[libc++] Implement ranges::is_partitioned
Reviewed By: var-const, #libc
Spies: libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D124440
NOKEYCHECK=True
GitOrigin-RevId: 37ba1b9d1ac729b1b05f11b684d352ec34646379
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 257e9d5..b79f286 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -77,6 +77,7 @@
__algorithm/ranges_find_if_not.h
__algorithm/ranges_for_each.h
__algorithm/ranges_for_each_n.h
+ __algorithm/ranges_is_partitioned.h
__algorithm/ranges_max.h
__algorithm/ranges_max_element.h
__algorithm/ranges_min.h
diff --git a/include/__algorithm/ranges_is_partitioned.h b/include/__algorithm/ranges_is_partitioned.h
new file mode 100644
index 0000000..3d57289
--- /dev/null
+++ b/include/__algorithm/ranges_is_partitioned.h
@@ -0,0 +1,81 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_IS_PARTITIONED_H
+#define _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.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 __is_partitioned {
+struct __fn {
+
+ template <class _Iter, class _Sent, class _Proj, class _Pred>
+ _LIBCPP_HIDE_FROM_ABI constexpr static
+ bool __is_parititioned_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+ for (; __first != __last; ++__first) {
+ if (!std::invoke(__pred, std::invoke(__proj, *__first)))
+ break;
+ }
+
+ if (__first == __last)
+ return true;
+ ++__first;
+
+ for (; __first != __last; ++__first) {
+ if (std::invoke(__pred, std::invoke(__proj, *__first)))
+ return false;
+ }
+
+ return true;
+ }
+
+ template <input_iterator _Iter, sentinel_for<_Iter> _Sent,
+ class _Proj = identity,
+ indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ bool operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
+ return __is_parititioned_impl(std::move(__first), std::move(__last), __pred, __proj);
+ }
+
+ template <input_range _Range,
+ class _Proj = identity,
+ indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
+ return __is_parititioned_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+ }
+};
+} // namespace __is_partitioned
+
+inline namespace __cpo {
+ inline constexpr auto is_partitioned = __is_partitioned::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
diff --git a/include/algorithm b/include/algorithm
index 13b3064..1a75dc0 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -256,6 +256,15 @@
indirectly_unary_invocable<projected<I, Proj>> Fun>
constexpr ranges::for_each_n_result<I, Fun>
ranges::for_each_n(I first, iter_difference_t<I> n, Fun f, Proj proj = {}); // since C++20
+
+ template<input_iterator I, sentinel_for<I> S, class Proj = identity,
+ indirect_unary_predicate<projected<I, Proj>> Pred>
+ constexpr bool ranges::is_partitioned(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 bool ranges::is_partitioned(R&& r, Pred pred, Proj proj = {}); // since C++20
+
}
constexpr bool // constexpr in C++20
@@ -983,6 +992,7 @@
#include <__algorithm/ranges_find_if_not.h>
#include <__algorithm/ranges_for_each.h>
#include <__algorithm/ranges_for_each_n.h>
+#include <__algorithm/ranges_is_partitioned.h>
#include <__algorithm/ranges_max.h>
#include <__algorithm/ranges_max_element.h>
#include <__algorithm/ranges_min.h>
diff --git a/include/module.modulemap b/include/module.modulemap
index c027bdc..c291901 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -305,6 +305,7 @@
module ranges_find_if_not { private header "__algorithm/ranges_find_if_not.h" }
module ranges_for_each { private header "__algorithm/ranges_for_each.h" }
module ranges_for_each_n { private header "__algorithm/ranges_for_each_n.h" }
+ module ranges_is_partitioned { private header "__algorithm/ranges_is_partitioned.h" }
module ranges_max { private header "__algorithm/ranges_max.h" }
module ranges_max_element { private header "__algorithm/ranges_max_element.h" }
module ranges_min { private header "__algorithm/ranges_min.h" }