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Diffstat (limited to 'contrib/llvm-project/libcxx/include/__algorithm/search.h')
| -rw-r--r-- | contrib/llvm-project/libcxx/include/__algorithm/search.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__algorithm/search.h b/contrib/llvm-project/libcxx/include/__algorithm/search.h new file mode 100644 index 000000000000..93771be39e35 --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__algorithm/search.h @@ -0,0 +1,201 @@ +// -*- 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_SEARCH_H +#define _LIBCPP___ALGORITHM_SEARCH_H + +#include <__algorithm/comp.h> +#include <__algorithm/iterator_operations.h> +#include <__config> +#include <__functional/identity.h> +#include <__iterator/advance.h> +#include <__iterator/concepts.h> +#include <__iterator/iterator_traits.h> +#include <__type_traits/is_callable.h> +#include <__utility/pair.h> +#include <type_traits> + +#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 _LIBCPP_CONSTEXPR_SINCE_CXX14 +pair<_Iter1, _Iter1> __search_forward_impl(_Iter1 __first1, _Sent1 __last1, + _Iter2 __first2, _Sent2 __last2, + _Pred& __pred, + _Proj1& __proj1, + _Proj2& __proj2) { + if (__first2 == __last2) + return std::make_pair(__first1, __first1); // Everything matches an empty sequence + while (true) { + // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks + while (true) { + if (__first1 == __last1) { // return __last1 if no element matches *__first2 + _IterOps<_AlgPolicy>::__advance_to(__first1, __last1); + return std::make_pair(__first1, __first1); + } + 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) // If pattern exhausted, __first1 is the answer (works for 1 element pattern) + return std::make_pair(__first1, ++__m1); + if (++__m1 == __last1) { // Otherwise if source exhaused, pattern not found + return std::make_pair(__m1, __m1); + } + + // if there is a mismatch, restart with a new __first1 + if (!std::__invoke(__pred, std::__invoke(__proj1, *__m1), std::__invoke(__proj2, *__m2))) + { + ++__first1; + break; + } // else there is a match, check next elements + } + } +} + +template <class _AlgPolicy, + class _Iter1, class _Sent1, + class _Iter2, class _Sent2, + class _Pred, + class _Proj1, + class _Proj2, + class _DiffT1, + class _DiffT2> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 +pair<_Iter1, _Iter1> __search_random_access_impl(_Iter1 __first1, _Sent1 __last1, + _Iter2 __first2, _Sent2 __last2, + _Pred& __pred, + _Proj1& __proj1, + _Proj2& __proj2, + _DiffT1 __size1, + _DiffT2 __size2) { + const _Iter1 __s = __first1 + __size1 - _DiffT1(__size2 - 1); // Start of pattern match can't go beyond here + + while (true) { + while (true) { + if (__first1 == __s) { + _IterOps<_AlgPolicy>::__advance_to(__first1, __last1); + return std::make_pair(__first1, __first1); + } + if (std::__invoke(__pred, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2))) + break; + ++__first1; + } + + _Iter1 __m1 = __first1; + _Iter2 __m2 = __first2; + while (true) { + if (++__m2 == __last2) + return std::make_pair(__first1, __first1 + _DiffT1(__size2)); + ++__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(__proj2, *__m2))) { + ++__first1; + break; + } + } + } +} + +template <class _Iter1, class _Sent1, + class _Iter2, class _Sent2, + class _Pred, + class _Proj1, + class _Proj2> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 +pair<_Iter1, _Iter1> __search_impl(_Iter1 __first1, _Sent1 __last1, + _Iter2 __first2, _Sent2 __last2, + _Pred& __pred, + _Proj1& __proj1, + _Proj2& __proj2, + __enable_if_t<__is_cpp17_random_access_iterator<_Iter1>::value + && __is_cpp17_random_access_iterator<_Iter2>::value>* = nullptr) { + + auto __size2 = __last2 - __first2; + if (__size2 == 0) + return std::make_pair(__first1, __first1); + + auto __size1 = __last1 - __first1; + if (__size1 < __size2) { + return std::make_pair(__last1, __last1); + } + + return std::__search_random_access_impl<_ClassicAlgPolicy>(__first1, __last1, + __first2, __last2, + __pred, + __proj1, + __proj2, + __size1, + __size2); +} + +template <class _Iter1, class _Sent1, + class _Iter2, class _Sent2, + class _Pred, + class _Proj1, + class _Proj2> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 +pair<_Iter1, _Iter1> __search_impl(_Iter1 __first1, _Sent1 __last1, + _Iter2 __first2, _Sent2 __last2, + _Pred& __pred, + _Proj1& __proj1, + _Proj2& __proj2, + __enable_if_t<__is_cpp17_forward_iterator<_Iter1>::value + && __is_cpp17_forward_iterator<_Iter2>::value + && !(__is_cpp17_random_access_iterator<_Iter1>::value + && __is_cpp17_random_access_iterator<_Iter2>::value)>* = nullptr) { + return std::__search_forward_impl<_ClassicAlgPolicy>(__first1, __last1, + __first2, __last2, + __pred, + __proj1, + __proj2); +} + +template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate> +_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 +_ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, + _ForwardIterator2 __first2, _ForwardIterator2 __last2, + _BinaryPredicate __pred) { + static_assert(__is_callable<_BinaryPredicate, decltype(*__first1), decltype(*__first2)>::value, + "BinaryPredicate has to be callable"); + auto __proj = __identity(); + return std::__search_impl(__first1, __last1, __first2, __last2, __pred, __proj, __proj).first; +} + +template <class _ForwardIterator1, class _ForwardIterator2> +_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 +_ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, + _ForwardIterator2 __first2, _ForwardIterator2 __last2) { + return std::search(__first1, __last1, __first2, __last2, __equal_to()); +} + +#if _LIBCPP_STD_VER > 14 +template <class _ForwardIterator, class _Searcher> +_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator +search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher& __s) { + return __s(__f, __l).first; +} + +#endif + +_LIBCPP_END_NAMESPACE_STD + +#endif // _LIBCPP___ALGORITHM_SEARCH_H |