Upgrade to 2022-era LLVM LIBCXX

third_party/libcxx/__algorithm/ranges_search.h

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+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_SEARCH_H
+#define _LIBCPP___ALGORITHM_RANGES_SEARCH_H
+
+#include <__algorithm/iterator_operations.h>
+#include <__algorithm/search.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/advance.h>
+#include <__iterator/concepts.h>
+#include <__iterator/distance.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/size.h>
+#include <__ranges/subrange.h>
+#include <__utility/pair.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER >= 20
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __search {
+struct __fn {
+  template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
+  _LIBCPP_HIDE_FROM_ABI static constexpr subrange<_Iter1> __ranges_search_impl(
+      _Iter1 __first1,
+      _Sent1 __last1,
+      _Iter2 __first2,
+      _Sent2 __last2,
+      _Pred& __pred,
+      _Proj1& __proj1,
+      _Proj2& __proj2) {
+    if constexpr (sized_sentinel_for<_Sent2, _Iter2>) {
+      auto __size2 = ranges::distance(__first2, __last2);
+      if (__size2 == 0)
+        return {__first1, __first1};
+
+      if constexpr (sized_sentinel_for<_Sent1, _Iter1>) {
+        auto __size1 = ranges::distance(__first1, __last1);
+        if (__size1 < __size2) {
+          ranges::advance(__first1, __last1);
+          return {__first1, __first1};
+        }
+
+        if constexpr (random_access_iterator<_Iter1> && random_access_iterator<_Iter2>) {
+          auto __ret = std::__search_random_access_impl<_RangeAlgPolicy>(
+              __first1, __last1, __first2, __last2, __pred, __proj1, __proj2, __size1, __size2);
+          return {__ret.first, __ret.second};
+        }
+      }
+    }
+
+    auto __ret =
+        std::__search_forward_impl<_RangeAlgPolicy>(__first1, __last1, __first2, __last2, __pred, __proj1, __proj2);
+    return {__ret.first, __ret.second};
+  }
+
+  template <forward_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+            forward_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
+  subrange<_Iter1> operator()(_Iter1 __first1, _Sent1 __last1,
+                              _Iter2 __first2, _Sent2 __last2,
+                              _Pred __pred = {},
+                              _Proj1 __proj1 = {},
+                              _Proj2 __proj2 = {}) const {
+    return __ranges_search_impl(__first1, __last1, __first2, __last2, __pred, __proj1, __proj2);
+  }
+
+  template <forward_range _Range1,
+            forward_range _Range2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_subrange_t<_Range1> operator()(_Range1&& __range1,
+                                          _Range2&& __range2,
+                                          _Pred __pred = {},
+                                          _Proj1 __proj1 = {},
+                                          _Proj2 __proj2 = {}) const {
+    auto __first1 = ranges::begin(__range1);
+    if constexpr (sized_range<_Range2>) {
+      auto __size2 = ranges::size(__range2);
+      if (__size2 == 0)
+        return {__first1, __first1};
+      if constexpr (sized_range<_Range1>) {
+        auto __size1 = ranges::size(__range1);
+        if (__size1 < __size2) {
+          ranges::advance(__first1, ranges::end(__range1));
+          return {__first1, __first1};
+        }
+      }
+    }
+
+    return __ranges_search_impl(
+        ranges::begin(__range1),
+        ranges::end(__range1),
+        ranges::begin(__range2),
+        ranges::end(__range2),
+        __pred,
+        __proj1,
+        __proj2);
+  }
+
+};
+} // namespace __search
+
+inline namespace __cpo {
+  inline constexpr auto search = __search::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER >= 20
+
+#endif // _LIBCPP___ALGORITHM_RANGES_SEARCH_H