backport the implementation of ranges::find{, _if, _if_not}

this will be required by future chromium releases

From ee0f8c4010309a25c95115a9f727a02741e2de48 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser@berlin.de>
Date: Sat, 12 Mar 2022 01:45:35 +0100
Subject: [PATCH] [libc++][ranges] Implement ranges::find{, _if, _if_not}

ok tb@

gnu/lib/libcxx/Makefile

@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.5 2021/12/17 14:55:43 patrick Exp $
+# $OpenBSD: Makefile,v 1.6 2023/07/05 15:34:52 robert Exp $
 
 .include <bsd.own.mk>
 
@@ -135,6 +135,9 @@ STD_HEADERS=	\
 	__algorithm/pop_heap.h \
 	__algorithm/prev_permutation.h \
 	__algorithm/push_heap.h \
+	__algorithm/ranges_find.h \
+	__algorithm/ranges_find_if.h \
+	__algorithm/ranges_find_if_not.h \
 	__algorithm/remove_copy_if.h \
 	__algorithm/remove_copy.h \
 	__algorithm/remove_if.h \

gnu/llvm/libcxx/include/__algorithm/ranges_find.h

@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_H
+
+#include <__algorithm/ranges_find_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.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 {
+struct __fn {
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Tp, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<_Ip, _Proj>, const _Tp*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, const _Tp& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return std::forward<decltype(__e)>(__e) == __value; };
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Rp, class _Tp, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Rp>, _Proj>, const _Tp*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, const _Tp& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return std::forward<decltype(__e)>(__e) == __value; };
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __find
+
+inline namespace __cpo {
+  inline constexpr auto find = __find::__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_H

gnu/llvm/libcxx/include/__algorithm/ranges_find_if.h

@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_IF_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.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 {
+
+template <class _Ip, class _Sp, class _Pred, class _Proj>
+_LIBCPP_HIDE_FROM_ABI static constexpr
+_Ip __find_if_impl(_Ip __first, _Sp __last, _Pred& __pred, _Proj& __proj) {
+  for (; __first != __last; ++__first) {
+    if (std::invoke(__pred, std::invoke(__proj, *__first)))
+      break;
+  }
+  return __first;
+}
+
+namespace __find_if {
+struct __fn {
+
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __find_if
+
+inline namespace __cpo {
+  inline constexpr auto find_if = __find_if::__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_IF_H

gnu/llvm/libcxx/include/__algorithm/ranges_find_if_not.h

@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_IF_NOT_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H
+
+#include <__algorithm/ranges_find_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.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_if_not {
+struct __fn {
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
+    auto __pred2 = [&](auto&& __e) { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred2, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
+    auto __pred2 = [&](auto&& __e) { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred2, __proj);
+  }
+};
+} // namespace __find_if_not
+
+inline namespace __cpo {
+  inline constexpr auto find_if_not = __find_if_not::__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_IF_NOT_H

gnu/llvm/libcxx/include/algorithm

@@ -18,6 +18,35 @@
 namespace std
 {
 
+namespace ranges {
+  template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
+    constexpr I find(I first, S last, const T& value, Proj proj = {});              // since C++20
+
+  template<input_range R, class T, class Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
+    constexpr borrowed_iterator_t<R>
+      find(R&& r, const T& value, Proj proj = {});                                  // since C++20
+
+  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
+           indirect_unary_predicate<projected<I, Proj>> Pred>
+    constexpr I find_if(I first, S last, Pred pred, Proj proj = {});                // since C++20
+
+  template<input_range R, class Proj = identity,
+           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
+    constexpr borrowed_iterator_t<R>
+      find_if(R&& r, Pred pred, Proj proj = {});                                    // since C++20
+
+  template<input_iterator I, sentinel_for<I> S, class Proj = identity,
+           indirect_unary_predicate<projected<I, Proj>> Pred>
+    constexpr I find_if_not(I first, S last, Pred pred, Proj proj = {});            // since C++20
+
+  template<input_range R, class Proj = identity,
+           indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
+    constexpr borrowed_iterator_t<R>
+      find_if_not(R&& r, Pred pred, Proj proj = {});                                // since C++20
+}
+
 template <class InputIterator, class Predicate>
     constexpr bool     // constexpr in C++20
     all_of(InputIterator first, InputIterator last, Predicate pred);
@@ -720,6 +749,9 @@ template <class BidirectionalIterator, class Compare>
 #include <__algorithm/pop_heap.h>
 #include <__algorithm/prev_permutation.h>
 #include <__algorithm/push_heap.h>
+#include <__algorithm/ranges_find.h>
+#include <__algorithm/ranges_find_if.h>
+#include <__algorithm/ranges_find_if_not.h>
 #include <__algorithm/remove.h>
 #include <__algorithm/remove_copy.h>
 #include <__algorithm/remove_copy_if.h>

gnu/llvm/libcxx/include/module.modulemap

@@ -279,6 +279,9 @@ module std [system] {
       module pop_heap                 { private header "__algorithm/pop_heap.h" }
       module prev_permutation         { private header "__algorithm/prev_permutation.h" }
       module push_heap                { private header "__algorithm/push_heap.h" }
+      module ranges_find              { private header "__algorithm/ranges_find.h" }
+      module ranges_find_if           { private header "__algorithm/ranges_find_if.h" }
+      module ranges_find_if_not       { private header "__algorithm/ranges_find_if_not.h" }
       module remove                   { private header "__algorithm/remove.h" }
       module remove_copy              { private header "__algorithm/remove_copy.h" }
       module remove_copy_if           { private header "__algorithm/remove_copy_if.h" }