// -*- 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/enable_if.h>
#include <__type_traits/invoke.h>
#include <__type_traits/is_callable.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 _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,
__enable_if_t<__has_random_access_iterator_category<_Iter1>::value &&
__has_random_access_iterator_category<_Iter2>::value,
int> = 0>
_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) {
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,
__enable_if_t<__has_forward_iterator_category<_Iter1>::value && __has_forward_iterator_category<_Iter2>::value &&
!(__has_random_access_iterator_category<_Iter1>::value &&
__has_random_access_iterator_category<_Iter2>::value),
int> = 0>
_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) {
return std::__search_forward_impl<_ClassicAlgPolicy>(__first1, __last1, __first2, __last2, __pred, __proj1, __proj2);
}
template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _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,
"The comparator has to be callable");
auto __proj = __identity();
return std::__search_impl(__first1, __last1, __first2, __last2, __pred, __proj, __proj).first;
}
template <class _ForwardIterator1, class _ForwardIterator2>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _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 >= 17
template <class _ForwardIterator, class _Searcher>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI _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
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