| // -*- 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 <__algorithm/comp.h> |
| #include <__algorithm/iterator_operations.h> |
| #include <__algorithm/search.h> |
| #include <__config> |
| #include <__functional/identity.h> |
| #include <__functional/invoke.h> |
| #include <__iterator/advance.h> |
| #include <__iterator/iterator_traits.h> |
| #include <__iterator/next.h> |
| #include <__iterator/reverse_iterator.h> |
| #include <__utility/pair.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template < |
| class _AlgPolicy, |
| class _Iter1, |
| class _Sent1, |
| class _Iter2, |
| class _Sent2, |
| class _Pred, |
| class _Proj1, |
| class _Proj2> |
| _LIBCPP_HIDE_FROM_ABI inline _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_Iter1, _Iter1> __find_end_impl( |
| _Iter1 __first1, |
| _Sent1 __last1, |
| _Iter2 __first2, |
| _Sent2 __last2, |
| _Pred& __pred, |
| _Proj1& __proj1, |
| _Proj2& __proj2, |
| forward_iterator_tag, |
| forward_iterator_tag) { |
| // modeled after search algorithm |
| _Iter1 __match_first = _IterOps<_AlgPolicy>::next(__first1, __last1); // __last1 is the "default" answer |
| _Iter1 __match_last = __match_first; |
| if (__first2 == __last2) |
| return pair<_Iter1, _Iter1>(__match_last, __match_last); |
| while (true) { |
| while (true) { |
| if (__first1 == __last1) // if source exhausted return last correct answer (or __last1 if never found) |
| return pair<_Iter1, _Iter1>(__match_first, __match_last); |
| if (std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2))) |
| break; |
| ++__first1; |
| } |
| // *__first1 matches *__first2, now match elements after here |
| _Iter1 __m1 = __first1; |
| _Iter2 __m2 = __first2; |
| while (true) { |
| if (++__m2 == __last2) { // Pattern exhaused, record answer and search for another one |
| __match_first = __first1; |
| __match_last = ++__m1; |
| ++__first1; |
| break; |
| } |
| if (++__m1 == __last1) // Source exhausted, return last answer |
| return pair<_Iter1, _Iter1>(__match_first, __match_last); |
| // mismatch, restart with a new __first |
| if (!std::__invoke(__pred, std::__invoke(__proj1, *__m1), std::__invoke(__proj2, *__m2))) |
| { |
| ++__first1; |
| break; |
| } // else there is a match, check next elements |
| } |
| } |
| } |
| |
| template < |
| class _IterOps, |
| class _Pred, |
| class _Iter1, |
| class _Sent1, |
| class _Iter2, |
| class _Sent2, |
| class _Proj1, |
| class _Proj2> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter1 __find_end( |
| _Iter1 __first1, |
| _Sent1 __sent1, |
| _Iter2 __first2, |
| _Sent2 __sent2, |
| _Pred& __pred, |
| _Proj1& __proj1, |
| _Proj2& __proj2, |
| bidirectional_iterator_tag, |
| bidirectional_iterator_tag) { |
| auto __last1 = _IterOps::next(__first1, __sent1); |
| auto __last2 = _IterOps::next(__first2, __sent2); |
| // modeled after search algorithm (in reverse) |
| if (__first2 == __last2) |
| return __last1; // Everything matches an empty sequence |
| _Iter1 __l1 = __last1; |
| _Iter2 __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 (std::__invoke(__pred, std::__invoke(__proj1, *--__l1), std::__invoke(__proj2, *__l2))) |
| break; |
| } |
| // *__l1 matches *__l2, now match elements before here |
| _Iter1 __m1 = __l1; |
| _Iter2 __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 there is a mismatch, restart with a new __l1 |
| if (!std::__invoke(__pred, std::__invoke(__proj1, *--__m1), std::__invoke(__proj2, *--__m2))) |
| { |
| break; |
| } // else there is a match, check next elements |
| } |
| } |
| } |
| |
| template < |
| class _AlgPolicy, |
| class _Pred, |
| class _Iter1, |
| class _Sent1, |
| class _Iter2, |
| class _Sent2, |
| class _Proj1, |
| class _Proj2> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Iter1 __find_end( |
| _Iter1 __first1, |
| _Sent1 __sent1, |
| _Iter2 __first2, |
| _Sent2 __sent2, |
| _Pred& __pred, |
| _Proj1& __proj1, |
| _Proj2& __proj2, |
| random_access_iterator_tag, |
| random_access_iterator_tag) { |
| typedef typename iterator_traits<_Iter1>::difference_type _D1; |
| auto __last1 = _IterOps<_AlgPolicy>::next(__first1, __sent1); |
| auto __last2 = _IterOps<_AlgPolicy>::next(__first2, __sent2); |
| // Take advantage of knowing source and pattern lengths. Stop short when source is smaller than pattern |
| auto __len2 = __last2 - __first2; |
| if (__len2 == 0) |
| return __last1; |
| auto __len1 = __last1 - __first1; |
| if (__len1 < __len2) |
| return __last1; |
| const _Iter1 __s = __first1 + _D1(__len2 - 1); // End of pattern match can't go before here |
| _Iter1 __l1 = __last1; |
| _Iter2 __l2 = __last2; |
| --__l2; |
| while (true) { |
| while (true) { |
| if (__s == __l1) |
| return __last1; |
| if (std::__invoke(__pred, std::__invoke(__proj1, *--__l1), std::__invoke(__proj2, *__l2))) |
| break; |
| } |
| _Iter1 __m1 = __l1; |
| _Iter2 __m2 = __l2; |
| while (true) { |
| if (__m2 == __first2) |
| return __m1; |
| // no need to check range on __m1 because __s guarantees we have enough source |
| if (!std::__invoke(__pred, std::__invoke(__proj1, *--__m1), std::__invoke(*--__m2))) { |
| break; |
| } |
| } |
| } |
| } |
| |
| template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate> |
| _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 |
| _ForwardIterator1 __find_end_classic(_ForwardIterator1 __first1, _ForwardIterator1 __last1, |
| _ForwardIterator2 __first2, _ForwardIterator2 __last2, |
| _BinaryPredicate& __pred) { |
| auto __proj = __identity(); |
| return std::__find_end_impl<_ClassicAlgPolicy>( |
| __first1, |
| __last1, |
| __first2, |
| __last2, |
| __pred, |
| __proj, |
| __proj, |
| typename iterator_traits<_ForwardIterator1>::iterator_category(), |
| typename iterator_traits<_ForwardIterator2>::iterator_category()) |
| .first; |
| } |
| |
| template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate> |
| _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 |
| _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, |
| _ForwardIterator2 __first2, _ForwardIterator2 __last2, |
| _BinaryPredicate __pred) { |
| return std::__find_end_classic(__first1, __last1, __first2, __last2, __pred); |
| } |
| |
| template <class _ForwardIterator1, class _ForwardIterator2> |
| _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 |
| _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, |
| _ForwardIterator2 __first2, _ForwardIterator2 __last2) { |
| return std::find_end(__first1, __last1, __first2, __last2, __equal_to()); |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ALGORITHM_FIND_END_OF_H |
