[libcxx-commits] [libcxx] [libc++] P2502R2: `std::generator` (PR #201854)
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libcxx-commits at lists.llvm.org
Fri Jun 5 08:28:11 PDT 2026
https://github.com/c8ef updated https://github.com/llvm/llvm-project/pull/201854
>From 22f5fee287889d72cb171751fdc0993197c69b6b Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Fri, 5 Jun 2026 22:45:16 +0800
Subject: [PATCH 1/3] implement generator
---
libcxx/docs/FeatureTestMacroTable.rst | 2 +
libcxx/docs/Status/Cxx23Issues.csv | 2 +-
libcxx/docs/Status/Cxx23Papers.csv | 4 +-
libcxx/docs/Status/Cxx2cIssues.csv | 8 +-
libcxx/include/CMakeLists.txt | 1 +
libcxx/include/generator | 603 ++++++++++++++++++
libcxx/include/module.modulemap.in | 5 +
libcxx/include/version | 2 +
libcxx/modules/std.compat.cppm.in | 3 -
libcxx/modules/std.cppm.in | 4 +-
libcxx/modules/std/generator.inc | 7 +-
.../coro.generator/nodiscard.verify.cpp | 29 +
.../test/libcxx/transitive_includes/cxx03.csv | 21 +
.../test/libcxx/transitive_includes/cxx11.csv | 21 +
.../test/libcxx/transitive_includes/cxx14.csv | 21 +
.../test/libcxx/transitive_includes/cxx17.csv | 21 +
.../test/libcxx/transitive_includes/cxx20.csv | 16 +
.../test/libcxx/transitive_includes/cxx23.csv | 9 +
.../test/libcxx/transitive_includes/cxx26.csv | 9 +
.../generator.version.compile.pass.cpp | 65 ++
.../version.version.compile.pass.cpp | 30 +
.../ranges/coro.generator/allocator.pass.cpp | 123 ++++
.../coro.generator/generator.compile.pass.cpp | 48 ++
.../ranges/coro.generator/generator.pass.cpp | 56 ++
.../ranges/coro.generator/recursive.pass.cpp | 97 +++
.../generate_feature_test_macro_components.py | 5 +
libcxx/utils/libcxx/header_information.py | 1 -
27 files changed, 1198 insertions(+), 15 deletions(-)
create mode 100644 libcxx/include/generator
create mode 100644 libcxx/test/libcxx/ranges/coro.generator/nodiscard.verify.cpp
create mode 100644 libcxx/test/std/language.support/support.limits/support.limits.general/generator.version.compile.pass.cpp
create mode 100644 libcxx/test/std/ranges/coro.generator/allocator.pass.cpp
create mode 100644 libcxx/test/std/ranges/coro.generator/generator.compile.pass.cpp
create mode 100644 libcxx/test/std/ranges/coro.generator/generator.pass.cpp
create mode 100644 libcxx/test/std/ranges/coro.generator/recursive.pass.cpp
diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index 1b748e37293df..46d83644ff10f 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -344,6 +344,8 @@ Status
---------------------------------------------------------- -----------------
``__cpp_lib_forward_like`` ``202207L``
---------------------------------------------------------- -----------------
+ ``__cpp_lib_generator`` ``202207L``
+ ---------------------------------------------------------- -----------------
``__cpp_lib_invoke_r`` ``202106L``
---------------------------------------------------------- -----------------
``__cpp_lib_ios_noreplace`` ``202207L``
diff --git a/libcxx/docs/Status/Cxx23Issues.csv b/libcxx/docs/Status/Cxx23Issues.csv
index 0a2f0d59484de..b61edbd0a2975 100644
--- a/libcxx/docs/Status/Cxx23Issues.csv
+++ b/libcxx/docs/Status/Cxx23Issues.csv
@@ -217,7 +217,7 @@
"`LWG3759 <https://wg21.link/LWG3759>`__","``ranges::rotate_copy`` should use ``std::move``","2022-11 (Kona)","|Complete|","15","`#105027 <https://github.com/llvm/llvm-project/issues/105027>`__",""
"`LWG3760 <https://wg21.link/LWG3760>`__","``cartesian_product_view::iterator``'s ``parent_`` is never valid","2022-11 (Kona)","","","`#105028 <https://github.com/llvm/llvm-project/issues/105028>`__",""
"`LWG3761 <https://wg21.link/LWG3761>`__","``cartesian_product_view::iterator::operator-`` should pass by reference","2022-11 (Kona)","","","`#105029 <https://github.com/llvm/llvm-project/issues/105029>`__",""
-"`LWG3762 <https://wg21.link/LWG3762>`__","``generator::iterator::operator==`` should pass by reference","2022-11 (Kona)","","","`#105030 <https://github.com/llvm/llvm-project/issues/105030>`__",""
+"`LWG3762 <https://wg21.link/LWG3762>`__","``generator::iterator::operator==`` should pass by reference","2022-11 (Kona)","|Complete|","23","`#105030 <https://github.com/llvm/llvm-project/issues/105030>`__",""
"`LWG3764 <https://wg21.link/LWG3764>`__","``reference_wrapper::operator()`` should propagate noexcept","2022-11 (Kona)","|Complete|","17","`#105031 <https://github.com/llvm/llvm-project/issues/105031>`__",""
"`LWG3765 <https://wg21.link/LWG3765>`__","``const_sentinel`` should be constrained","2022-11 (Kona)","","","`#105032 <https://github.com/llvm/llvm-project/issues/105032>`__",""
"`LWG3766 <https://wg21.link/LWG3766>`__","``view_interface::cbegin`` is underconstrained","2022-11 (Kona)","","","`#105033 <https://github.com/llvm/llvm-project/issues/105033>`__",""
diff --git a/libcxx/docs/Status/Cxx23Papers.csv b/libcxx/docs/Status/Cxx23Papers.csv
index eb580ea891f5b..862461f900dbd 100644
--- a/libcxx/docs/Status/Cxx23Papers.csv
+++ b/libcxx/docs/Status/Cxx23Papers.csv
@@ -80,7 +80,7 @@
"`P2474R2 <https://wg21.link/P2474R2>`__","``views::repeat``","2022-07 (Virtual)","|Complete|","17","`#105222 <https://github.com/llvm/llvm-project/issues/105222>`__",""
"`P2494R2 <https://wg21.link/P2494R2>`__","Relaxing range adaptors to allow for move only types","2022-07 (Virtual)","|Complete|","17","`#105224 <https://github.com/llvm/llvm-project/issues/105224>`__",""
"`P2499R0 <https://wg21.link/P2499R0>`__","``string_view`` range constructor should be ``explicit``","2022-07 (Virtual)","|Complete|","16","`#105225 <https://github.com/llvm/llvm-project/issues/105225>`__",""
-"`P2502R2 <https://wg21.link/P2502R2>`__","``std::generator``: Synchronous Coroutine Generator for Ranges","2022-07 (Virtual)","","","`#105226 <https://github.com/llvm/llvm-project/issues/105226>`__",""
+"`P2502R2 <https://wg21.link/P2502R2>`__","``std::generator``: Synchronous Coroutine Generator for Ranges","2022-07 (Virtual)","|Complete|","23","`#105226 <https://github.com/llvm/llvm-project/issues/105226>`__",""
"`P2508R1 <https://wg21.link/P2508R1>`__","Exposing ``std::basic-format-string``","2022-07 (Virtual)","|Complete|","15","`#105227 <https://github.com/llvm/llvm-project/issues/105227>`__",""
"`P2517R1 <https://wg21.link/P2517R1>`__","Add a conditional ``noexcept`` specification to ``std::apply``","2022-07 (Virtual)","|Complete|","3.9","`#105229 <https://github.com/llvm/llvm-project/issues/105229>`__",""
"`P2520R0 <https://wg21.link/P2520R0>`__","``move_iterator`` should be a random access iterator","2022-07 (Virtual)","|Complete|","17","`#105230 <https://github.com/llvm/llvm-project/issues/105230>`__","Implemented as a DR in C++20"
@@ -115,7 +115,7 @@
"`P2674R1 <https://wg21.link/P2674R1>`__","A trait for implicit lifetime types","2023-02 (Issaquah)","|Complete|","20","`#105259 <https://github.com/llvm/llvm-project/issues/105259>`__",""
"`P2655R3 <https://wg21.link/P2655R3>`__","``common_reference_t`` of ``reference_wrapper`` Should Be a Reference Type","2023-02 (Issaquah)","|Complete|","21","`#105260 <https://github.com/llvm/llvm-project/issues/105260>`__","The paper is implemented as a DR to C++20"
"`P2652R2 <https://wg21.link/P2652R2>`__","Disallow User Specialization of ``allocator_traits``","2023-02 (Issaquah)","|Complete|","19","`#105262 <https://github.com/llvm/llvm-project/issues/105262>`__",""
-"`P2787R1 <https://wg21.link/P2787R1>`__","``pmr::generator`` - Promise Types are not Values","2023-02 (Issaquah)","","","`#105263 <https://github.com/llvm/llvm-project/issues/105263>`__",""
+"`P2787R1 <https://wg21.link/P2787R1>`__","``pmr::generator`` - Promise Types are not Values","2023-02 (Issaquah)","|Complete|","23","`#105263 <https://github.com/llvm/llvm-project/issues/105263>`__",""
"`P2614R2 <https://wg21.link/P2614R2>`__","Deprecate ``numeric_limits::has_denorm``","2023-02 (Issaquah)","|Complete|","18","`#105264 <https://github.com/llvm/llvm-project/issues/105264>`__",""
"`P2588R3 <https://wg21.link/P2588R3>`__","``barrier``’s phase completion guarantees","2023-02 (Issaquah)","","","`#105265 <https://github.com/llvm/llvm-project/issues/105265>`__",""
"`P2763R1 <https://wg21.link/P2763R1>`__","``layout_stride`` static extents default constructor fix","2023-02 (Issaquah)","","","`#105266 <https://github.com/llvm/llvm-project/issues/105266>`__",""
diff --git a/libcxx/docs/Status/Cxx2cIssues.csv b/libcxx/docs/Status/Cxx2cIssues.csv
index 6a836c0491bb6..3ec8ae821ed5d 100644
--- a/libcxx/docs/Status/Cxx2cIssues.csv
+++ b/libcxx/docs/Status/Cxx2cIssues.csv
@@ -4,7 +4,7 @@
"`LWG3885 <https://wg21.link/LWG3885>`__","``op`` should be in [zombie.names]","2023-06 (Varna)","|Nothing To Do|","","`#105270 <https://github.com/llvm/llvm-project/issues/105270>`__",""
"`LWG3887 <https://wg21.link/LWG3887>`__","Version macro for ``allocate_at_least``","2023-06 (Varna)","|Complete|","19","`#105271 <https://github.com/llvm/llvm-project/issues/105271>`__",""
"`LWG3893 <https://wg21.link/LWG3893>`__","LWG 3661 broke ``atomic<shared_ptr<T>> a; a = nullptr;``","2023-06 (Varna)","","","`#105273 <https://github.com/llvm/llvm-project/issues/105273>`__",""
-"`LWG3894 <https://wg21.link/LWG3894>`__","``generator::promise_type::yield_value(ranges::elements_of<Rng, Alloc>)`` should not be ``noexcept``","2023-06 (Varna)","","","`#105274 <https://github.com/llvm/llvm-project/issues/105274>`__",""
+"`LWG3894 <https://wg21.link/LWG3894>`__","``generator::promise_type::yield_value(ranges::elements_of<Rng, Alloc>)`` should not be ``noexcept``","2023-06 (Varna)","|Complete|","23","`#105274 <https://github.com/llvm/llvm-project/issues/105274>`__",""
"`LWG3903 <https://wg21.link/LWG3903>`__","span destructor is redundantly noexcept","2023-06 (Varna)","|Complete|","7","`#105275 <https://github.com/llvm/llvm-project/issues/105275>`__",""
"`LWG3904 <https://wg21.link/LWG3904>`__","``lazy_split_view::outer-iterator``'s const-converting constructor isn't setting ``trailing_empty_``","2023-06 (Varna)","","","`#105276 <https://github.com/llvm/llvm-project/issues/105276>`__",""
"`LWG3905 <https://wg21.link/LWG3905>`__","Type of ``std::fexcept_t``","2023-06 (Varna)","|Complete|","3.4","`#105277 <https://github.com/llvm/llvm-project/issues/105277>`__",""
@@ -79,8 +79,8 @@
"`LWG3216 <https://wg21.link/LWG3216>`__","Rebinding the allocator before calling ``construct``/``destroy`` in ``allocate_shared``","2024-11 (Wrocław)","","","`#118332 <https://github.com/llvm/llvm-project/issues/118332>`__",""
"`LWG3436 <https://wg21.link/LWG3436>`__","``std::construct_at`` should support arrays","2024-11 (Wrocław)","","","`#118335 <https://github.com/llvm/llvm-project/issues/118335>`__",""
"`LWG3886 <https://wg21.link/LWG3886>`__","Monad mo' problems","2024-11 (Wrocław)","|Complete|","22","`#118336 <https://github.com/llvm/llvm-project/issues/118336>`__",""
-"`LWG3899 <https://wg21.link/LWG3899>`__","``co_yield``\ing elements of an lvalue generator is unnecessarily inefficient","2024-11 (Wrocław)","","","`#118337 <https://github.com/llvm/llvm-project/issues/118337>`__",""
-"`LWG3900 <https://wg21.link/LWG3900>`__","The ``allocator_arg_t`` overloads of ``generator::promise_type::operator new`` should not be constrained","2024-11 (Wrocław)","","","`#118338 <https://github.com/llvm/llvm-project/issues/118338>`__",""
+"`LWG3899 <https://wg21.link/LWG3899>`__","``co_yield``\ing elements of an lvalue generator is unnecessarily inefficient","2024-11 (Wrocław)","|Complete|","23","`#118337 <https://github.com/llvm/llvm-project/issues/118337>`__",""
+"`LWG3900 <https://wg21.link/LWG3900>`__","The ``allocator_arg_t`` overloads of ``generator::promise_type::operator new`` should not be constrained","2024-11 (Wrocław)","|Complete|","23","`#118338 <https://github.com/llvm/llvm-project/issues/118338>`__",""
"`LWG3918 <https://wg21.link/LWG3918>`__","``std::uninitialized_move/_n`` and guaranteed copy elision","2024-11 (Wrocław)","","","`#118339 <https://github.com/llvm/llvm-project/issues/118339>`__",""
"`LWG4014 <https://wg21.link/LWG4014>`__","LWG 3809 changes behavior of some existing ``std::subtract_with_carry_engine code``","2024-11 (Wrocław)","","","`#118340 <https://github.com/llvm/llvm-project/issues/118340>`__",""
"`LWG4024 <https://wg21.link/LWG4024>`__","Underspecified destruction of objects created in ``std::make_shared_for_overwrite``/``std::allocate_shared_for_overwrite``","2024-11 (Wrocław)","|Complete|","16","`#118341 <https://github.com/llvm/llvm-project/issues/118341>`__",""
@@ -93,7 +93,7 @@
"`LWG4088 <https://wg21.link/LWG4088>`__","``println`` ignores the locale imbued in ``std::ostream``","2024-11 (Wrocław)","|Complete|","18","`#118348 <https://github.com/llvm/llvm-project/issues/118348>`__",""
"`LWG4112 <https://wg21.link/LWG4112>`__","``has-arrow`` should required ``operator->()`` to be ``const``-qualified","2024-11 (Wrocław)","","","`#118349 <https://github.com/llvm/llvm-project/issues/118349>`__",""
"`LWG4113 <https://wg21.link/LWG4113>`__","Disallow ``has_unique_object_representations<Incomplete[]>``","2024-11 (Wrocław)","|Complete|","","`#118350 <https://github.com/llvm/llvm-project/issues/118350>`__",""
-"`LWG4119 <https://wg21.link/LWG4119>`__","``generator::promise_type::yield_value(ranges::elements_of<R, Alloc>)``'s nested ``generator`` may be ill-formed","2024-11 (Wrocław)","","","`#118351 <https://github.com/llvm/llvm-project/issues/118351>`__",""
+"`LWG4119 <https://wg21.link/LWG4119>`__","``generator::promise_type::yield_value(ranges::elements_of<R, Alloc>)``'s nested ``generator`` may be ill-formed","2024-11 (Wrocław)","|Complete|","23","`#118351 <https://github.com/llvm/llvm-project/issues/118351>`__",""
"`LWG4124 <https://wg21.link/LWG4124>`__","Cannot format ``zoned_time`` with resolution coarser than ``seconds``","2024-11 (Wrocław)","","","`#118352 <https://github.com/llvm/llvm-project/issues/118352>`__",""
"`LWG4126 <https://wg21.link/LWG4126>`__","Some feature-test macros for fully freestanding features are not yet marked freestanding","2024-11 (Wrocław)","","","`#118353 <https://github.com/llvm/llvm-project/issues/118353>`__",""
"`LWG4134 <https://wg21.link/LWG4134>`__","Issue with Philox algorithm specification","2024-11 (Wrocław)","","","`#118354 <https://github.com/llvm/llvm-project/issues/118354>`__",""
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index 10dfb4b4d58cb..cd77d51924571 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -1043,6 +1043,7 @@ set(files
fstream
functional
future
+ generator
initializer_list
iomanip
ios
diff --git a/libcxx/include/generator b/libcxx/include/generator
new file mode 100644
index 0000000000000..d3f942b089002
--- /dev/null
+++ b/libcxx/include/generator
@@ -0,0 +1,603 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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_GENERATOR
+#define _LIBCPP_GENERATOR
+
+/*
+
+namespace std {
+ // [coro.generator.class], class template generator
+ template<class Ref, class Val = void, class Allocator = void>
+ class generator;
+
+ namespace pmr {
+ template<class Ref, class Val = void>
+ using generator = std::generator<Ref, Val, polymorphic_allocator<>>;
+ }
+}
+
+*/
+
+#include <__algorithm/max.h>
+#include <__assert>
+#include <__concepts/common_reference_with.h>
+#include <__concepts/constructible.h>
+#include <__concepts/convertible_to.h>
+#include <__concepts/same_as.h>
+#include <__config>
+#include <__coroutine/coroutine_handle.h>
+#include <__coroutine/coroutine_traits.h>
+#include <__coroutine/noop_coroutine_handle.h>
+#include <__coroutine/trivial_awaitables.h>
+#include <__exception/exception_ptr.h>
+#include <__iterator/default_sentinel.h>
+#include <__memory/addressof.h>
+#include <__memory/allocator_arg_t.h>
+#include <__memory/allocator_traits.h>
+#include <__memory/construct_at.h>
+#include <__memory_resource/polymorphic_allocator.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/elements_of.h>
+#include <__ranges/view_interface.h>
+#include <__type_traits/add_pointer.h>
+#include <__type_traits/common_reference.h>
+#include <__type_traits/conditional.h>
+#include <__type_traits/is_nothrow_constructible.h>
+#include <__type_traits/is_object.h>
+#include <__type_traits/is_pointer.h>
+#include <__type_traits/is_reference.h>
+#include <__type_traits/is_void.h>
+#include <__type_traits/remove_cvref.h>
+#include <__type_traits/remove_reference.h>
+#include <__utility/exchange.h>
+#include <__utility/move.h>
+#include <__utility/swap.h>
+#include <cstdint>
+#include <new>
+
+#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
+
+template <class _Ref, class _Val>
+using __gen_val = conditional_t<is_void_v<_Val>, remove_cvref_t<_Ref>, _Val>;
+
+template <class _Ref, class _Val>
+using __gen_ref = conditional_t<is_void_v<_Val>, _Ref&&, _Ref>;
+
+template <class _Ref, class _Val>
+using __gen_yielded =
+ conditional_t<is_reference_v<__gen_ref<_Ref, _Val>>, __gen_ref<_Ref, _Val>, const __gen_ref<_Ref, _Val>&>;
+
+template <class, class>
+struct __gen_iter_provider {
+ class __iterator;
+};
+
+template <class, class, class>
+class generator;
+
+template <class _Yielded>
+class __gen_promise_base {
+private:
+ template <class, class, class>
+ friend class generator;
+
+ template <class, class>
+ friend struct __gen_iter_provider;
+
+ // Each promise object stores either a `__root_data` when associated with a root generator, or a `__recursive_data`
+ // when associated with a generator that is yielded recursively.
+ struct __root_data {
+ // The client code has access only to the iterator of the root generator. Thus, the root generator must store the
+ // yielded values of recursively-yielded generators, which will then be returned when the client code dereferences
+ // the iterator.
+ add_pointer_t<_Yielded> __value_ptr;
+ // The client code has access only to the iterator of the root generator. Thus, the root generator needs to identify
+ // which generator is currently active. This active generator will then be resumed when the client code increments
+ // the iterator.
+ coroutine_handle<__gen_promise_base> __active;
+ };
+
+ struct __recursive_data {
+ exception_ptr __exception;
+ coroutine_handle<__gen_promise_base> __parent;
+ coroutine_handle<__gen_promise_base> __root;
+ };
+
+ union __union {
+ __root_data __root;
+ __recursive_data __recursive;
+
+ _LIBCPP_HIDE_FROM_ABI ~__union() noexcept {}
+ } __data_;
+
+ // The `__tag_` stores the active member of the `__data_` union:
+ // - `false` indicates that the active member is `__root`.
+ // - `true` indicates that the active member is `__recursive`.
+ // This field can be omitted because `__recursive_data.__root` can store the active member.
+ bool __tag_;
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool __is_root() noexcept { return !__tag_; }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __root_data& __get_root_data() noexcept {
+ _LIBCPP_ASSERT_INTERNAL(__is_root(), "the active member of `__data_` is not `__root`");
+ return __data_.__root;
+ }
+ _LIBCPP_HIDE_FROM_ABI void __set_root_tag() noexcept { __tag_ = false; }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool __is_recursive() noexcept { return __tag_; }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __recursive_data& __get_recursive_data() noexcept {
+ _LIBCPP_ASSERT_INTERNAL(__is_recursive(), "the active member of `__data_` is not `__recursive`");
+ return __data_.__recursive;
+ }
+ _LIBCPP_HIDE_FROM_ABI void __set_recursive_tag() noexcept { __tag_ = true; }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI coroutine_handle<__gen_promise_base>& __active() noexcept {
+ _LIBCPP_ASSERT_INTERNAL(__is_root(), "the active member of `__data_` is not `__root`");
+ return __get_root_data().__active;
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI add_pointer_t<_Yielded>& __value_ptr() noexcept {
+ _LIBCPP_ASSERT_INTERNAL(__is_root(), "the active member of `__data_` is not `__root`");
+ return __get_root_data().__value_ptr;
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI add_pointer_t<_Yielded>& __root_value_ptr() noexcept {
+ if (__is_root()) {
+ return __value_ptr();
+ }
+ return __get_recursive_data().__root.promise().__value_ptr();
+ }
+
+ struct __element_awaiter {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool await_ready() noexcept { return false; }
+
+ template <class _Promise>
+ _LIBCPP_HIDE_FROM_ABI void await_suspend(coroutine_handle<_Promise> __current) noexcept {
+ __current.promise().__root_value_ptr() = std::addressof(__value);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void await_resume() noexcept {}
+
+ remove_cvref_t<_Yielded> __value;
+ };
+
+ struct __final_awaiter {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool await_ready() noexcept { return false; }
+
+ template <class _Promise>
+ _LIBCPP_HIDE_FROM_ABI coroutine_handle<> await_suspend(coroutine_handle<_Promise> __current) noexcept {
+ // Checks if the current generator is recursively-yielded
+ if (__current.promise().__is_recursive()) {
+ auto&& __recursive_data = __current.promise().__get_recursive_data();
+ auto __parent = __recursive_data.__parent;
+ // Updates the active generator to its parent, allowing the client code to resume it later
+ __recursive_data.__root.promise().__active() = __parent;
+ // Transfers execution to its parent, which is the generator that yields it
+ return __parent;
+ }
+ return std::noop_coroutine();
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void await_resume() noexcept {}
+ };
+
+ template <class _Ref, class _Val, class _Allocator>
+ struct __recursive_awaiter {
+ _LIBCPP_HIDE_FROM_ABI explicit __recursive_awaiter(generator<_Ref, _Val, _Allocator>&& __gen) noexcept
+ : __gen_{std::move(__gen)} {}
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI bool await_ready() noexcept { return !__gen_.__coroutine_; }
+
+ template <class _Promise>
+ _LIBCPP_HIDE_FROM_ABI coroutine_handle<__gen_promise_base>
+ await_suspend(coroutine_handle<_Promise> __current) noexcept {
+ // Stores a `__recursive_data` in the promise object associated with `__gen`
+ auto __recursive = coroutine_handle<__gen_promise_base>::from_address(__gen_.__coroutine_.address());
+ __recursive.promise().__set_recursive_tag();
+ auto&& __recursive_data = __recursive.promise().__get_recursive_data();
+
+ // Sets `__recursive_data.__parent` to the current generator
+ auto __parent = coroutine_handle<__gen_promise_base>::from_address(__current.address());
+ __recursive_data.__parent = __parent;
+
+ // Sets `__recursive_data.__root` to the current generator if it's a root generator, or to the root generator of
+ // the current generator otherwise
+ if (__parent.promise().__is_recursive()) {
+ __recursive_data.__root = __parent.promise().__get_recursive_data().__root;
+ } else {
+ __recursive_data.__root = __parent;
+ }
+
+ // Updates the active generator to `__gen`, allowing the client code to resume it later
+ __recursive_data.__root.promise().__active() = __recursive;
+
+ // Transfers execution to `__gen`
+ return __recursive;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void await_resume() {
+ auto __recursive = coroutine_handle<__gen_promise_base>::from_address(__gen_.__coroutine_.address());
+ auto&& __recursive_data = __recursive.promise().__get_recursive_data();
+ if (__recursive_data.__exception) {
+ std::rethrow_exception(std::move(__recursive_data.__exception));
+ }
+ }
+
+ private:
+ generator<_Ref, _Val, _Allocator> __gen_;
+ };
+
+public:
+ _LIBCPP_HIDE_FROM_ABI __gen_promise_base() noexcept
+ : __data_{.__root{
+ .__value_ptr{nullptr},
+ .__active{coroutine_handle<__gen_promise_base>::from_promise(*this)},
+ }},
+ __tag_{false} {}
+
+ _LIBCPP_HIDE_FROM_ABI ~__gen_promise_base() noexcept {
+ if (__is_root()) {
+ __data_.__root.~__root_data();
+ } else {
+ __data_.__recursive.~__recursive_data();
+ }
+ }
+
+ _LIBCPP_HIDE_FROM_ABI suspend_always initial_suspend() const noexcept { return {}; }
+
+ _LIBCPP_HIDE_FROM_ABI __final_awaiter final_suspend() noexcept { return {}; }
+
+ _LIBCPP_HIDE_FROM_ABI suspend_always yield_value(_Yielded __value) noexcept {
+ __root_value_ptr() = std::addressof(__value);
+ return {};
+ }
+
+ _LIBCPP_HIDE_FROM_ABI auto yield_value(const remove_reference_t<_Yielded>& __value) noexcept(
+ is_nothrow_constructible_v<remove_cvref_t<_Yielded>, const remove_reference_t<_Yielded>&>)
+ requires is_rvalue_reference_v<_Yielded> &&
+ constructible_from<remove_cvref_t<_Yielded>, const remove_reference_t<_Yielded>&>
+ {
+ return __element_awaiter{.__value{__value}};
+ }
+
+ template <class _Ref2, class _Val2, class _Allocator2, class _Unused>
+ requires same_as<__gen_yielded<_Ref2, _Val2>, _Yielded>
+ _LIBCPP_HIDE_FROM_ABI auto
+ yield_value(ranges::elements_of<generator<_Ref2, _Val2, _Allocator2>&&, _Unused> __elements) noexcept {
+ return __recursive_awaiter<_Ref2, _Val2, _Allocator2>{std::move(__elements.range)};
+ }
+
+ template <class _Ref2, class _Val2, class _Allocator2, class _Unused>
+ requires same_as<__gen_yielded<_Ref2, _Val2>, _Yielded>
+ _LIBCPP_HIDE_FROM_ABI auto
+ yield_value(ranges::elements_of<generator<_Ref2, _Val2, _Allocator2>&, _Unused> __elements) noexcept {
+ return __recursive_awaiter<_Ref2, _Val2, _Allocator2>{std::move(__elements.range)};
+ }
+
+ template <ranges::input_range _Range, class _Allocator>
+ requires convertible_to<ranges::range_reference_t<_Range>, _Yielded>
+ _LIBCPP_HIDE_FROM_ABI auto yield_value(ranges::elements_of<_Range, _Allocator> __range) {
+ auto __lambda =
+ [](allocator_arg_t, _Allocator, ranges::iterator_t<_Range> __i, ranges::sentinel_t<_Range> __s) static
+ -> generator<_Yielded, void, _Allocator> {
+ for (; __i != __s; ++__i) {
+ co_yield static_cast<_Yielded>(*__i);
+ }
+ };
+ return yield_value(ranges::elements_of(
+ __lambda(allocator_arg, __range.allocator, ranges::begin(__range.range), ranges::end(__range.range))));
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void await_transform() = delete;
+
+ _LIBCPP_HIDE_FROM_ABI void return_void() const noexcept {}
+
+ _LIBCPP_HIDE_FROM_ABI void unhandled_exception() {
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ if (__is_root()) {
+ throw;
+ } else {
+ __get_recursive_data().__exception = std::current_exception();
+ }
+# endif
+ }
+};
+
+struct alignas(__STDCPP_DEFAULT_NEW_ALIGNMENT__) __gen_aligned_block {
+ char __data[__STDCPP_DEFAULT_NEW_ALIGNMENT__];
+
+ _LIBCPP_HIDE_FROM_ABI static size_t __count(const size_t __size) noexcept {
+ return (__size + sizeof(__gen_aligned_block) - 1) / sizeof(__gen_aligned_block);
+ }
+};
+
+template <class _Allocator>
+concept __gen_stateless_allocator =
+ default_initializable<_Allocator> && allocator_traits<_Allocator>::is_always_equal::value;
+
+template <class _Allocator>
+class __gen_promise_allocator {
+private:
+ using __rebind = allocator_traits<_Allocator>::template rebind_alloc<__gen_aligned_block>;
+ using __rebind_size_type = allocator_traits<__rebind>::size_type;
+
+ using __rebind_pointer = allocator_traits<__rebind>::pointer;
+ static_assert(is_pointer_v<__rebind_pointer>);
+
+ _LIBCPP_HIDE_FROM_ABI static void* __alloc(const _Allocator& __al, size_t __size) {
+ __rebind __rebind_al = static_cast<__rebind>(__al);
+
+ if constexpr (__gen_stateless_allocator<__rebind>) {
+ const size_t __block_count = __gen_aligned_block::__count(__size);
+ return __rebind_al.allocate(static_cast<__rebind_size_type>(__block_count));
+ } else {
+ // Allocates enough blocks for the coroutine frame, the size of the stateful allocator, and the alignment of the
+ // stateful allocator
+ const size_t __block_count = __gen_aligned_block::__count(__size + sizeof(__rebind) + alignof(__rebind));
+ void* const __ptr = __rebind_al.allocate(static_cast<__rebind_size_type>(__block_count));
+
+ // Stores the stateful allocator in the allocated block
+ __rebind* const __rebind_al_ptr = reinterpret_cast<__rebind*>(
+ (reinterpret_cast<uintptr_t>(__ptr) + __size + alignof(__rebind) - 1) & ~(alignof(__rebind) - 1));
+ std::construct_at(__rebind_al_ptr, std::move(__rebind_al));
+ return __ptr;
+ }
+ }
+
+public:
+ _LIBCPP_HIDE_FROM_ABI void* operator new(size_t __size)
+ requires default_initializable<_Allocator>
+ {
+ return __alloc({}, __size);
+ }
+
+ template <class _Allocator2, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI void* operator new(size_t __size, allocator_arg_t, const _Allocator2& __al, const _Args&...) {
+ return __alloc(static_cast<_Allocator>(__al), __size);
+ }
+
+ template <class _This, class _Allocator2, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI void*
+ operator new(size_t __size, const _This&, allocator_arg_t, const _Allocator2& __al, const _Args&...) {
+ return __alloc(static_cast<_Allocator>(__al), __size);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI static void operator delete(void* const __ptr, size_t __size) noexcept {
+ if constexpr (__gen_stateless_allocator<__rebind>) {
+ __rebind __rebind_al;
+ const size_t __block_count = __gen_aligned_block::__count(__size);
+ __rebind_al.deallocate(static_cast<__gen_aligned_block*>(__ptr), static_cast<__rebind_size_type>(__block_count));
+ } else {
+ // Retrieves the stateful allocator stored in the allocated block
+ __rebind* const __rebind_al_ptr = reinterpret_cast<__rebind*>(
+ (reinterpret_cast<uintptr_t>(__ptr) + __size + alignof(__rebind) - 1) & ~(alignof(__rebind) - 1));
+ __rebind __rebind_al = std::move(*__rebind_al_ptr);
+ std::destroy_at(__rebind_al_ptr);
+
+ const size_t __block_count = __gen_aligned_block::__count(__size + sizeof(__rebind) + alignof(__rebind));
+ __rebind_al.deallocate(static_cast<__gen_aligned_block*>(__ptr), static_cast<__rebind_size_type>(__block_count));
+ }
+ }
+};
+
+template <>
+class __gen_promise_allocator<void> {
+private:
+ using __dealloc_fn = void (*)(void*, size_t) noexcept;
+
+ template <class _Allocator>
+ _LIBCPP_HIDE_FROM_ABI static void* __alloc(const _Allocator& __al, size_t __size) {
+ using __rebind = allocator_traits<_Allocator>::template rebind_alloc<__gen_aligned_block>;
+ using __rebind_size_type = allocator_traits<__rebind>::size_type;
+
+ using __rebind_pointer = allocator_traits<__rebind>::pointer;
+ static_assert(is_pointer_v<__rebind_pointer>);
+
+ __rebind __rebind_al = static_cast<__rebind>(__al);
+ if constexpr (__gen_stateless_allocator<__rebind>) {
+ const size_t __block_count = __gen_aligned_block::__count(__size + sizeof(__dealloc_fn));
+ void* const __ptr = __rebind_al.allocate(static_cast<__rebind_size_type>(__block_count));
+
+ // Stores the deallocation function in the allocated block
+ __dealloc_fn* const __dealloc_ptr = reinterpret_cast<__dealloc_fn*>(reinterpret_cast<uintptr_t>(__ptr) + __size);
+ *__dealloc_ptr = __dealloc<__rebind>;
+ return __ptr;
+ } else {
+ // Allocates enough blocks for the coroutine frame, the size of the stateful allocator, the alignment of the
+ // stateful allocator, and the deallocation function
+ const size_t __block_count =
+ __gen_aligned_block::__count(__size + sizeof(__dealloc_fn) + sizeof(__rebind) + alignof(__rebind));
+ void* const __ptr = __rebind_al.allocate(static_cast<__rebind_size_type>(__block_count));
+
+ // Stores the deallocation function in the allocated block
+ __dealloc_fn* const __dealloc_ptr = reinterpret_cast<__dealloc_fn*>(reinterpret_cast<uintptr_t>(__ptr) + __size);
+ *__dealloc_ptr = __dealloc<__rebind>;
+
+ // Stores the stateful allocator in the allocated block
+ __rebind* const __rebind_al_ptr = reinterpret_cast<__rebind*>(
+ (reinterpret_cast<uintptr_t>(__ptr) + sizeof(__dealloc_fn) + __size + alignof(__rebind) - 1) &
+ ~(alignof(__rebind) - 1));
+ std::construct_at(__rebind_al_ptr, std::move(__rebind_al));
+ return __ptr;
+ }
+ }
+
+ template <class _Rebind>
+ _LIBCPP_HIDE_FROM_ABI static void __dealloc(void* const __ptr, size_t __size) noexcept {
+ using __rebind_size_type = allocator_traits<_Rebind>::size_type;
+
+ if constexpr (__gen_stateless_allocator<_Rebind>) {
+ _Rebind __rebind_al;
+ const size_t __block_count = __gen_aligned_block::__count(__size + sizeof(__dealloc_fn));
+ __rebind_al.deallocate(static_cast<__gen_aligned_block*>(__ptr), static_cast<__rebind_size_type>(__block_count));
+ } else {
+ // Retrieves the stateful allocator stored in the allocated block
+ _Rebind* const __rebind_al_ptr = reinterpret_cast<_Rebind*>(
+ (reinterpret_cast<uintptr_t>(__ptr) + __size + sizeof(__dealloc_fn) + alignof(_Rebind) - 1) &
+ ~(alignof(_Rebind) - 1));
+ _Rebind __rebind_al = std::move(*__rebind_al_ptr);
+ std::destroy_at(__rebind_al_ptr);
+
+ const size_t __block_count =
+ __gen_aligned_block::__count(__size + sizeof(__dealloc_fn) + sizeof(_Rebind) + alignof(_Rebind));
+ __rebind_al.deallocate(static_cast<__gen_aligned_block*>(__ptr), static_cast<__rebind_size_type>(__block_count));
+ }
+ }
+
+public:
+ _LIBCPP_HIDE_FROM_ABI void* operator new(size_t __size) {
+ void* const __ptr = ::operator new(__size + sizeof(__dealloc_fn));
+ __dealloc_fn __dealloc = [](void* const __dealloc_ptr, const size_t __dealloc_size) static noexcept -> void {
+ ::operator delete(__dealloc_ptr, __dealloc_size + sizeof(__dealloc_fn));
+ };
+
+ __dealloc_fn* const __dealloc_ptr = reinterpret_cast<__dealloc_fn*>(reinterpret_cast<uintptr_t>(__ptr) + __size);
+ *__dealloc_ptr = __dealloc;
+ return __ptr;
+ }
+
+ template <class _Allocator, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI void* operator new(size_t __size, allocator_arg_t, const _Allocator& __al, const _Args&...) {
+ return __alloc(__al, __size);
+ }
+
+ template <class _This, class _Allocator, class... _Args>
+ _LIBCPP_HIDE_FROM_ABI void*
+ operator new(size_t __size, const _This&, allocator_arg_t, const _Allocator& __al, const _Args&...) {
+ return __alloc(__al, __size);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI static void operator delete(void* const __ptr, size_t __size) noexcept {
+ __dealloc_fn* const __dealloc_ptr = reinterpret_cast<__dealloc_fn*>(reinterpret_cast<uintptr_t>(__ptr) + __size);
+ const __dealloc_fn __dealloc = *__dealloc_ptr;
+ __dealloc(__ptr, __size);
+ }
+};
+
+template <class _Ref, class _Val>
+class __gen_iter_provider<_Ref, _Val>::__iterator {
+private:
+ using __val = __gen_val<_Ref, _Val>;
+ using __ref = __gen_ref<_Ref, _Val>;
+
+public:
+ using value_type = __val;
+ using difference_type = ptrdiff_t;
+
+ _LIBCPP_HIDE_FROM_ABI explicit __iterator(
+ coroutine_handle<__gen_promise_base<__gen_yielded<_Ref, _Val>>> __coroutine) noexcept
+ : __coroutine_{__coroutine} {}
+
+ _LIBCPP_HIDE_FROM_ABI __iterator(__iterator&& __other) noexcept
+ : __coroutine_{std::exchange(__other.__coroutine_, {})} {}
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator=(__iterator&& __other) noexcept {
+ __coroutine_ = std::exchange(__other.__coroutine_, {});
+ return *this;
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __ref operator*() const noexcept(is_nothrow_copy_constructible_v<__ref>) {
+ return static_cast<__ref>(*__coroutine_.promise().__value_ptr());
+ }
+
+ _LIBCPP_HIDE_FROM_ABI __iterator& operator++() {
+ __coroutine_.promise().__active().resume();
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void operator++(int) { ++*this; }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI friend bool operator==(const __iterator& __iter, default_sentinel_t) noexcept {
+ return __iter.__coroutine_.done();
+ }
+
+private:
+ coroutine_handle<__gen_promise_base<__gen_yielded<_Ref, _Val>>> __coroutine_;
+};
+
+template <class _Ref, class _Val = void, class _Allocator = void>
+class generator : public ranges::view_interface<generator<_Ref, _Val, _Allocator>> {
+private:
+ using __val = __gen_val<_Ref, _Val>;
+ static_assert(same_as<remove_cvref_t<__val>, __val> && is_object_v<__val>);
+
+ using __ref = __gen_ref<_Ref, _Val>;
+ static_assert(is_reference_v<__ref> ||
+ (same_as<remove_cvref_t<__ref>, __ref> && is_object_v<__ref> && copy_constructible<__ref>));
+
+ using __rref = conditional_t<is_lvalue_reference_v<_Ref>, remove_reference_t<_Ref>&&, _Ref>;
+ static_assert(common_reference_with<__ref&&, __val&> && common_reference_with<__ref&&, __rref&&> &&
+ common_reference_with<__rref&&, const __val&>);
+
+ template <class>
+ friend class __gen_promise_base;
+
+public:
+ using yielded = __gen_yielded<_Ref, _Val>;
+
+ struct promise_type : __gen_promise_base<yielded>, __gen_promise_allocator<_Allocator> {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI generator get_return_object() noexcept {
+ return generator{coroutine_handle<promise_type>::from_promise(*this)};
+ }
+ };
+
+ _LIBCPP_HIDE_FROM_ABI generator(const generator&) = delete;
+ _LIBCPP_HIDE_FROM_ABI generator(generator&& __other) noexcept
+ : __coroutine_{std::exchange(__other.__coroutine_, {})} {}
+
+ _LIBCPP_HIDE_FROM_ABI ~generator() {
+ if (__coroutine_) {
+ __coroutine_.destroy();
+ }
+ }
+
+ _LIBCPP_HIDE_FROM_ABI generator& operator=(generator __other) noexcept {
+ std::swap(__coroutine_, __other.__coroutine_);
+ return *this;
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __gen_iter_provider<_Ref, _Val>::__iterator begin() {
+ auto __coroutine = coroutine_handle<__gen_promise_base<yielded>>::from_promise(__coroutine_.promise());
+ __coroutine.resume();
+ return typename __gen_iter_provider<_Ref, _Val>::__iterator{__coroutine};
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI default_sentinel_t end() const noexcept { return {}; }
+
+private:
+ _LIBCPP_HIDE_FROM_ABI explicit generator(coroutine_handle<promise_type> __coroutine) noexcept
+ : __coroutine_{__coroutine} {}
+
+ coroutine_handle<promise_type> __coroutine_;
+};
+
+namespace pmr {
+
+template <class _Ref, class _Val = void>
+using generator = std::generator<_Ref, _Val, polymorphic_allocator<>>;
+
+} // namespace pmr
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER >= 23
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_GENERATOR
diff --git a/libcxx/include/module.modulemap.in b/libcxx/include/module.modulemap.in
index 29f3818c39671..efb97a047c6e6 100644
--- a/libcxx/include/module.modulemap.in
+++ b/libcxx/include/module.modulemap.in
@@ -1476,6 +1476,11 @@ module std [system] {
export *
}
+ module generator {
+ header "generator"
+ export *
+ }
+
module iomanip {
header "iomanip"
export *
diff --git a/libcxx/include/version b/libcxx/include/version
index d4d29b4d31a72..8a73c95551793 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -133,6 +133,7 @@ __cpp_lib_fstream_native_handle 202306L <fstream>
__cpp_lib_function_ref 202306L <functional>
__cpp_lib_gcd_lcm 201606L <numeric>
__cpp_lib_generate_random 202403L <random>
+__cpp_lib_generator 202207L <generator>
__cpp_lib_generic_associative_lookup 201304L <map> <set>
__cpp_lib_generic_unordered_lookup 201811L <unordered_map> <unordered_set>
__cpp_lib_hardware_interference_size 201703L <new>
@@ -507,6 +508,7 @@ __cpp_lib_void_t 201411L <type_traits>
# define __cpp_lib_format_ranges 202207L
// # define __cpp_lib_formatters 202302L
# define __cpp_lib_forward_like 202207L
+# define __cpp_lib_generator 202207L
# define __cpp_lib_invoke_r 202106L
# define __cpp_lib_ios_noreplace 202207L
# if __has_builtin(__builtin_is_implicit_lifetime)
diff --git a/libcxx/modules/std.compat.cppm.in b/libcxx/modules/std.compat.cppm.in
index dd7385bf33a42..dada8f56f0224 100644
--- a/libcxx/modules/std.compat.cppm.in
+++ b/libcxx/modules/std.compat.cppm.in
@@ -51,9 +51,6 @@ module;
# if __has_include(<debugging>)
# error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
# endif // __has_include(<debugging>)
-# if __has_include(<generator>)
-# error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
-# endif // __has_include(<generator>)
# if __has_include(<hazard_pointer>)
# error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
# endif // __has_include(<hazard_pointer>)
diff --git a/libcxx/modules/std.cppm.in b/libcxx/modules/std.cppm.in
index 984b18321923c..0c484219c31ce 100644
--- a/libcxx/modules/std.cppm.in
+++ b/libcxx/modules/std.cppm.in
@@ -67,6 +67,7 @@ module;
#include <fstream>
#include <functional>
#include <future>
+#include <generator>
#include <initializer_list>
#include <iomanip>
#include <ios>
@@ -135,9 +136,6 @@ module;
# if __has_include(<debugging>)
# error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
# endif // __has_include(<debugging>)
-# if __has_include(<generator>)
-# error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
-# endif // __has_include(<generator>)
# if __has_include(<hazard_pointer>)
# error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
# endif // __has_include(<hazard_pointer>)
diff --git a/libcxx/modules/std/generator.inc b/libcxx/modules/std/generator.inc
index 43fb0daf5c659..8681f4b26dc46 100644
--- a/libcxx/modules/std/generator.inc
+++ b/libcxx/modules/std/generator.inc
@@ -8,7 +8,12 @@
//===----------------------------------------------------------------------===//
export namespace std {
-#if 0
+#if _LIBCPP_STD_VER >= 23
+ // [coro.generator], class template generator
using std::generator;
+
+ namespace pmr {
+ using std::pmr::generator;
+ }
#endif
} // namespace std
diff --git a/libcxx/test/libcxx/ranges/coro.generator/nodiscard.verify.cpp b/libcxx/test/libcxx/ranges/coro.generator/nodiscard.verify.cpp
new file mode 100644
index 0000000000000..9fb717bf9c148
--- /dev/null
+++ b/libcxx/test/libcxx/ranges/coro.generator/nodiscard.verify.cpp
@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++23
+
+// Check that functions are marked [[nodiscard]]
+
+#include <generator>
+
+std::generator<int> generate_ints() {
+ co_yield 1;
+ co_yield 2;
+ co_yield 3;
+}
+
+void test() {
+ auto gen = generate_ints();
+
+ // expected-warning at +1 {{ignoring return value of function declared with 'nodiscard' attribute}}
+ gen.begin();
+
+ // expected-warning at +1 {{ignoring return value of function declared with 'nodiscard' attribute}}
+ gen.end();
+}
diff --git a/libcxx/test/libcxx/transitive_includes/cxx03.csv b/libcxx/test/libcxx/transitive_includes/cxx03.csv
index c0031543e47bc..5754f5961dd09 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx03.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx03.csv
@@ -122,15 +122,19 @@ atomic ratio
atomic type_traits
atomic version
barrier atomic
+barrier cctype
barrier climits
barrier cmath
barrier compare
barrier concepts
barrier cstddef
barrier cstdint
+barrier cstdio
barrier cstdlib
barrier cstring
barrier ctime
+barrier cwchar
+barrier cwctype
barrier exception
barrier initializer_list
barrier iosfwd
@@ -945,6 +949,22 @@ future utility
future variant
future vector
future version
+generator cmath
+generator compare
+generator cstddef
+generator cstdint
+generator cstdlib
+generator cstring
+generator exception
+generator initializer_list
+generator iosfwd
+generator limits
+generator new
+generator tuple
+generator type_traits
+generator typeinfo
+generator utility
+generator version
initializer_list cstddef
initializer_list version
iomanip algorithm
@@ -2032,6 +2052,7 @@ stdexcept new
stdexcept type_traits
stdexcept typeinfo
stdexcept version
+stop_token cstddef
stop_token iosfwd
stop_token version
streambuf algorithm
diff --git a/libcxx/test/libcxx/transitive_includes/cxx11.csv b/libcxx/test/libcxx/transitive_includes/cxx11.csv
index c0031543e47bc..5754f5961dd09 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx11.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx11.csv
@@ -122,15 +122,19 @@ atomic ratio
atomic type_traits
atomic version
barrier atomic
+barrier cctype
barrier climits
barrier cmath
barrier compare
barrier concepts
barrier cstddef
barrier cstdint
+barrier cstdio
barrier cstdlib
barrier cstring
barrier ctime
+barrier cwchar
+barrier cwctype
barrier exception
barrier initializer_list
barrier iosfwd
@@ -945,6 +949,22 @@ future utility
future variant
future vector
future version
+generator cmath
+generator compare
+generator cstddef
+generator cstdint
+generator cstdlib
+generator cstring
+generator exception
+generator initializer_list
+generator iosfwd
+generator limits
+generator new
+generator tuple
+generator type_traits
+generator typeinfo
+generator utility
+generator version
initializer_list cstddef
initializer_list version
iomanip algorithm
@@ -2032,6 +2052,7 @@ stdexcept new
stdexcept type_traits
stdexcept typeinfo
stdexcept version
+stop_token cstddef
stop_token iosfwd
stop_token version
streambuf algorithm
diff --git a/libcxx/test/libcxx/transitive_includes/cxx14.csv b/libcxx/test/libcxx/transitive_includes/cxx14.csv
index c2eb5b44e8d7a..c31b86c5f8739 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx14.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx14.csv
@@ -125,15 +125,19 @@ atomic ratio
atomic type_traits
atomic version
barrier atomic
+barrier cctype
barrier climits
barrier cmath
barrier compare
barrier concepts
barrier cstddef
barrier cstdint
+barrier cstdio
barrier cstdlib
barrier cstring
barrier ctime
+barrier cwchar
+barrier cwctype
barrier exception
barrier initializer_list
barrier iosfwd
@@ -968,6 +972,22 @@ future utility
future variant
future vector
future version
+generator cmath
+generator compare
+generator cstddef
+generator cstdint
+generator cstdlib
+generator cstring
+generator exception
+generator initializer_list
+generator iosfwd
+generator limits
+generator new
+generator tuple
+generator type_traits
+generator typeinfo
+generator utility
+generator version
initializer_list cstddef
initializer_list version
iomanip algorithm
@@ -2072,6 +2092,7 @@ stdexcept new
stdexcept type_traits
stdexcept typeinfo
stdexcept version
+stop_token cstddef
stop_token iosfwd
stop_token version
streambuf algorithm
diff --git a/libcxx/test/libcxx/transitive_includes/cxx17.csv b/libcxx/test/libcxx/transitive_includes/cxx17.csv
index 332cb62f35b5f..50f2d9cf2ac5f 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx17.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx17.csv
@@ -122,15 +122,19 @@ atomic ratio
atomic type_traits
atomic version
barrier atomic
+barrier cctype
barrier climits
barrier cmath
barrier compare
barrier concepts
barrier cstddef
barrier cstdint
+barrier cstdio
barrier cstdlib
barrier cstring
barrier ctime
+barrier cwchar
+barrier cwctype
barrier exception
barrier initializer_list
barrier iosfwd
@@ -971,6 +975,22 @@ future utility
future variant
future vector
future version
+generator cmath
+generator compare
+generator cstddef
+generator cstdint
+generator cstdlib
+generator cstring
+generator exception
+generator initializer_list
+generator iosfwd
+generator limits
+generator new
+generator tuple
+generator type_traits
+generator typeinfo
+generator utility
+generator version
initializer_list cstddef
initializer_list version
iomanip algorithm
@@ -2085,6 +2105,7 @@ stdexcept new
stdexcept type_traits
stdexcept typeinfo
stdexcept version
+stop_token cstddef
stop_token iosfwd
stop_token version
streambuf algorithm
diff --git a/libcxx/test/libcxx/transitive_includes/cxx20.csv b/libcxx/test/libcxx/transitive_includes/cxx20.csv
index 55c79acff5a8f..0d23c92ec9a1d 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx20.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx20.csv
@@ -965,6 +965,22 @@ future utility
future variant
future vector
future version
+generator cmath
+generator compare
+generator cstddef
+generator cstdint
+generator cstdlib
+generator cstring
+generator exception
+generator initializer_list
+generator iosfwd
+generator limits
+generator new
+generator tuple
+generator type_traits
+generator typeinfo
+generator utility
+generator version
initializer_list cstddef
initializer_list version
iomanip algorithm
diff --git a/libcxx/test/libcxx/transitive_includes/cxx23.csv b/libcxx/test/libcxx/transitive_includes/cxx23.csv
index 073f698786117..2fde541964065 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx23.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx23.csv
@@ -466,6 +466,15 @@ future string_view
future tuple
future typeinfo
future version
+generator compare
+generator cstdint
+generator cstring
+generator initializer_list
+generator limits
+generator new
+generator tuple
+generator typeinfo
+generator version
initializer_list version
iomanip cctype
iomanip cerrno
diff --git a/libcxx/test/libcxx/transitive_includes/cxx26.csv b/libcxx/test/libcxx/transitive_includes/cxx26.csv
index d531d60ae3e35..5fde2907b3327 100644
--- a/libcxx/test/libcxx/transitive_includes/cxx26.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx26.csv
@@ -443,6 +443,15 @@ future string_view
future tuple
future typeinfo
future version
+generator compare
+generator cstdint
+generator cstring
+generator initializer_list
+generator limits
+generator new
+generator tuple
+generator typeinfo
+generator version
initializer_list version
iomanip cctype
iomanip cerrno
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/generator.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/generator.version.compile.pass.cpp
new file mode 100644
index 0000000000000..0726f4e59a553
--- /dev/null
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/generator.version.compile.pass.cpp
@@ -0,0 +1,65 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// WARNING: This test was generated by generate_feature_test_macro_components.py
+// and should not be edited manually.
+
+// <generator>
+
+// Test the feature test macros defined by <generator>
+
+// clang-format off
+
+#include <generator>
+#include "test_macros.h"
+
+#if TEST_STD_VER < 14
+
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
+#elif TEST_STD_VER == 14
+
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
+#elif TEST_STD_VER == 17
+
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
+#elif TEST_STD_VER == 20
+
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
+#elif TEST_STD_VER == 23
+
+# ifndef __cpp_lib_generator
+# error "__cpp_lib_generator should be defined in c++23"
+# endif
+# if __cpp_lib_generator != 202207L
+# error "__cpp_lib_generator should have the value 202207L in c++23"
+# endif
+
+#elif TEST_STD_VER > 23
+
+# ifndef __cpp_lib_generator
+# error "__cpp_lib_generator should be defined in c++26"
+# endif
+# if __cpp_lib_generator != 202207L
+# error "__cpp_lib_generator should have the value 202207L in c++26"
+# endif
+
+#endif // TEST_STD_VER > 23
+
+// clang-format on
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index 20c16700ef76a..32befec34ed09 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -412,6 +412,10 @@
# error "__cpp_lib_generate_random should not be defined before c++26"
# endif
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
# ifdef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should not be defined before c++14"
# endif
@@ -1351,6 +1355,10 @@
# error "__cpp_lib_generate_random should not be defined before c++26"
# endif
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
# ifndef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should be defined in c++14"
# endif
@@ -2413,6 +2421,10 @@
# error "__cpp_lib_generate_random should not be defined before c++26"
# endif
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
# ifndef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should be defined in c++17"
# endif
@@ -3742,6 +3754,10 @@
# error "__cpp_lib_generate_random should not be defined before c++26"
# endif
+# ifdef __cpp_lib_generator
+# error "__cpp_lib_generator should not be defined before c++23"
+# endif
+
# ifndef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should be defined in c++20"
# endif
@@ -5266,6 +5282,13 @@
# error "__cpp_lib_generate_random should not be defined before c++26"
# endif
+# ifndef __cpp_lib_generator
+# error "__cpp_lib_generator should be defined in c++23"
+# endif
+# if __cpp_lib_generator != 202207L
+# error "__cpp_lib_generator should have the value 202207L in c++23"
+# endif
+
# ifndef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should be defined in c++23"
# endif
@@ -7144,6 +7167,13 @@
# endif
# endif
+# ifndef __cpp_lib_generator
+# error "__cpp_lib_generator should be defined in c++26"
+# endif
+# if __cpp_lib_generator != 202207L
+# error "__cpp_lib_generator should have the value 202207L in c++26"
+# endif
+
# ifndef __cpp_lib_generic_associative_lookup
# error "__cpp_lib_generic_associative_lookup should be defined in c++26"
# endif
diff --git a/libcxx/test/std/ranges/coro.generator/allocator.pass.cpp b/libcxx/test/std/ranges/coro.generator/allocator.pass.cpp
new file mode 100644
index 0000000000000..96c2211ed3138
--- /dev/null
+++ b/libcxx/test/std/ranges/coro.generator/allocator.pass.cpp
@@ -0,0 +1,123 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++23
+
+// <generator>
+
+// template<class Ref, class Val = void, class Allocator = void>
+// class generator;
+
+#include <generator>
+
+#include <cassert>
+#include <cstddef>
+#include <memory>
+#include <memory_resource>
+#include <ranges>
+#include <utility>
+#include <vector>
+
+template <class T>
+class stateless_allocator {
+public:
+ using value_type = T;
+
+ stateless_allocator() noexcept = default;
+
+ template <typename U>
+ constexpr stateless_allocator(const stateless_allocator<U>&) noexcept {}
+
+ [[nodiscard]] T* allocate(size_t n) { return static_cast<T*>(::operator new(n * sizeof(T))); }
+
+ void deallocate(void* p, size_t) noexcept { ::operator delete(p); }
+
+ template <class U>
+ constexpr bool operator==(const stateless_allocator<U>&) const noexcept {
+ return true;
+ }
+};
+
+template <class T>
+class stateful_allocator {
+public:
+ using value_type = T;
+
+ stateful_allocator() noexcept = default;
+
+ template <typename U>
+ constexpr stateful_allocator(const stateful_allocator<U>&) noexcept {}
+
+ [[nodiscard]] T* allocate(size_t n) { return static_cast<T*>(::operator new(n * sizeof(T))); }
+
+ void deallocate(void* p, size_t) noexcept { ::operator delete(p); }
+
+ template <class U>
+ constexpr bool operator==(const stateful_allocator<U>& other) const noexcept {
+ return state_ == other.state_;
+ }
+
+private:
+ int state_ = 0;
+};
+
+template <class Allocator>
+bool test_with_allocator() {
+ std::vector<int> expected_fib_vec = {0, 1, 1, 2, 3};
+ {
+ auto fib = []() -> std::generator<int, int, Allocator> {
+ int a = 0;
+ int b = 1;
+ while (true) {
+ co_yield std::exchange(a, std::exchange(b, a + b));
+ }
+ };
+ assert((fib() | std::views::take(5) | std::ranges::to<std::vector>()) == expected_fib_vec);
+ }
+
+ {
+ auto fib = [](std::allocator_arg_t, Allocator) -> std::generator<int, int, Allocator> {
+ int a = 0;
+ int b = 1;
+ while (true) {
+ co_yield std::exchange(a, std::exchange(b, a + b));
+ }
+ };
+ assert((fib(std::allocator_arg, {}) | std::views::take(5) | std::ranges::to<std::vector>()) == expected_fib_vec);
+ }
+
+ {
+ auto fib = [](std::allocator_arg_t, Allocator) -> std::generator<int> {
+ int a = 0;
+ int b = 1;
+ while (true) {
+ co_yield std::exchange(a, std::exchange(b, a + b));
+ }
+ };
+ assert((fib(std::allocator_arg, {}) | std::views::take(5) | std::ranges::to<std::vector>()) == expected_fib_vec);
+ }
+ return true;
+}
+
+bool test() {
+ test_with_allocator<std::allocator<std::byte>>();
+ test_with_allocator<stateless_allocator<std::byte>>();
+ test_with_allocator<stateful_allocator<std::byte>>();
+ test_with_allocator<std::pmr::polymorphic_allocator<std::byte>>();
+
+ test_with_allocator<std::allocator<float>>();
+ test_with_allocator<stateless_allocator<float>>();
+ test_with_allocator<stateful_allocator<float>>();
+ test_with_allocator<std::pmr::polymorphic_allocator<float>>();
+ return true;
+};
+
+int main() {
+ test();
+ return 0;
+}
diff --git a/libcxx/test/std/ranges/coro.generator/generator.compile.pass.cpp b/libcxx/test/std/ranges/coro.generator/generator.compile.pass.cpp
new file mode 100644
index 0000000000000..769a56021c32b
--- /dev/null
+++ b/libcxx/test/std/ranges/coro.generator/generator.compile.pass.cpp
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++23
+
+// <generator>
+
+// template<class Ref, class Val = void, class Allocator = void>
+// class generator;
+
+#include <generator>
+
+#include <cassert>
+#include <concepts>
+#include <ranges>
+
+template <class G, class V, class R, class RR>
+constexpr bool conformance() {
+ static_assert(std::ranges::range<G>);
+ static_assert(std::ranges::view<G>);
+ static_assert(std::ranges::input_range<G>);
+ static_assert(!std::ranges::forward_range<G>);
+ static_assert(!std::ranges::borrowed_range<G>);
+
+ static_assert(std::same_as<std::ranges::range_value_t<G>, V>);
+ static_assert(std::same_as<std::ranges::range_reference_t<G>, R>);
+ static_assert(std::same_as<std::ranges::range_rvalue_reference_t<G>, RR>);
+
+ return true;
+}
+
+static_assert(conformance<std::generator<int>, int, int&&, int&&>());
+static_assert(conformance<std::generator<int, int>, int, int, int>());
+
+static_assert(conformance<std::generator<int&>, int, int&, int&&>());
+static_assert(conformance<std::generator<int&, int>, int, int&, int&&>());
+static_assert(conformance<std::generator<const int&>, int, const int&, const int&&>());
+static_assert(conformance<std::generator<const int&, int>, int, const int&, const int&&>());
+
+static_assert(conformance<std::generator<int&&>, int, int&&, int&&>());
+static_assert(conformance<std::generator<int&&, int>, int, int&&, int&&>());
+static_assert(conformance<std::generator<const int&&>, int, const int&&, const int&&>());
+static_assert(conformance<std::generator<const int&&, int>, int, const int&&, const int&&>());
diff --git a/libcxx/test/std/ranges/coro.generator/generator.pass.cpp b/libcxx/test/std/ranges/coro.generator/generator.pass.cpp
new file mode 100644
index 0000000000000..ed1793382962a
--- /dev/null
+++ b/libcxx/test/std/ranges/coro.generator/generator.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++23
+
+// <generator>
+
+// template<class Ref, class Val = void, class Allocator = void>
+// class generator;
+
+#include <generator>
+
+#include <cassert>
+#include <ranges>
+#include <utility>
+#include <vector>
+
+std::generator<int> fib() {
+ int a = 0;
+ int b = 1;
+ while (true) {
+ co_yield std::exchange(a, std::exchange(b, a + b));
+ }
+}
+
+std::generator<const int&> range_fib() {
+ co_yield std::ranges::elements_of(std::vector<int>{0, 1});
+ co_yield std::ranges::elements_of(std::vector<int>{1, 2});
+ co_yield std::ranges::elements_of(std::vector<int>{3, 5});
+ co_yield std::ranges::elements_of(std::vector<int>{5, 8});
+}
+
+bool test() {
+ {
+ std::vector<int> expected_fib_vec = {0, 1, 1, 2, 3};
+ {
+ auto fib_vec = fib() | std::views::take(5) | std::ranges::to<std::vector<int>>();
+ assert(fib_vec == expected_fib_vec);
+ }
+ {
+ auto fib_vec = range_fib() | std::views::take(5) | std::ranges::to<std::vector<int>>();
+ assert(fib_vec == expected_fib_vec);
+ }
+ }
+ return true;
+}
+
+int main() {
+ test();
+ return 0;
+}
diff --git a/libcxx/test/std/ranges/coro.generator/recursive.pass.cpp b/libcxx/test/std/ranges/coro.generator/recursive.pass.cpp
new file mode 100644
index 0000000000000..36c5b8b65e42e
--- /dev/null
+++ b/libcxx/test/std/ranges/coro.generator/recursive.pass.cpp
@@ -0,0 +1,97 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++23
+
+// <generator>
+
+// template<class Ref, class Val = void, class Allocator = void>
+// class generator;
+
+#include <generator>
+
+#include <cassert>
+#include <numeric>
+#include <ranges>
+#include <utility>
+#include <vector>
+
+std::generator<int> fib() {
+ int a = 0;
+ int b = 1;
+ while (true) {
+ co_yield std::exchange(a, std::exchange(b, a + b));
+ }
+}
+
+std::generator<int> recursive_fib(int depth) {
+ if (depth == 0) {
+ co_yield std::ranges::elements_of(fib());
+ } else {
+ co_yield std::ranges::elements_of(recursive_fib(depth - 1));
+ }
+};
+
+struct tree_node {
+ tree_node* left;
+ tree_node* right;
+ int element;
+
+ ~tree_node() {
+ delete left;
+ delete right;
+ }
+};
+
+tree_node* build_tree(int depth) {
+ if (depth == 0) {
+ return nullptr;
+ }
+
+ tree_node* root = new tree_node();
+ root->element = depth;
+ root->left = build_tree(depth - 1);
+ root->right = build_tree(depth - 1);
+ return root;
+}
+
+std::generator<int> traversal(tree_node* node) {
+ if (node == nullptr) {
+ co_return;
+ }
+ co_yield std::ranges::elements_of(traversal(node->left));
+ co_yield node->element;
+ co_yield std::ranges::elements_of(traversal(node->right));
+}
+
+bool test() {
+ {
+ std::vector<int> expected_fib_vec = {0, 1, 1, 2, 3};
+ {
+ auto fib_vec = recursive_fib(1) | std::views::take(5) | std::ranges::to<std::vector<int>>();
+ assert(fib_vec == expected_fib_vec);
+ }
+ {
+ auto fib_vec = recursive_fib(42) | std::views::take(5) | std::ranges::to<std::vector<int>>();
+ assert(fib_vec == expected_fib_vec);
+ }
+ }
+ {
+ tree_node* tree_root = build_tree(10);
+ auto node_vec = traversal(tree_root) | std::ranges::to<std::vector<int>>();
+ assert(node_vec.size() == 1023);
+ assert(std::reduce(node_vec.cbegin(), node_vec.cend()) == 2036);
+ delete tree_root;
+ }
+ return true;
+}
+
+int main() {
+ test();
+ return 0;
+}
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index d8fb575b97b2f..a5db6f1f1650f 100644
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -719,6 +719,11 @@ def add_version_header(tc):
"headers": ["random"],
"unimplemented": True,
},
+ {
+ "name": "__cpp_lib_generator",
+ "values": {"c++23": 202207}, # P2502R2: std::generator: Synchronous Coroutine Generator for Ranges
+ "headers": ["generator"],
+ },
{
"name": "__cpp_lib_generic_associative_lookup",
"values": {"c++14": 201304},
diff --git a/libcxx/utils/libcxx/header_information.py b/libcxx/utils/libcxx/header_information.py
index d06271a7908cc..cc33d32a69201 100644
--- a/libcxx/utils/libcxx/header_information.py
+++ b/libcxx/utils/libcxx/header_information.py
@@ -164,7 +164,6 @@ def __hash__(self) -> int:
# modules will fail to build if a header is added but this list is not updated.
headers_not_available = list(map(Header, [
"debugging",
- "generator",
"hazard_pointer",
"inplace_vector",
"linalg",
>From f2ee26c784c91829799073fe12d1cbd0d281a755 Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Fri, 5 Jun 2026 22:52:35 +0800
Subject: [PATCH 2/3] release notes & python format
---
libcxx/docs/ReleaseNotes/23.rst | 2 ++
libcxx/utils/generate_feature_test_macro_components.py | 4 +++-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/libcxx/docs/ReleaseNotes/23.rst b/libcxx/docs/ReleaseNotes/23.rst
index 03dabc54dcf79..a53fad86004a6 100644
--- a/libcxx/docs/ReleaseNotes/23.rst
+++ b/libcxx/docs/ReleaseNotes/23.rst
@@ -51,6 +51,8 @@ Implemented Papers
- P2542R8: ``views::concat`` (`Github <https://llvm.org/PR105419>`__)
- P3383R3: ``mdspan.at()`` (`Github <https://llvm.org/PR175213>`__)
- P3508R0: Wording for "constexpr for specialized memory algorithms" (`Github <https://llvm.org/PR118379>`__)
+- P2502R2: ``std::generator``: Synchronous Coroutine Generator for Ranges (`Github <https://llvm.org/PR105226>`__)
+- P2787R1: ``pmr::generator`` - Promise Types are not Values (`Github <https://llvm.org/PR105263>`__)
Improvements and New Features
-----------------------------
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index a5db6f1f1650f..ea2e43b4c15a8 100644
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -721,7 +721,9 @@ def add_version_header(tc):
},
{
"name": "__cpp_lib_generator",
- "values": {"c++23": 202207}, # P2502R2: std::generator: Synchronous Coroutine Generator for Ranges
+ "values": {
+ "c++23": 202207
+ }, # P2502R2: std::generator: Synchronous Coroutine Generator for Ranges
"headers": ["generator"],
},
{
>From 19e5608ff21db2369e7172201d55bc372e48d67b Mon Sep 17 00:00:00 2001
From: c8ef <c8ef at outlook.com>
Date: Fri, 5 Jun 2026 23:27:41 +0800
Subject: [PATCH 3/3] test
---
libcxx/include/generator | 109 +++++++++++++++++++++------------------
1 file changed, 60 insertions(+), 49 deletions(-)
diff --git a/libcxx/include/generator b/libcxx/include/generator
index d3f942b089002..7792b65a6ae43 100644
--- a/libcxx/include/generator
+++ b/libcxx/include/generator
@@ -25,52 +25,56 @@ namespace std {
*/
-#include <__algorithm/max.h>
-#include <__assert>
-#include <__concepts/common_reference_with.h>
-#include <__concepts/constructible.h>
-#include <__concepts/convertible_to.h>
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__coroutine/coroutine_handle.h>
-#include <__coroutine/coroutine_traits.h>
-#include <__coroutine/noop_coroutine_handle.h>
-#include <__coroutine/trivial_awaitables.h>
-#include <__exception/exception_ptr.h>
-#include <__iterator/default_sentinel.h>
-#include <__memory/addressof.h>
-#include <__memory/allocator_arg_t.h>
-#include <__memory/allocator_traits.h>
-#include <__memory/construct_at.h>
-#include <__memory_resource/polymorphic_allocator.h>
-#include <__ranges/access.h>
-#include <__ranges/concepts.h>
-#include <__ranges/elements_of.h>
-#include <__ranges/view_interface.h>
-#include <__type_traits/add_pointer.h>
-#include <__type_traits/common_reference.h>
-#include <__type_traits/conditional.h>
-#include <__type_traits/is_nothrow_constructible.h>
-#include <__type_traits/is_object.h>
-#include <__type_traits/is_pointer.h>
-#include <__type_traits/is_reference.h>
-#include <__type_traits/is_void.h>
-#include <__type_traits/remove_cvref.h>
-#include <__type_traits/remove_reference.h>
-#include <__utility/exchange.h>
-#include <__utility/move.h>
-#include <__utility/swap.h>
-#include <cstdint>
-#include <new>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-# pragma GCC system_header
-#endif
+#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
+# include <__cxx03/__config>
+#else
+# include <__config>
+
+# if _LIBCPP_STD_VER >= 23
+
+# include <__algorithm/max.h>
+# include <__assert>
+# include <__concepts/common_reference_with.h>
+# include <__concepts/constructible.h>
+# include <__concepts/convertible_to.h>
+# include <__concepts/same_as.h>
+# include <__coroutine/coroutine_handle.h>
+# include <__coroutine/coroutine_traits.h>
+# include <__coroutine/noop_coroutine_handle.h>
+# include <__coroutine/trivial_awaitables.h>
+# include <__exception/exception_ptr.h>
+# include <__iterator/default_sentinel.h>
+# include <__memory/addressof.h>
+# include <__memory/allocator_arg_t.h>
+# include <__memory/allocator_traits.h>
+# include <__memory/construct_at.h>
+# include <__memory_resource/polymorphic_allocator.h>
+# include <__ranges/access.h>
+# include <__ranges/concepts.h>
+# include <__ranges/elements_of.h>
+# include <__ranges/view_interface.h>
+# include <__type_traits/add_pointer.h>
+# include <__type_traits/common_reference.h>
+# include <__type_traits/conditional.h>
+# include <__type_traits/is_nothrow_constructible.h>
+# include <__type_traits/is_object.h>
+# include <__type_traits/is_pointer.h>
+# include <__type_traits/is_reference.h>
+# include <__type_traits/is_void.h>
+# include <__type_traits/remove_cvref.h>
+# include <__type_traits/remove_reference.h>
+# include <__utility/exchange.h>
+# include <__utility/move.h>
+# include <__utility/swap.h>
+# include <cstdint>
+# include <new>
+
+# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+# endif
_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#if _LIBCPP_STD_VER >= 23
+# include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -309,13 +313,13 @@ public:
_LIBCPP_HIDE_FROM_ABI void return_void() const noexcept {}
_LIBCPP_HIDE_FROM_ABI void unhandled_exception() {
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
if (__is_root()) {
throw;
} else {
__get_recursive_data().__exception = std::current_exception();
}
-# endif
+# endif
}
};
@@ -462,9 +466,14 @@ private:
public:
_LIBCPP_HIDE_FROM_ABI void* operator new(size_t __size) {
- void* const __ptr = ::operator new(__size + sizeof(__dealloc_fn));
- __dealloc_fn __dealloc = [](void* const __dealloc_ptr, const size_t __dealloc_size) static noexcept -> void {
+ void* const __ptr = ::operator new(__size + sizeof(__dealloc_fn));
+ __dealloc_fn __dealloc =
+ [](void* const __dealloc_ptr, [[maybe_unused]] const size_t __dealloc_size) static noexcept -> void {
+# ifdef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
+ ::operator delete(__dealloc_ptr);
+# else
::operator delete(__dealloc_ptr, __dealloc_size + sizeof(__dealloc_fn));
+# endif
};
__dealloc_fn* const __dealloc_ptr = reinterpret_cast<__dealloc_fn*>(reinterpret_cast<uintptr_t>(__ptr) + __size);
@@ -596,8 +605,10 @@ using generator = std::generator<_Ref, _Val, polymorphic_allocator<>>;
_LIBCPP_END_NAMESPACE_STD
-#endif // _LIBCPP_STD_VER >= 23
+# endif // _LIBCPP_STD_VER >= 23
_LIBCPP_POP_MACROS
+#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
+
#endif // _LIBCPP_GENERATOR
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