[libc++] ranges::find_last #91086
[libc++] ranges::find_last #91086
Conversation
|
Thank you for submitting a Pull Request (PR) to the LLVM Project! This PR will be automatically labeled and the relevant teams will be If you wish to, you can add reviewers by using the "Reviewers" section on this page. If this is not working for you, it is probably because you do not have write If you have received no comments on your PR for a week, you can request a review If you have further questions, they may be answered by the LLVM GitHub User Guide. You can also ask questions in a comment on this PR, on the LLVM Discord or on the forums. |
llvmbot
added
the
libc++
|
@llvm/pr-subscribers-libcxx Author: Andrew Sukach (soukatch) ChangesImplemented ranges::find_last. First time contributing to libc++, so let me know if you have any suggestions. Thanks! Full diff: https://github.com/llvm/llvm-project/pull/91086.diff 5 Files Affected:
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index fd7eb125e007b6..56cce0a42ca771 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -113,6 +113,7 @@ set(files
__algorithm/ranges_find_first_of.h
__algorithm/ranges_find_if.h
__algorithm/ranges_find_if_not.h
+ __algorithm/ranges_find_last.h
__algorithm/ranges_for_each.h
__algorithm/ranges_for_each_n.h
__algorithm/ranges_generate.h
diff --git a/libcxx/include/__algorithm/ranges_find_last.h b/libcxx/include/__algorithm/ranges_find_last.h
new file mode 100644
index 00000000000000..b656d3b3e732ff
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_find_last.h
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_LAST_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_LAST_H
+
+#include <__algorithm/ranges_find.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 <__iterator/reverse_iterator.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__ranges/subrange.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+#if _LIBCPP_STD_VER >= 23
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+namespace __find_last {
+struct __fn {
+ template <forward_iterator _It, sentinel_for<_It> _Sent, typename _Tp, typename _Proj = identity>
+ requires indirect_binary_predicate<equal_to, projected<_It, _Proj>, const _Tp*>
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange<_It>
+ operator()(_It __first, _Sent __last, const _Tp& __value, _Proj __proj = {}) const {
+ if constexpr (same_as<_It, _Sent> && bidirectional_iterator<_It>) {
+ const auto __found{find(reverse_iterator{__last}, reverse_iterator{__first}, __value, std::move(__proj)).base()};
+ if (__found == __first)
+ return {__last, __last};
+ return {prev(__found), __last};
+ } else {
+ auto __found{find(__first, __last, __value, __proj)};
+ if (__found == __last)
+ return {__last, __last};
+
+ for (__first = __found;; __found = __first++)
+ if ((__first == find(__first, __last, __value, __proj)) == __last)
+ return {__found, __last};
+ }
+ }
+
+ template <forward_range _Range, typename _Tp, typename _Proj = identity>
+ requires indirect_binary_predicate<equal_to, projected<iterator_t<_Range>, _Proj>, const _Tp*>
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range>
+ operator()(_Range&& __r, const _Tp& __value, _Proj __proj = {}) const {
+ return this->operator()(begin(__r), end(__r), __value, std::move(__proj));
+ }
+};
+
+} // namespace __find_last
+
+inline namespace __cpo {
+inline constexpr __find_last::__fn find_last{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER >= 23
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_LAST_H
\ No newline at end of file
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 869fc19737b572..508579c75610a4 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -2004,6 +2004,7 @@ template <class BidirectionalIterator, class Compare>
# include <__algorithm/fold.h>
# include <__algorithm/ranges_contains_subrange.h>
# include <__algorithm/ranges_ends_with.h>
+# include <__algorithm/ranges_find_last.h>
# include <__algorithm/ranges_starts_with.h>
#endif // _LIBCPP_STD_VER >= 23
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
index 2974d12500c4cb..f354bca3ca45b3 100644
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -787,6 +787,7 @@ module std_private_algorithm_ranges_find_end [system
module std_private_algorithm_ranges_find_first_of [system] { header "__algorithm/ranges_find_first_of.h" }
module std_private_algorithm_ranges_find_if [system] { header "__algorithm/ranges_find_if.h" }
module std_private_algorithm_ranges_find_if_not [system] { header "__algorithm/ranges_find_if_not.h" }
+module std_private_algorithm_ranges_find_last [system] { header "__algorithm/ranges_find_last.h" }
module std_private_algorithm_ranges_for_each [system] {
header "__algorithm/ranges_for_each.h"
export std_private_algorithm_in_fun_result
diff --git a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
index 9645bff18ae72b..789d03e66d3c37 100644
--- a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
+++ b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
@@ -183,6 +183,7 @@ if (current_toolchain == default_toolchain) {
"__algorithm/ranges_find_first_of.h",
"__algorithm/ranges_find_if.h",
"__algorithm/ranges_find_if_not.h",
+ "__algorithm/ranges_find_last.h",
"__algorithm/ranges_for_each.h",
"__algorithm/ranges_for_each_n.h",
"__algorithm/ranges_generate.h",
|
|
I think there is an existing patch. #67270 |
Thanks for the heads up, my bad. I was just looking to use it and noticed it hadn't yet been implemented. Closing the pr now. |
If you want to contribute to ranges, you should look at the already merged PRs about what it takes to complete such a project and then ask on the libc++ Discord channel if it's free for the grabs (maybe somebody else is working on it). |
Will do. Thank's for the advice! |
Implemented ranges::find_last. First time contributing to libc++, so let me know if you have any suggestions. Thanks!