1 files changed, 101 insertions, 0 deletions
diff --git a/libcxx/include/__algorithm/ranges_find_first_of.h b/libcxx/include/__algorithm/ranges_find_first_of.h
new file mode 100644
index 000000000000..ae31d38e6a95
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+++ b/libcxx/include/__algorithm/ranges_find_first_of.h
@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_FIND_FIRST_OF_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __find_first_of {
+struct __fn {
+
+  template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  _Iter1 __find_first_of_impl(_Iter1 __first1, _Sent1 __last1,
+                              _Iter2 __first2, _Sent2 __last2,
+                              _Pred& __pred,
+                              _Proj1& __proj1,
+                              _Proj2& __proj2) {
+    for (; __first1 != __last1; ++__first1) {
+      for (auto __j = __first2; __j != __last2; ++__j) {
+        if (std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__j)))
+          return __first1;
+      }
+    }
+    return __first1;
+  }
+
+  template <input_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_HIDE_FROM_ABI constexpr
+  _Iter1 operator()(_Iter1 __first1, _Sent1 __last1,
+                    _Iter2 __first2, _Sent2 __last2,
+                    _Pred __pred = {},
+                    _Proj1 __proj1 = {},
+                    _Proj2 __proj2 = {}) const {
+    return __find_first_of_impl(std::move(__first1), std::move(__last1),
+                                std::move(__first2), std::move(__last2),
+                                __pred,
+                                __proj1,
+                                __proj2);
+  }
+
+  template <input_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_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range1> operator()(_Range1&& __range1,
+                                          _Range2&& __range2,
+                                          _Pred __pred = {},
+                                          _Proj1 __proj1 = {},
+                                          _Proj2 __proj2 = {}) const {
+    return __find_first_of_impl(ranges::begin(__range1), ranges::end(__range1),
+                                ranges::begin(__range2), ranges::end(__range2),
+                                __pred,
+                                __proj1,
+                                __proj2);
+  }
+
+};
+} // namespace __find_first_of
+
+inline namespace __cpo {
+  inline constexpr auto find_first_of = __find_first_of::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_H