m2 = __l2; + while (true) { + if (__m2 == __first2) // If pattern exhausted, __m1 is the answer (works for 1 element pattern) + return __m1; + if (__m1 == __first1) // Otherwise if source exhaused, pattern not found + return __last1; + if (!__pred(*--__m1, *--__m2)) // if there is a mismatch, restart with a new __l1 + { + break; + } // else there is a match, check next elements + } + } +} + +template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2> +_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1 __find_end( + _RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2, + _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag, random_access_iterator_tag) { + // Take advantage of knowing source and pattern lengths. Stop short when source is smaller than pattern + typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2; + if (__len2 == 0) + return __last1; + typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1; + if (__len1 < __len2) + return __last1; + const _RandomAccessIterator1 __s = __first1 + (__len2 - 1); // End of pattern match can't go before here + _RandomAccessIterator1 __l1 = __last1; + _RandomAccessIterator2 __l2 = __last2; + --__l2; + while (true) { + while (true) { + if (__s == __l1) + return __last1; + if (__pred(*--__l1, *__l2)) + break; + } + _RandomAccessIterator1 __m1 = __l1; + _RandomAccessIterator2 __m2 = __l2; + while (true) { + if (__m2 == __first2) + return __m1; + // no need to check range on __m1 because __s guarantees we have enough source + if (!__pred(*--__m1, *--__m2)) { + break; + } + } + } +} + +template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate> +_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 +find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2, + _BinaryPredicate __pred) { + return _VSTD::__find_end<_BinaryPredicate&>( + __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_ForwardIterator1>::iterator_category(), + typename iterator_traits<_ForwardIterator2>::iterator_category()); +} + +template <class _ForwardIterator1, class _ForwardIterator2> +_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 +find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) { + typedef typename iterator_traits<_ForwardIterator1>::value_type __v1; + typedef typename iterator_traits<_ForwardIterator2>::value_type __v2; + return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>()); +} + +_LIBCPP_END_NAMESPACE_STD + +#endif // _LIBCPP___ALGORITHM_FIND_END_OF_H |