[libc++] Implement ranges::equal
Reviewed By: var-const, #libc
Spies: libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D123681
NOKEYCHECK=True
GitOrigin-RevId: 569d6630204d5146aee7c0f40872cf529181d9ef
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 68482bf..65261da 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -72,6 +72,7 @@
__algorithm/ranges_copy_n.h
__algorithm/ranges_count.h
__algorithm/ranges_count_if.h
+ __algorithm/ranges_equal.h
__algorithm/ranges_fill.h
__algorithm/ranges_fill_n.h
__algorithm/ranges_find.h
diff --git a/include/__algorithm/ranges_equal.h b/include/__algorithm/ranges_equal.h
new file mode 100644
index 0000000..c5f2d23
--- /dev/null
+++ b/include/__algorithm/ranges_equal.h
@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_EQUAL_H
+#define _LIBCPP___ALGORITHM_RANGES_EQUAL_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/distance.h>
+#include <__iterator/indirectly_comparable.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 __equal {
+struct __fn {
+private:
+ template <class _Iter1, class _Sent1,
+ class _Iter2, class _Sent2,
+ class _Pred,
+ class _Proj1,
+ class _Proj2>
+ _LIBCPP_HIDE_FROM_ABI constexpr static
+ bool __equal_impl(_Iter1 __first1, _Sent1 __last1,
+ _Iter2 __first2, _Sent2 __last2,
+ _Pred& __pred,
+ _Proj1& __proj1,
+ _Proj2& __proj2) {
+ while (__first1 != __last1 && __first2 != __last2) {
+ if (!std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
+ return false;
+ ++__first1;
+ ++__first2;
+ }
+ return __first1 == __last1 && __first2 == __last2;
+ }
+
+public:
+
+ template <input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+ input_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
+ bool operator()(_Iter1 __first1, _Sent1 __last1,
+ _Iter2 __first2, _Sent2 __last2,
+ _Pred __pred = {},
+ _Proj1 __proj1 = {},
+ _Proj2 __proj2 = {}) const {
+ if constexpr (sized_sentinel_for<_Sent1, _Iter1> && sized_sentinel_for<_Sent2, _Iter2>) {
+ if (__last1 - __first1 != __last2 - __first2)
+ return false;
+ }
+ return __equal_impl(std::move(__first1), std::move(__last1),
+ std::move(__first2), std::move(__last2),
+ __pred,
+ __proj1,
+ __proj2);
+ }
+
+ template <input_range _Range1,
+ input_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
+ bool operator()(_Range1&& __range1,
+ _Range2&& __range2,
+ _Pred __pred = {},
+ _Proj1 __proj1 = {},
+ _Proj2 __proj2 = {}) const {
+ if constexpr (sized_range<_Range1> && sized_range<_Range2>) {
+ if (ranges::distance(__range1) != ranges::distance(__range2))
+ return false;
+ }
+ return __equal_impl(ranges::begin(__range1), ranges::end(__range1),
+ ranges::begin(__range2), ranges::end(__range2),
+ __pred,
+ __proj1,
+ __proj2);
+ return false;
+ }
+};
+} // namespace __equal
+
+inline namespace __cpo {
+ inline constexpr auto equal = __equal::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_EQUAL_H
diff --git a/include/algorithm b/include/algorithm
index ba8ac23..aa21914 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -291,6 +291,20 @@
template<class T, output_iterator<const T&> O>
constexpr O ranges::fill_n(O first, iter_difference_t<O> n, const T& value); // since C++20
+
+ template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
+ class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+ requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
+ constexpr bool ranges::equal(I1 first1, S1 last1, I2 first2, S2 last2,
+ Pred pred = {},
+ Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+
+ template<input_range R1, input_range R2, class Pred = ranges::equal_to,
+ class Proj1 = identity, class Proj2 = identity>
+ requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
+ constexpr bool ranges::equal(R1&& r1, R2&& r2, Pred pred = {},
+ Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+
}
constexpr bool // constexpr in C++20
@@ -1013,6 +1027,7 @@
#include <__algorithm/ranges_copy_n.h>
#include <__algorithm/ranges_count.h>
#include <__algorithm/ranges_count_if.h>
+#include <__algorithm/ranges_equal.h>
#include <__algorithm/ranges_fill.h>
#include <__algorithm/ranges_fill_n.h>
#include <__algorithm/ranges_find.h>
diff --git a/include/module.modulemap b/include/module.modulemap
index d3a4b45..cf394de 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -304,6 +304,7 @@
module ranges_copy_n { private header "__algorithm/ranges_copy_n.h" }
module ranges_count { private header "__algorithm/ranges_count.h" }
module ranges_count_if { private header "__algorithm/ranges_count_if.h" }
+ module ranges_equal { private header "__algorithm/ranges_equal.h" }
module ranges_fill { private header "__algorithm/ranges_fill.h" }
module ranges_fill_n { private header "__algorithm/ranges_fill_n.h" }
module ranges_find { private header "__algorithm/ranges_find.h" }