libc++ C++2c Status

Overview

In June 2023, the C++ standard committee adopted the first changes to the next version of the C++ standard, known here as “C++2c” (probably to be C++26).

This page shows the status of libc++; the status of clang’s support of the language features is here.

Attention

Features in unreleased drafts of the standard are subject to change.

The groups that have contributed papers:

• CWG - Core Language Working group

• LWG - Library working group

• SG1 - Study group #1 (Concurrency working group)

Note

“Nothing to do” means that no library changes were needed to implement this change.

Paper Status

Paper #	Paper Name	Meeting	Status	First released version	GitHub issue	Notes
P2497R0	Testing for success or failure of <charconv> functions	2023-06 (Varna)	Complete	18	#105357
P2592R3	Hashing support for std::chrono value classes	2023-06 (Varna)			#105358
P2587R3	to_string or not to_string	2023-06 (Varna)			#105359
P2562R1	constexpr Stable Sorting	2023-06 (Varna)	Complete	21	#105360
P2545R4	Read-Copy Update (RCU)	2023-06 (Varna)			#105361
P2530R3	Hazard Pointers for C++26	2023-06 (Varna)			#105362
P2538R1	ADL-proof std::projected	2023-06 (Varna)	Complete	18	#105363
P2495R3	Interfacing stringstreams with string_view	2023-06 (Varna)	Complete	19	#105364
P2510R3	Formatting pointers	2023-06 (Varna)	Complete	17	#105365	Implemented as a DR against C++20. (MSVC STL and libstdc++ will do the same.)
P2198R7	Freestanding Feature-Test Macros and Implementation-Defined Extensions	2023-06 (Varna)			#105368
P2338R4	Freestanding Library: Character primitives and the C library	2023-06 (Varna)			#105369
P2013R5	Freestanding Language: Optional ::operator new	2023-06 (Varna)			#105370
P2363R5	Extending associative containers with the remaining heterogeneous overloads	2023-06 (Varna)			#105371
P1901R2	Enabling the Use of weak_ptr as Keys in Unordered Associative Containers	2023-06 (Varna)			#105372
P1885R12	Naming Text Encodings to Demystify Them	2023-06 (Varna)			#105373
P0792R14	function_ref: a type-erased callable reference	2023-06 (Varna)			#105376
P2874R2	P2874R2: Mandating Annex D Require No More	2023-06 (Varna)	Complete	12	#105377
P2757R3	Type-checking format args	2023-06 (Varna)			#105378
P2637R3	Member visit	2023-06 (Varna)	Complete	19	#105380	Change of __cpp_lib_variant is completed in LLVM 20. Change of __cpp_lib_format is blocked by P2419R2.
P2641R4	Checking if a union alternative is active	2023-06 (Varna)	Complete	22	#105381
P1759R6	Native handles and file streams	2023-06 (Varna)	Complete	18	#105382
P2697R1	Interfacing bitset with string_view	2023-06 (Varna)	Complete	18	#105384
P1383R2	More constexpr for <cmath> and <complex>	2023-06 (Varna)			#105385
P2734R0	Adding the new SI prefixes	2023-06 (Varna)	Complete	17	#105386
P2548R6	copyable_function	2023-06 (Varna)			#105387
P2714R1	Bind front and back to NTTP callables	2023-06 (Varna)	Partial	20	#105388
P2630R4	submdspan	2023-06 (Varna)			#105389
P0543R3	Saturation arithmetic	2023-11 (Kona)	Complete	18	#105390
P2407R5	Freestanding Library: Partial Classes	2023-11 (Kona)			#105391
P2546R5	Debugging Support	2023-11 (Kona)			#105392
P2905R2	Runtime format strings	2023-11 (Kona)	Complete	18	#105393
P2918R2	Runtime format strings II	2023-11 (Kona)	Complete	18	#105394
P2909R4	Fix formatting of code units as integers (Dude, where’s my char?)	2023-11 (Kona)	Complete	18	#105395
P0952R2	A new specification for std::generate_canonical	2023-11 (Kona)			#105396
P2447R6	std::span over an initializer list	2023-11 (Kona)	Complete	18	#105397
P2821R5	span.at()	2023-11 (Kona)	Complete	18	#105399
P2868R3	Remove Deprecated std::allocator Typedef From C++26	2023-11 (Kona)	Complete	18	#105400
P2870R3	Remove basic_string::reserve() From C++26	2023-11 (Kona)	Complete	18	#105401
P2871R3	Remove Deprecated Unicode Conversion Facets from C++26	2023-11 (Kona)	Complete	18	#105402
P2819R2	Add tuple protocol to complex	2023-11 (Kona)	Complete	19	#105403
P2937R0	Freestanding: Remove strtok	2023-11 (Kona)			#105404
P2833R2	Freestanding Library: inout expected span	2023-11 (Kona)			#105405
P2836R1	std::basic_const_iterator should follow its underlying type’s convertibility	2023-11 (Kona)			#105406
P2264R7	Make assert() macro user friendly for C and C++	2023-11 (Kona)			#105407
P1673R13	A free function linear algebra interface based on the BLAS	2023-11 (Kona)			#105408
P2875R4	Undeprecate polymorphic_allocator::destroy for C++26	2024-03 (Tokyo)	Complete	15	#105410
P2867R2	Remove Deprecated strstreams From C++26	2024-03 (Tokyo)	Complete	19	#105411
P2869R4	Remove Deprecated shared_ptr Atomic Access APIs from C++26	2024-03 (Tokyo)			#105412
P2872R3	Remove wstring_convert From C++26	2024-03 (Tokyo)	Complete	19	#105413
P3107R5	Permit an efficient implementation of std::print	2024-03 (Tokyo)			#105414
P3142R0	Printing Blank Lines with println	2024-03 (Tokyo)	Complete	19	#105415	Implemented as a DR against C++23. (MSVC STL and libstdc++ will do the same.)
P2845R8	Formatting of std::filesystem::path	2024-03 (Tokyo)			#105416
P0493R5	Atomic minimum/maximum	2024-03 (Tokyo)			#105418
P2542R8	views::concat	2024-03 (Tokyo)			#105419
P2591R5	Concatenation of strings and string views	2024-03 (Tokyo)	Complete	19	#105420
P2248R8	Enabling list-initialization for algorithms	2024-03 (Tokyo)			#105421
P2810R4	is_debugger_present is_replaceable	2024-03 (Tokyo)			#105422
P1068R11	Vector API for random number generation	2024-03 (Tokyo)			#105423
P2944R3	Comparisons for reference_wrapper	2024-03 (Tokyo)	Complete	22	#105424	The changes to tuple’s equality overload from P2165R4 are not yet implemented.
P2642R6	Padded mdspan layouts	2024-03 (Tokyo)			#105425
P3029R1	Better mdspan’s CTAD	2024-03 (Tokyo)	Complete	19	#105426
P2747R2	constexpr placement new	2024-06 (St. Louis)	Complete	20	#105427
P2997R1	Removing the common reference requirement from the indirectly invocable concepts	2024-06 (St. Louis)	Complete	19	#105428	Implemented as a DR against C++20. (MSVC STL and libstdc++ will do the same.)
P2389R2	dextents Index Type Parameter	2024-06 (St. Louis)	Complete	19	#105429
P3168R2	Give std::optional Range Support	2024-06 (St. Louis)	Complete	22	#105430
P3217R0	Adjoints to ‘Enabling list-initialization for algorithms’: find_last	2024-06 (St. Louis)			#105431
P2985R0	A type trait for detecting virtual base classes	2024-06 (St. Louis)	Complete	20	#105432
P0843R14	inplace_vector	2024-06 (St. Louis)			#105433
P3235R3	std::print more types faster with less memory	2024-06 (St. Louis)			#105435
P2968R2	Make std::ignore a first-class object	2024-06 (St. Louis)	Complete	19	#105436
P2075R6	Philox as an extension of the C++ RNG engines	2024-06 (St. Louis)			#105437
P2422R1	Remove nodiscard annotations from the standard library specification	2024-06 (St. Louis)	Complete	19	#105438	nodiscard attributes were kept as a conforming extension
P2300R10	std::execution	2024-06 (St. Louis)			#105440
P3136R1	Retiring niebloids	2024-11 (Wrocław)	Complete	14	#118133
P3138R5	views::cache_latest	2024-11 (Wrocław)			#118134
P3379R0	Constrain std::expected equality operators	2024-11 (Wrocław)	Complete	21	#118135
P2862R1	text_encoding::name() should never return null values	2024-11 (Wrocław)			#118371
P2897R7	aligned_accessor: An mdspan accessor expressing pointer over-alignment	2024-11 (Wrocław)	Complete	21	#118372
P3355R2	Fix submdspan for C++26	2024-11 (Wrocław)			#118373
P3222R0	Fix C++26 by adding transposed special cases for P2642 layouts	2024-11 (Wrocław)			#118374
P3050R2	Fix C++26 by optimizing linalg::conjugated for noncomplex value types	2024-11 (Wrocław)			#118375
P3396R1	std::execution wording fixes	2024-11 (Wrocław)			#118376
P2835R7	Expose std::atomic_ref’s object address	2024-11 (Wrocław)	Complete	22	#118377
P3323R1	cv-qualified types in atomic and atomic_ref	2024-11 (Wrocław)			#118378
P3508R0	Wording for “constexpr for specialized memory algorithms”	2024-11 (Wrocław)			#118379
P3369R0	constexpr for uninitialized_default_construct	2024-11 (Wrocław)			#118380
P3370R1	Add new library headers from C23	2024-11 (Wrocław)			#118381
P3309R3	constexpr atomic and atomic_ref	2024-11 (Wrocław)			#118382
P1928R15	std::simd — merge data-parallel types from the Parallelism TS 2	2024-11 (Wrocław)			#118384
P3325R5	A Utility for Creating Execution Environments	2024-11 (Wrocław)			#118385
P3068R6	Allowing exception throwing in constant-evaluation	2024-11 (Wrocław)			#118386
P3247R2	Deprecate the notion of trivial types	2024-11 (Wrocław)	Complete	21	#118387
P3074R7	trivial unions (was std::uninitialized)	2025-02 (Hagenberg)			#127868
P1494R5	Partial program correctness	2025-02 (Hagenberg)			#127869
P2900R14	Contracts for C++	2025-02 (Hagenberg)			#127870
P3475R2	Defang and deprecate memory_order::consume	2025-02 (Hagenberg)			#127871
P2786R13	Trivial Relocatability For C++26	2025-02 (Hagenberg)			#127872
P3137R3	views::to_input	2025-02 (Hagenberg)			#127873
P0472R3	Put std::monostate in <utility>	2025-02 (Hagenberg)	Complete	21	#127874
P3349R1	Converting contiguous iterators to pointers	2025-02 (Hagenberg)			#127875
P3372R3	constexpr containers and adaptors	2025-02 (Hagenberg)	In Progress		#127876
P3378R2	constexpr exception types	2025-02 (Hagenberg)			#127877
P3441R2	Rename simd_split to simd_chunk	2025-02 (Hagenberg)			#127878
P3287R3	Exploration of namespaces for std::simd	2025-02 (Hagenberg)			#127879
P2976R1	Freestanding Library: algorithm, numeric, and random	2025-02 (Hagenberg)			#127880
P3430R3	simd issues: explicit, unsequenced, identity-element position, and members of disabled simd	2025-02 (Hagenberg)			#127881
P2663R7	Interleaved complex values support in std::simd	2025-02 (Hagenberg)			#127882
P2933R4	Extend <bit> header function with overloads for std::simd	2025-02 (Hagenberg)			#127883
P2846R6	reserve_hint: Eagerly reserving memory for not-quite-sized lazy ranges	2025-02 (Hagenberg)			#127884
P3471R4	Standard Library Hardening	2025-02 (Hagenberg)			#127885
P0447R28	Introduction of std::hive to the standard library	2025-02 (Hagenberg)			#127886
P3019R14	indirect and polymorphic: Vocabulary Types for Composite Class Design	2025-02 (Hagenberg)			#127887
P2996R13	Reflection for C++26	2025-06 (Sofia)			#148123
P3394R4	Annotations for Reflection	2025-06 (Sofia)			#148124
P3293R3	Splicing a base class subobject	2025-06 (Sofia)			#148125
P3491R3	define_static_{string,object,array}	2025-06 (Sofia)			#148126
P3096R12	Function Parameter Reflection in Reflection for C++26	2025-06 (Sofia)			#148127
P2988R12	std::optional<T&>	2025-06 (Sofia)	Complete	22	#148131
P3348R4	C++26 should refer to C23 not C17	2025-06 (Sofia)			#148133
P3037R6	constexpr std::shared_ptr and friends	2025-06 (Sofia)			#148135
P3284R4	write_env and unstoppable Sender Adaptors	2025-06 (Sofia)			#148136
P3179R9	Parallel Range Algorithms	2025-06 (Sofia)			#148137
P3709R2	Reconsider parallel ranges::rotate_copy and ranges::reverse_copy	2025-06 (Sofia)			#148138
P3641R0	Rename std::observable to std::observable_checkpoint, and add a feature-test macro	2025-06 (Sofia)			#148139
P3044R2	sub-string_view from string	2025-06 (Sofia)	Complete	22	#148140
P2876R3	Proposal to extend std::simd with more constructors and accessors	2025-06 (Sofia)			#148143
P3480R6	std::simd is a range	2025-06 (Sofia)			#148144
P2664R11	Extend std::simd with permutation API	2025-06 (Sofia)			#148145
P3691R1	Reconsider naming of the namespace for std::simd	2025-06 (Sofia)			#148148
P3383R3	mdspan.at()	2025-06 (Sofia)			#148149
P2927R3	Inspecting exception_ptr	2025-06 (Sofia)			#148150
P3748R0	Inspecting exception_ptr should be constexpr	2025-06 (Sofia)			#148151
P2830R10	Standardized Constexpr Type Ordering	2025-06 (Sofia)			#148152
P3570R2	optional variants in sender/receiver	2025-06 (Sofia)			#148153
P3481R5	std::execution::bulk() issues	2025-06 (Sofia)			#148155
P3433R1	Allocator Support for Operation States	2025-06 (Sofia)			#148157
P3149R11	async_scope - Creating scopes for non-sequential concurrency	2025-06 (Sofia)			#148158
P3682R0	Remove std::execution::split	2025-06 (Sofia)			#148160
P2079R10	Parallel scheduler	2025-06 (Sofia)			#148161
P3557R3	High-Quality Sender Diagnostics with Constexpr Exceptions	2025-06 (Sofia)			#148162
P3560R2	Error Handling in Reflection	2025-06 (Sofia)			#148128
P3503R3	Make type-erased allocator use in promise and packaged_task consistent	2025-06 (Sofia)			#148164
P3008R6	Atomic floating-point min/max	2025-06 (Sofia)			#148168
P3111R8	Atomic Reduction Operations	2025-06 (Sofia)			#148174
P3060R3	Add std::views::indices(n)	2025-06 (Sofia)	Complete	22	#148175
P2319R5	Prevent path presentation problems	2025-06 (Sofia)			#148177
P3223R2	Making std::istream::ignore less surprising	2025-06 (Sofia)	Complete	22	#148178
P2781R9	std::constant_wrapper	2025-06 (Sofia)			#148179
P3697R1	Minor additions to C++26 standard library hardening	2025-06 (Sofia)			#148180
P3552R3	Add a Coroutine Task Type	2025-06 (Sofia)			#148182
P1317R2	Remove return type deduction in std::apply	2025-06 (Sofia)			#148183
P3920R0	Wording for NB comment resolution on trivial relocation	2025-11 (Kona)			#171269
P3016R6	Resolve inconsistencies in begin/end for valarray and braced initializer lists	2025-11 (Kona)			#171271
P3567R2	flat_meow Fixes	2025-11 (Kona)	Complete	22	#171272
P3663R3	Future-proof submdspan_mapping	2025-11 (Kona)			#166089
P3914R0	Assorted NB comment resolutions for Kona 2025	2025-11 (Kona)			#171274
P3836R2	Make optional<T&> trivially copyable	2025-11 (Kona)			#171275
P3860R1	Proposed Resolution for NB Comment GB13-309 atomic_ref<T> is not convertible to atomic_ref<const T>	2025-11 (Kona)			#171276
P3388R3	When Do You Know connect Doesn’t Throw?	2025-11 (Kona)			#171277
P3774R1	Rename std::nontype, and make it broadly useful	2025-11 (Kona)			#171279
P3819R0	Remove evaluation_exception() from contract-violation handling for C++26	2025-11 (Kona)			#171280
P3612R1	Harmonize proxy-reference operations (LWG 3638 and 4187)	2025-11 (Kona)			#171281
P3778R0	Fix for type_order template definition	2025-11 (Kona)			#171284
P1789R3	Library Support for Expansion Statements	2025-11 (Kona)			#167268
P3922R1	Missing deduction guide from simd::mask to simd::vec	2025-11 (Kona)			#171285
P3878R1	Standard library hardening should not use the ‘observe’ semantic	2025-11 (Kona)			#171286
P3887R1	Make when_all a Ronseal Algorithm	2025-11 (Kona)			#171289
P3923R0	Additional NB comment resolutions for Kona 2025	2025-11 (Kona)			#171290
P3371R5	Fix C++26 by making the rank-1, rank-2, rank-k, and rank-2k updates consistent with the BLAS	2025-11 (Kona)			#171291
P3391R2	constexpr std::format	2025-11 (Kona)			#171292
P3913R1	Optimize for std::optional in range adaptors	2025-11 (Kona)			#171294

Library Working Group Issues Status

Issue #	Issue Name	Meeting	Status	First released version	GitHub issue	Notes
LWG2994	Needless UB for basic_string and basic_string_view	2023-06 (Varna)	Complete	5	#105268
LWG3884	flat_foo is missing allocator-extended copy/move constructors	2023-06 (Varna)			#105269
LWG3885	op should be in [zombie.names]	2023-06 (Varna)	Nothing To Do		#105270
LWG3887	Version macro for allocate_at_least	2023-06 (Varna)	Complete	19	#105271
LWG3893	LWG 3661 broke atomic<shared_ptr<T>> a; a = nullptr;	2023-06 (Varna)			#105273
LWG3894	generator::promise_type::yield_value(ranges::elements_of<Rng, Alloc>) should not be noexcept	2023-06 (Varna)			#105274
LWG3903	span destructor is redundantly noexcept	2023-06 (Varna)	Complete	7	#105275
LWG3904	lazy_split_view::outer-iterator’s const-converting constructor isn’t setting trailing_empty_	2023-06 (Varna)			#105276
LWG3905	Type of std::fexcept_t	2023-06 (Varna)	Complete	3.4	#105277
LWG3912	enumerate_view::iterator::operator- should be noexcept	2023-06 (Varna)			#105279
LWG3914	Inconsistent template-head of ranges::enumerate_view	2023-06 (Varna)			#105280
LWG3915	Redundant paragraph about expression variations	2023-06 (Varna)			#105281
LWG3925	Concept formattable’s definition is incorrect	2023-06 (Varna)	Complete	17	#105282
LWG3927	Unclear preconditions for operator[] for sequence containers	2023-06 (Varna)	Nothing To Do		#105283
LWG3935	template<class X> constexpr complex& operator=(const complex<X>&) has no specification	2023-06 (Varna)	Complete	3.4	#105284
LWG3938	Cannot use std::expected monadic ops with move-only error_type	2023-06 (Varna)	Complete	18	#105285
LWG3940	std::expected<void, E>::value() also needs E to be copy constructible	2023-06 (Varna)	Complete	18	#105286
LWG2392	“character type” is used but not defined	2023-11 (Kona)			#105287
LWG3203	span element access invalidation	2023-11 (Kona)	Nothing To Do		#105288
LWG3305	any_cast<void>	2023-11 (Kona)	Complete	18	#105289
LWG3431	<=> for containers should require three_way_comparable<T> instead of <=>	2023-11 (Kona)			#105290
LWG3749	common_iterator should handle integer-class difference types	2023-11 (Kona)			#105291
LWG3809	Is std::subtract_with_carry_engine<uint16_t> supposed to work	2023-11 (Kona)			#105295
LWG3892	Incorrect formatting of nested ranges and tuples	2023-11 (Kona)	Complete	17	#105296
LWG3897	inout_ptr will not update raw pointer to 0	2023-11 (Kona)	Complete	19	#105297
LWG3946	The definition of const_iterator_t should be reworked	2023-11 (Kona)			#105298
LWG3947	Unexpected constraints on adjacent_transform_view::base()	2023-11 (Kona)			#105299
LWG3948	possibly-const-range and as-const-pointer should be noexcept	2023-11 (Kona)			#105300
LWG3949	std::atomic<bool>’s trivial destructor dropped in C++17 spec wording	2023-11 (Kona)			#105301
LWG3951	[expected.object.swap]: Using value() instead of has_value()	2023-11 (Kona)	Complete	16	#105302
LWG3953	iter_move for common_iterator and counted_iterator should return decltype(auto)	2023-11 (Kona)	Complete	20	#105303
LWG3957	[container.alloc.reqmts] The value category of v should be claimed	2023-11 (Kona)			#105304
LWG3965	Incorrect example in [format.string.escaped] p3 for formatting of combining characters	2023-11 (Kona)	Complete	19	#105305
LWG3970	[mdspan.syn] Missing definition of full_extent_t and full_extent	2023-11 (Kona)			#105306
LWG3973	Monadic operations should be ADL-proof	2023-11 (Kona)			#105307
LWG3974	mdspan::operator[] should not copy OtherIndexTypes	2023-11 (Kona)			#105308
LWG3987	Including <flat_foo> doesn’t provide std::begin/end	2023-11 (Kona)	Complete		#105309
LWG3990	Program-defined specializations of std::tuple and std::variant can’t be properly supported	2023-11 (Kona)	Complete	21	#105310
LWG4001	iota_view should provide empty	2023-11 (Kona)	Complete	19	#105311
LWG3767	codecvt<charN_t, char8_t, mbstate_t> incorrectly added to locale	2024-03 (Tokyo)			#105313
LWG3919	enumerate_view may invoke UB for sized common non-forward underlying ranges	2024-03 (Tokyo)			#105315
LWG3950	std::basic_string_view comparison operators are overspecified	2024-03 (Tokyo)	Complete	18	#105316
LWG3975	Specializations of basic_format_context should not be permitted	2024-03 (Tokyo)	Nothing To Do		#105317
LWG3984	ranges::to’s recursion branch may be ill-formed	2024-03 (Tokyo)	Complete	19	#105318
LWG4011	“Effects: Equivalent to return” in [span.elem]	2024-03 (Tokyo)	Nothing To Do		#105319
LWG4012	common_view::begin/end are missing the simple-view check	2024-03 (Tokyo)			#105320
LWG4013	lazy_split_view::outer-iterator::value_type should not provide default constructor	2024-03 (Tokyo)			#105321
LWG4016	container-insertable checks do not match what container-inserter does	2024-03 (Tokyo)	Complete	20	#105322
LWG4023	Preconditions of std::basic_streambuf::setg/setp	2024-03 (Tokyo)	Complete	19	#105323
LWG4025	Move assignment operator of std::expected<cv void, E> should not be conditionally deleted	2024-03 (Tokyo)	Complete	20	#105324
LWG4030	Clarify whether arithmetic expressions in [numeric.sat.func] are mathematical or C++	2024-03 (Tokyo)	Nothing To Do		#105325
LWG4031	bad_expected_access<void> member functions should be noexcept	2024-03 (Tokyo)	Complete	16	#105326
LWG4035	single_view should provide empty	2024-03 (Tokyo)	Complete	19	#105328
LWG4036	__alignof_is_defined is only implicitly specified in C++ and not yet deprecated	2024-03 (Tokyo)			#105329
LWG4037	Static data members of ctype_base are not yet required to be usable in constant expressions	2024-03 (Tokyo)			#105330
LWG4038	std::text_encoding::aliases_view should have constexpr iterators	2024-03 (Tokyo)			#105332
LWG4043	“ASCII” is not a registered character encoding	2024-03 (Tokyo)	Nothing To Do		#105335
LWG4045	tuple can create dangling references from tuple-like	2024-03 (Tokyo)			#105337
LWG4053	Unary call to std::views::repeat does not decay the argument	2024-03 (Tokyo)	Complete	19	#105338
LWG4054	Repeating a repeat_view should repeat the view	2024-03 (Tokyo)	Complete	19	#105340
LWG3944	Formatters converting sequences of char to sequences of wchar_t	2024-06 (St. Louis)	Complete	21	#105342
LWG4060	submdspan preconditions do not forbid creating invalid pointer	2024-06 (St. Louis)			#105343
LWG4061	Should std::basic_format_context be default-constructible/copyable/movable?	2024-06 (St. Louis)	Complete	19	#105344
LWG4071	reference_wrapper comparisons are not SFINAE-friendly	2024-06 (St. Louis)	Complete	19	#105345
LWG4074	compatible-joinable-ranges is underconstrained	2024-06 (St. Louis)	Complete	21	#105346
LWG4076	concat_view should be freestanding	2024-06 (St. Louis)			#105347
LWG4079	Missing Preconditions in concat_view::iterator`s conversion constructor	2024-06 (St. Louis)			#105348
LWG4082	views::concat(r) is well-formed when r is an output_range	2024-06 (St. Louis)			#105349
LWG4083	views::as_rvalue should reject non-input ranges	2024-06 (St. Louis)	Complete	22	#105351
LWG4096	views::iota(views::iota(0)) should be rejected	2024-06 (St. Louis)	Complete	22	#105352
LWG4098	views::adjacent<0> should reject non-forward ranges	2024-06 (St. Louis)			#105353
LWG4105	ranges::ends_with`s Returns misses difference casting	2024-06 (St. Louis)			#105354
LWG4106	basic_format_args should not be default-constructible	2024-06 (St. Louis)	Complete	19	#105355
LWG3216	Rebinding the allocator before calling construct/destroy in allocate_shared	2024-11 (Wrocław)			#118332
LWG3436	std::construct_at should support arrays	2024-11 (Wrocław)			#118335
LWG3886	Monad mo’ problems	2024-11 (Wrocław)	Complete	22	#118336
LWG3899	co_yielding elements of an lvalue generator is unnecessarily inefficient	2024-11 (Wrocław)			#118337
LWG3900	The allocator_arg_t overloads of generator::promise_type::operator new should not be constrained	2024-11 (Wrocław)			#118338
LWG3918	std::uninitialized_move/_n and guaranteed copy elision	2024-11 (Wrocław)			#118339
LWG4014	LWG 3809 changes behavior of some existing std::subtract_with_carry_engine code	2024-11 (Wrocław)			#118340
LWG4024	Underspecified destruction of objects created in std::make_shared_for_overwrite/std::allocate_shared_for_overwrite	2024-11 (Wrocław)	Complete	16	#118341
LWG4027	possibly-const-range should prefer returning const R&	2024-11 (Wrocław)			#118342
LWG4044	Confusing requirements for std::print on POSIX platforms	2024-11 (Wrocław)			#118343
LWG4064	Clarify that std::launder is not needed when using the result of std::memcpy	2024-11 (Wrocław)			#118344
LWG4072	std::optional comparisons: constrain harder	2024-11 (Wrocław)			#118345
LWG4084	std::fixed ignores std::uppercase	2024-11 (Wrocław)			#118346
LWG4085	ranges::generate_random’s helper lambda should specify the return type	2024-11 (Wrocław)			#118347
LWG4088	println ignores the locale imbued in std::ostream	2024-11 (Wrocław)	Complete	18	#118348
LWG4112	has-arrow should required operator->() to be const-qualified	2024-11 (Wrocław)			#118349
LWG4113	Disallow has_unique_object_representations<Incomplete[]>	2024-11 (Wrocław)	Complete		#118350
LWG4119	generator::promise_type::yield_value(ranges::elements_of<R, Alloc>)’s nested generator may be ill-formed	2024-11 (Wrocław)			#118351
LWG4124	Cannot format zoned_time with resolution coarser than seconds	2024-11 (Wrocław)			#118352
LWG4126	Some feature-test macros for fully freestanding features are not yet marked freestanding	2024-11 (Wrocław)			#118353
LWG4134	Issue with Philox algorithm specification	2024-11 (Wrocław)			#118354
LWG4135	The helper lambda of std::erase for list should specify return type as bool	2024-11 (Wrocław)	Complete	21	#118355
LWG4140	Useless default constructors for bit reference types	2024-11 (Wrocław)	Complete		#118356
LWG4141	Improve prohibitions on “additional storage”	2024-11 (Wrocław)			#118357
LWG4142	format_parse_context::check_dynamic_spec should require at least one type	2024-11 (Wrocław)			#118358
LWG4144	Disallow unique_ptr<T&, D>	2024-11 (Wrocław)			#118359
LWG4147	Precondition on inplace_vector::emplace	2024-11 (Wrocław)			#118361
LWG4148	unique_ptr::operator* should not allow dangling references	2024-11 (Wrocław)			#118362
LWG4153	Fix extra “-1” for philox_engine::max()	2024-11 (Wrocław)			#118363
LWG4154	The Mandates for std::packaged_task’s constructor from a callable entity should consider decaying	2024-11 (Wrocław)			#118364
LWG4157	The resolution of LWG3465 was damaged by P2167R3	2024-11 (Wrocław)	Complete	20	#118365
LWG4164	Missing guarantees for forward_list modifiers	2024-11 (Wrocław)	Complete	21	#118366
LWG4169	std::atomic<T>’s default constructor should be constrained	2024-11 (Wrocław)			#118367
LWG4170	contiguous_iterator should require to_address(I{})	2024-11 (Wrocław)			#118368
LWG3578	Iterator SCARYness in the context of associative container merging	2025-02 (Hagenberg)			#127859
LWG3956	chrono::parse uses from_stream as a customization point	2025-02 (Hagenberg)			#127860
LWG4172	unique_lock self-move-assignment is broken	2025-02 (Hagenberg)	Complete	22	#127861
LWG4175	get_env() specified in terms of as_const() but this doesn’t work with rvalue senders	2025-02 (Hagenberg)			#127862
LWG4179	Wrong range in [alg.search]	2025-02 (Hagenberg)			#127863
LWG4186	regex_traits::transform_primary mistakenly detects typeid of a function	2025-02 (Hagenberg)			#127864
LWG4189	cache_latest_view should be freestanding	2025-02 (Hagenberg)			#127865
LWG4191	P1467 changed the return type of pow(complex<float>, int)	2025-02 (Hagenberg)			#127866
LWG4196	Complexity of inplace_merge() is incorrect	2025-02 (Hagenberg)			#127867
LWG4198	schedule_from isn’t starting the schedule sender if decay-copying results throws	2025-06 (Sofia)			#148188
LWG4202	enable-sender should be a variable template	2025-06 (Sofia)			#148189
LWG4203	Constraints on get-state functions are incorrect	2025-06 (Sofia)			#148190
LWG4204	specification of as-sndr2(Sig) in [exec.let] is incomplete	2025-06 (Sofia)			#148192
LWG4205	let_[*].transform_env is specified in terms of the let_* sender itself instead of its child	2025-06 (Sofia)			#148193
LWG4208	Wording needs to ensure that in connect(sndr, rcvr) that rcvr expression is only evaluated once	2025-06 (Sofia)			#148194
LWG4209	default_domain::transform_env should be returning FWD-ENV(env)	2025-06 (Sofia)			#148196
LWG4188	ostream::sentry destructor should handle exceptions	2025-06 (Sofia)			#148200
LWG4200	The operation_state concept can be simplified	2025-06 (Sofia)			#148201
LWG4201	with-await-transform::await_transform should not use a deduced return type	2025-06 (Sofia)			#148202
LWG4217	Clarify mdspan layout mapping requirements for rank == 0	2025-06 (Sofia)			#148203
LWG4222	expected constructor from a single value missing a constraint	2025-06 (Sofia)	Complete	22	#148208
LWG4224	Philox engines should be freestanding	2025-06 (Sofia)			#148210
LWG4227	Missing noexcept operator in [exec.when.all]	2025-06 (Sofia)			#148211
LWG4231	datapar::chunk<N> should use simd-size-type instead of size_t	2025-06 (Sofia)			#148215
LWG4232	datapar::resize does not resize	2025-06 (Sofia)			#148216
LWG4233	The helper lambda of std::erase for hive should specify return type as bool	2025-06 (Sofia)			#148217
LWG4234	Including <hive> doesn’t provide std::begin/end	2025-06 (Sofia)			#148218
LWG4235	cache_latest_view and to_input_view miss reserve_hint	2025-06 (Sofia)			#148219
LWG4236	chunk_view::outer-iterator::value_type should provide reserve_hint	2025-06 (Sofia)			#148220
LWG4239	flat_map’s transparent comparator no longer works for string literals	2025-06 (Sofia)			#148223
LWG4242	ranges::distance does not work with volatile iterators	2025-06 (Sofia)			#148224
LWG4245	Operators that interact with counted_iterator and default_sentinel_t should be noexcept	2025-06 (Sofia)			#148226
LWG4247	Header <stdbit.h> is not yet freestanding	2025-06 (Sofia)			#148227
LWG2991	variant copy constructor missing noexcept(see below)	2025-11 (Kona)			#171301
LWG3090	What is §[time.duration.cons]p4’s “no overflow is induced in the conversion” intended to mean?	2025-11 (Kona)			#171302
LWG3343	Ordering of calls to unlock() and notify_all() in Effects element of notify_all_at_thread_exit() should be reversed	2025-11 (Kona)	Complete	16	#105356
LWG3454	pointer_traits::pointer_to should be constexpr	2025-11 (Kona)			#171307
LWG3627	Inconsistent specifications for std::make_optional overloads	2025-11 (Kona)			#171309
LWG4015	LWG 3973 broke const overloads of std::optional monadic operations	2025-11 (Kona)			#171310
LWG4020	extents::index-cast weirdness	2025-11 (Kona)			#171311
LWG4136	Specify behavior of [linalg] Hermitian algorithms on diagonal with nonzero imaginary part	2025-11 (Kona)			#171312
LWG4137	Fix Mandates, Preconditions, and Complexity elements of [linalg] algorithms	2025-11 (Kona)			#171313
LWG4166	concat_view::end() should be more constrained in order to support noncopyable iterators	2025-11 (Kona)			#171314
LWG4230	simd<complex>::real/imag is overconstrained	2025-11 (Kona)			#171316
LWG4243	as_bytes/as_writable_bytes is broken with span<volatile T>	2025-11 (Kona)			#171317
LWG4251	Move assignment for indirect unnecessarily requires copy construction	2025-11 (Kona)			#171318
LWG4253	basic_const_iterator should provide iterator_type	2025-11 (Kona)			#171319
LWG4255	move_only_function constructor should recognize empty copyable_functions	2025-11 (Kona)			#171320
LWG4256	Incorrect constrains for function_ref constructors from nontype_t	2025-11 (Kona)			#171321
LWG4257	Stream insertion for chrono::local_time should be constrained	2025-11 (Kona)			#171322
LWG4260	Query objects must be default constructible	2025-11 (Kona)			#171323
LWG4265	std::midpoint should not accept const bool	2025-11 (Kona)			#171324
LWG4266	layout_stride::mapping should treat empty mappings as exhaustive	2025-11 (Kona)			#171325
LWG4269	unique_copy passes arguments to its predicate backwards	2025-11 (Kona)			#171326
LWG4272	For rank == 0, layout_stride is atypically convertible	2025-11 (Kona)			#171327
LWG4274	The chrono::hh_mm_ss constructor is ill-formed for unsigned durations	2025-11 (Kona)			#171328
LWG4275	std::dynamic_extent should also be defined in <mdspan>	2025-11 (Kona)	Complete	21	#171329
LWG4276	front() and back() are not hardened for zero-length std::arrays	2025-11 (Kona)			#171330
LWG4280	simd::partial_load uses undefined identifier T	2025-11 (Kona)			#171331
LWG4286	Some more feature-test macros for fully freestanding features are not marked freestanding	2025-11 (Kona)			#171332
LWG4291	explicit map(const Allocator&) should be constexpr	2025-11 (Kona)			#171333
LWG4292	Unordered container local iterators should be constexpr iterators	2025-11 (Kona)			#171334
LWG4293	span::subspan/first/last chooses wrong constructor when T is const-qualified bool	2025-11 (Kona)			#171335
LWG4294	bitset(const CharT*) constructor needs to be constrained	2025-11 (Kona)			#171336
LWG4297	Missing permutable constraint for iterator overloads in Parallel Range Algorithms	2025-11 (Kona)			#171338
LWG4299	Missing Mandates: part in optional<T&>::transform	2025-11 (Kona)			#171339
LWG4300	Missing Returns: element in optional<T&>::emplace	2025-11 (Kona)			#171340
LWG4301	condition_variable{_any}::wait_{for, until} should take timeout by value	2025-11 (Kona)			#171341
LWG4302	Problematic vector_sum_of_squares wording	2025-11 (Kona)			#171342
LWG4304	std::optional<NonReturnable&> is ill-formed due to value_or	2025-11 (Kona)			#171343
LWG4305	Missing user requirements on type_order template	2025-11 (Kona)			#171344
LWG4308	std::optional<T&>::iterator can’t be a contiguous iterator for some T	2025-11 (Kona)			#171345
LWG4312	Const and value category mismatch for allocator_arg_t/allocator_arg in the description of uses-allocator construction	2025-11 (Kona)			#171346
LWG4315	Insufficient specification of vector_two_norm and matrix_frob_norm	2025-11 (Kona)			#171347
LWG4316	{can_}substitute specification is ill-formed	2025-11 (Kona)			#171348
LWG4317	The meaning of “resource” in the Cpp17Destructible requirements is undefined	2025-11 (Kona)			#171349
LWG4318	Have hive::erase_if reevaluate end() to avoid UB	2025-11 (Kona)			#171350
LWG4328	Remove note in §[exec.sched] regarding waiting for completion of scheduled operations	2025-11 (Kona)			#171351
LWG4340	task::promise_type::unhandled_stopped() should be noexcept	2025-11 (Kona)			#171352
LWG4341	Missing rvalue reference qualification for task::connect()	2025-11 (Kona)			#171353
LWG4342	Missing rvalue reference qualification for task_scheduler::ts-sender::connect()	2025-11 (Kona)			#171354
LWG4343	Missing default template arguments for task	2025-11 (Kona)			#171355
LWG4345	task::promise_type::return_value default template parameter	2025-11 (Kona)			#171356
LWG4346	task::promise_type::return_void/value lack a specification	2025-11 (Kona)			#171357
LWG4349	task is not actually started lazily	2025-11 (Kona)			#171358
LWG4351	integral-constant-like needs more remove_cvref_t	2025-11 (Kona)			#171359
LWG4358	§[exec.as.awaitable] is using “Preconditions:” when it should probably be described in the constraint	2025-11 (Kona)			#171360
LWG4360	awaitable-sender concept should qualify use of awaitable-receiver type	2025-11 (Kona)			#171361
LWG4366	Heterogeneous comparison of expected may be ill-formed	2025-11 (Kona)			#171362
LWG4369	check-types function for upon_error and upon_stopped is wrong	2025-11 (Kona)			#171363
LWG4370	Comparison of optional<T> to T may be ill-formed	2025-11 (Kona)			#171364
LWG4372	Weaken Mandates: for dynamic padding values in padded layouts	2025-11 (Kona)			#171365
LWG4375	std::simd::bit_ceil should not be noexcept	2025-11 (Kona)			#171366
LWG4376	ABI tag in return type of [simd.mask.unary] is overconstrained	2025-11 (Kona)			#171367
LWG4377	Misleading note about lock-free property of std::atomic_ref	2025-11 (Kona)			#171368
LWG4382	The simd::basic_mask(bool) overload needs to be more constrained	2025-11 (Kona)			#171369
LWG4383	constant_wrapper's pseudo-mutators are underconstrained	2025-11 (Kona)			#171370
LWG4384	flat_set::erase(iterator) is underconstrained	2025-11 (Kona)			#171371
LWG4388	Align new definition of va_start with C23	2025-11 (Kona)			#171372
LWG4396	Improve inplace_vector(from_range_t, R&& rg)	2025-11 (Kona)			#171373
LWG4398	enable_nonlocking_formatter_optimization should be disabled for container adaptors	2025-11 (Kona)			#171375
LWG4399	enable_nonlocking_formatter_optimization for pair and tuple needs remove_cvref_t	2025-11 (Kona)			#171376
LWG4403	simd::basic_vec CTAD misses difference type casting	2025-11 (Kona)			#171377
LWG4407	constexpr-wrapper-like needs remove_cvref_t in simd::basic_vec constructor	2025-11 (Kona)			#171378
LWG4412	Fix declaration of zero_element and uninit_element	2025-11 (Kona)			#171379
LWG4413	Unused/left-over simd::alignment specialization for basic_mask	2025-11 (Kona)			#171380
LWG4415	task::promise_type::uncaught_exception seems to be misnamed	2025-11 (Kona)			#171381
LWG4416	<meta> should include <compare>	2025-11 (Kona)			#171382
LWG4420	§[simd] conversions (constructor, load, stores, gather, and scatter) are incorrectly constrained for <stdfloat> types	2025-11 (Kona)			#171383
LWG4422	meta::access_context should be a consteval-only type	2025-11 (Kona)			#171384
LWG4423	meta::data_member_spec allows negative bit-field widths	2025-11 (Kona)			#171385
LWG4424	meta::define_aggregate should require a class type	2025-11 (Kona)			#171386
LWG4425	CTAD function_ref of data member pointer should produce noexcept signature	2025-11 (Kona)			#171387
LWG4426	Clarify what meta::reflect_constant_string considers a string literal	2025-11 (Kona)			#171388
LWG4427	meta::dealias needs to work with things that aren’t entities	2025-11 (Kona)			#171390
LWG4428	Metafunctions should not be defined in terms of constant subexpressions	2025-11 (Kona)			#171391
LWG4429	meta::alignment_of should exclude data member description of bit-field	2025-11 (Kona)			#171393
LWG4430	from_chars should not parse 0b" base prefixes”	2025-11 (Kona)			#171394
LWG4431	Parallel std::ranges::destroy should allow exceptions	2025-11 (Kona)			#171396
LWG4432	Clarify element initialization for meta::reflect_constant_array	2025-11 (Kona)			#171397
LWG4433	Incorrect query for C language linkage	2025-11 (Kona)			#171398
LWG4434	meta::is_accessible does not need to consider incomplete D	2025-11 (Kona)			#171399
LWG4435	meta::has_identifier doesn’t handle all types	2025-11 (Kona)			#171400
LWG4438	Bad expression in [exec.when.all]	2025-11 (Kona)			#171401
LWG4439	std::optional<T&>::swap possibly selects ADL-found swap	2025-11 (Kona)			#171402
LWG4440	Forward declarations of entities need also in entries	2025-11 (Kona)			#171403
LWG4441	ranges::rotate do not handle sized-but-not-sized-sentinel ranges correctly	2025-11 (Kona)			#171404
LWG4442	Clarify expr and fn for meta::reflect_object and meta::reflect_function	2025-11 (Kona)			#171405
LWG4443	Clean up identifier comparisons in meta::define_aggregate	2025-11 (Kona)			#171406
LWG4444	Fix default template arguments for ranges::replace and ranges::replace_if	2025-11 (Kona)			#171407
LWG4445	sch_ must not be in moved-from state	2025-11 (Kona)			#171408
LWG4446	Bad phrasing for SCHED(s)	2025-11 (Kona)			#171409
LWG4447	Remove unnecessary sizeof...(Env) > 1 condition	2025-11 (Kona)			#171410
LWG4448	Do not forward fn in completion_signatures	2025-11 (Kona)			#171411
LWG4449	define_aggregate members must be public	2025-11 (Kona)			#171412
LWG4450	std::atomic_ref<T>::store_key should be disabled for const T	2025-11 (Kona)			#171414
LWG4451	make_shared should not refer to a type U[N] for runtime N	2025-11 (Kona)			#171415
LWG4452	Make deref-move constexpr	2025-11 (Kona)			#171416
LWG4455	Add missing constraint to basic-sender::get_completion_signatures definition	2025-11 (Kona)			#171417
LWG4456	Decay Data and Child in make-sender	2025-11 (Kona)			#171418
LWG4459	Protect get_completion_signatures fold expression from overloaded commas	2025-11 (Kona)			#171419
LWG4461	stop-when needs to evaluate unstoppable tokens	2025-11 (Kona)			#171420
LWG4462	Algorithm requirements don’t describe semantics of s - i well	2025-11 (Kona)			#171421
LWG4463	Change wording to ‘model’ from ‘subsumes’ in [algorithms.parallel.user]	2025-11 (Kona)			#171422
LWG4464	§[alg.merge] Wording tweaks	2025-11 (Kona)			#171423
LWG4465	§[alg.partitions] Clarify Returns: element	2025-11 (Kona)			#171424
LWG4139	§[time.zone.leap] recursive constraint in <=>	Not Adopted Yet	Complete	20	#118369
LWG3456	Pattern used by std::from_chars is underspecified (option B)	Not Adopted Yet	Complete	20	#118370
LWG3882	tuple relational operators have confused friendships	Not Adopted Yet	Complete	22		The comparison operators are constrained harder than the proposed resolution. libstdc++ and MSVC STL do the same.