libc++ C++23 Status

Overview

In November 2020, the C++ standard committee adopted the first changes to the next version of the C++ standard, known here as “C++2b” (probably to be C++23). In February 2023, the C++ standard committee approved this draft, and sent it to ISO for approval as C++23.

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

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	Notes
P0881R7	A Proposal to add stacktrace library	2020-11 (Virtual)
P0943R6	Support C atomics in C++	2020-11 (Virtual)	Complete	15
P1048R1	A proposal for a type trait to detect scoped enumerations	2020-11 (Virtual)	Complete	12
P1679R3	string contains function	2020-11 (Virtual)	Complete	12
P1682R3	std::to_underlying for enumerations	2021-02 (Virtual)	Complete	13
P2017R1	Conditionally borrowed ranges	2021-02 (Virtual)	Complete	16
P2160R1	Locks lock lockables	2021-02 (Virtual)	Nothing To Do
P2162R2	Inheriting from std::variant	2021-02 (Virtual)	Complete	13
P2212R2	Relax Requirements for time_point::clock	2021-02 (Virtual)	Nothing To Do
P2259R1	Repairing input range adaptors and counted_iterator	2021-02 (Virtual)
P0401R6	Providing size feedback in the Allocator interface	2021-06 (Virtual)	Complete	15
P0448R4	A strstream replacement using span<charT> as buffer	2021-06 (Virtual)
P1132R8	out_ptr - a scalable output pointer abstraction	2021-06 (Virtual)	Complete	19
P1328R1	Making std::type_info::operator== constexpr	2021-06 (Virtual)	Complete	17
P1425R4	Iterators pair constructors for stack and queue	2021-06 (Virtual)	Complete	14
P1518R2	Stop overconstraining allocators in container deduction guides	2021-06 (Virtual)	Complete	13
P1659R3	starts_with and ends_with	2021-06 (Virtual)	Complete	19
P1951R1	Default Arguments for pair Forwarding Constructor	2021-06 (Virtual)	Complete	14
P1989R2	Range constructor for std::string_view	2021-06 (Virtual)	Complete	14
P2136R3	invoke_r	2021-06 (Virtual)	Complete	17
P2166R1	A Proposal to Prohibit std::basic_string and std::basic_string_view construction from nullptr	2021-06 (Virtual)	Complete	13
P0288R9	any_invocable	2021-10 (Virtual)
P0798R8	Monadic operations for std::optional	2021-10 (Virtual)	Complete	14
P0849R8	auto(x): DECAY_COPY in the language	2021-10 (Virtual)	Complete	14
P1072R10	basic_string::resize_and_overwrite	2021-10 (Virtual)	Complete	14
P1147R1	Printing volatile Pointers	2021-10 (Virtual)	Complete	14
P1272R4	Byteswapping for fun&&nuf	2021-10 (Virtual)	Complete	14
P1675R2	rethrow_exception must be allowed to copy	2021-10 (Virtual)	Nothing To Do
P2077R3	Heterogeneous erasure overloads for associative containers	2021-10 (Virtual)
P2251R1	Require span & basic_string_view to be Trivially Copyable	2021-10 (Virtual)	Complete	14
P2301R1	Add a pmr alias for std::stacktrace	2021-10 (Virtual)
P2321R2	zip	2021-10 (Virtual)	In Progress
P2340R1	Clarifying the status of the ‘C headers’	2021-10 (Virtual)	Nothing To Do
P2393R1	Cleaning up integer-class types	2021-10 (Virtual)
P2401R0	Add a conditional noexcept specification to std::exchange	2021-10 (Virtual)	Complete	14
P0323R12	std::expected	2022-02 (Virtual)	Complete	16
P0533R9	constexpr for <cmath> and <cstdlib>	2022-02 (Virtual)	In Progress		isfinite, isinf, isnan and isnormal are implemented
P0627R6	Function to mark unreachable code	2022-02 (Virtual)	Complete	15
P1206R7	ranges::to: A function to convert any range to a container	2022-02 (Virtual)	Complete	17
P1413R3	Deprecate std::aligned_storage and std::aligned_union	2022-02 (Virtual)	Complete		std::aligned_storage_t and std::aligned_union_t are marked deprecated, but clang doesn’t issue a diagnostic for deprecated using template declarations.
P2255R2	A type trait to detect reference binding to temporary	2022-02 (Virtual)
P2273R3	Making std::unique_ptr constexpr	2022-02 (Virtual)	Complete	16
P2387R3	Pipe support for user-defined range adaptors	2022-02 (Virtual)	Complete	19
P2440R1	ranges::iota, ranges::shift_left and ranges::shift_right	2022-02 (Virtual)
P2441R2	views::join_with	2022-02 (Virtual)	In Progress
P2442R1	Windowing range adaptors: views::chunk and views::slide	2022-02 (Virtual)
P2443R1	views::chunk_by	2022-02 (Virtual)	Complete	18
P0009R18	mdspan: A Non-Owning Multidimensional Array Reference	2022-07 (Virtual)	Complete	18
P0429R9	A Standard flat_map	2022-07 (Virtual)	In Progress
P1169R4	static operator()	2022-07 (Virtual)	Complete	16
P1222R4	A Standard flat_set	2022-07 (Virtual)
P1223R5	ranges::find_last(), ranges::find_last_if(), and ranges::find_last_if_not()	2022-07 (Virtual)	Complete	19
P1467R9	Extended floating-point types and standard names	2022-07 (Virtual)
P1642R11	Freestanding [utilities], [ranges], and [iterators]	2022-07 (Virtual)
P1899R3	stride_view	2022-07 (Virtual)
P2093R14	Formatted output	2022-07 (Virtual)	Complete	18
P2165R4	Compatibility between tuple, pair and tuple-like objects	2022-07 (Virtual)	Partial		Only the part for zip_view is implemented.
P2278R4	cbegin should always return a constant iterator	2022-07 (Virtual)
P2286R8	Formatting Ranges	2022-07 (Virtual)	Complete	16
P2291R3	Add Constexpr Modifiers to Functions to_chars and from_chars for Integral Types in <charconv> Header	2022-07 (Virtual)	Complete	16
P2302R4	std::ranges::contains	2022-07 (Virtual)	Complete	19
P2322R6	ranges::fold	2022-07 (Virtual)
P2374R4	views::cartesian_product	2022-07 (Virtual)
P2404R3	Move-only types for equality_comparable_with, totally_ordered_with, and three_way_comparable_with	2022-07 (Virtual)
P2408R5	Ranges iterators as inputs to non-Ranges algorithms	2022-07 (Virtual)
P2417R2	A more constexpr bitset	2022-07 (Virtual)	Complete	16
P2419R2	Clarify handling of encodings in localized formatting of chrono types	2022-07 (Virtual)
P2438R2	std::string::substr() &&	2022-07 (Virtual)	Complete	16
P2445R1	forward_like	2022-07 (Virtual)	Complete	16
P2446R2	views::as_rvalue	2022-07 (Virtual)	Complete	16
P2460R2	Relax requirements on wchar_t to match existing practices	2022-07 (Virtual)	Nothing To Do
P2465R3	Standard Library Modules std and std.compat	2022-07 (Virtual)	Complete	19
P2467R1	Support exclusive mode for fstreams	2022-07 (Virtual)	Complete	18
P2474R2	views::repeat	2022-07 (Virtual)	Complete	17
P2494R2	Relaxing range adaptors to allow for move only types	2022-07 (Virtual)	Complete	17
P2499R0	string_view range constructor should be explicit	2022-07 (Virtual)	Complete	16
P2502R2	std::generator: Synchronous Coroutine Generator for Ranges	2022-07 (Virtual)
P2508R1	Exposing std::basic-format-string	2022-07 (Virtual)	Complete	15
P2513R4	char8_t Compatibility and Portability Fixes	2022-07 (Virtual)
P2517R1	Add a conditional noexcept specification to std::apply	2022-07 (Virtual)	Complete	3.9
P2520R0	move_iterator should be a random access iterator	2022-07 (Virtual)	Complete	17	Implemented as a DR in C++20
P2540R1	Empty Product for certain Views	2022-07 (Virtual)
P2549R1	std::unexpected should have error() as member accessor	2022-07 (Virtual)	Complete	16
P2585R0	Improving default container formatting	2022-07 (Virtual)	Complete	17
P2590R2	Explicit lifetime management	2022-07 (Virtual)
P2599R2	mdspan::size_type should be index_type	2022-07 (Virtual)	Complete	18
P2604R0	mdspan: rename pointer and contiguous	2022-07 (Virtual)	Complete	18
P2613R1	Add the missing empty to mdspan	2022-07 (Virtual)	Complete	18
P1202R5	Asymmetric Fences	2022-11 (Kona)
P1264R2	Revising the wording of stream input operations	2022-11 (Kona)	Complete	9
P1478R8	Byte-wise atomic memcpy	2022-11 (Kona)
P2167R3	Improved Proposed Wording for LWG 2114	2022-11 (Kona)	Complete	20	The [cmp.alg] part is implemented as a DR against C++20. MSVC STL does the same. Other parts are Nothing To Do.
P2396R1	Concurrency TS 2 fixes	2022-11 (Kona)
P2505R5	Monadic Functions for std::expected	2022-11 (Kona)	Complete	17
P2539R4	Should the output of std::print to a terminal be synchronized with the underlying stream?	2022-11 (Kona)	Complete	18
P2602R2	Poison Pills are Too Toxic	2022-11 (Kona)	Complete	19	Implemented as a DR in C++20
P2708R1	No Further Fundamentals TSes	2022-11 (Kona)	Nothing To Do
P0290R4	apply() for synchronized_value<T>	2023-02 (Issaquah)
P2770R0	Stashing stashing iterators for proper flattening	2023-02 (Issaquah)	Partial		join_with_view hasn’t been done yet since this type isn’t implemented yet
P2164R9	views::enumerate	2023-02 (Issaquah)
P2711R1	Making multi-param constructors of views explicit	2023-02 (Issaquah)	In Progress		join_with_view hasn’t been done yet since this type isn’t implemented yet
P2609R3	Relaxing Ranges Just A Smidge	2023-02 (Issaquah)	Complete	20	Implemented as a DR in C++20. Other implementations will do the same.
P2713R1	Escaping improvements in std::format	2023-02 (Issaquah)	Complete	19
P2675R1	format’s width estimation is too approximate and not forward compatible	2023-02 (Issaquah)	Complete	17
P2572R1	std::format fill character allowances	2023-02 (Issaquah)	Complete	17
P2693R1	Formatting thread::id and stacktrace	2023-02 (Issaquah)	Partial		The formatter for stacktrace is not implemented, since stacktrace is not implemented yet
P2679R2	Fixing std::start_lifetime_as for arrays	2023-02 (Issaquah)
P2674R1	A trait for implicit lifetime types	2023-02 (Issaquah)	Complete	20
P2655R3	common_reference_t of reference_wrapper Should Be a Reference Type	2023-02 (Issaquah)
P2652R2	Disallow User Specialization of allocator_traits	2023-02 (Issaquah)	Complete	19
P2787R1	pmr::generator - Promise Types are not Values	2023-02 (Issaquah)
P2614R2	Deprecate numeric_limits::has_denorm	2023-02 (Issaquah)	Complete	18
P2588R3	barrier’s phase completion guarantees	2023-02 (Issaquah)
P2763R1	layout_stride static extents default constructor fix	2023-02 (Issaquah)
P2736R2	Referencing The Unicode Standard	2023-02 (Issaquah)	Complete	19

Library Working Group Issues Status

Issue #	Issue Name	Meeting	Status	First released version	Notes
LWG2839	Self-move-assignment of library types, again	2020-11 (Virtual)	Nothing To Do
LWG3117	Missing packaged_task deduction guides	2020-11 (Virtual)	Complete	16
LWG3143	monotonic_buffer_resource growth policy is unclear	2020-11 (Virtual)
LWG3195	What is the stored pointer value of an empty weak_ptr?	2020-11 (Virtual)	Nothing To Do
LWG3211	std::tuple<> should be trivially constructible	2020-11 (Virtual)	Complete	9
LWG3236	Random access iterator requirements lack limiting relational operators domain to comparing those from the same range	2020-11 (Virtual)	Nothing To Do
LWG3265	move_iterator’s conversions are more broken after P1207	2020-11 (Virtual)	Nothing To Do		Resolved by LWG3435
LWG3435	three_way_comparable_with<reverse_iterator<int*>, reverse_iterator<const int*>>	2020-11 (Virtual)	Complete	13
LWG3432	Missing requirement for comparison_category	2020-11 (Virtual)	Complete	16
LWG3447	Deduction guides for take_view and drop_view have different constraints	2020-11 (Virtual)	Complete	14
LWG3450	The const overloads of take_while_view::begin/end are underconstrained	2020-11 (Virtual)	Complete	16
LWG3464	istream::gcount() can overflow	2020-11 (Virtual)	Complete	18
LWG2731	Existence of lock_guard<MutexTypes...>::mutex_type typedef unclear	2020-11 (Virtual)	Complete	5
LWG2743	P0083R3 node_handle private members missing “exposition only” comment	2020-11 (Virtual)	Nothing To Do
LWG2820	Clarify <cstdint> macros	2020-11 (Virtual)	Nothing To Do
LWG3120	Unclear behavior of monotonic_buffer_resource::release()	2020-11 (Virtual)
LWG3170	is_always_equal added to std::allocator makes the standard library treat derived types as always equal	2020-11 (Virtual)	Complete	18
LWG3036	polymorphic_allocator::destroy is extraneous	2020-11 (Virtual)	Nothing To Do		Reverted by P2875R4
LWG3171	LWG2989 breaks directory_entry stream insertion	2020-11 (Virtual)	Complete	14
LWG3306	ranges::advance violates its preconditions	2020-11 (Virtual)	Complete	14
LWG3403	Domain of ranges::ssize(E) doesn’t match ranges::size(E)	2020-11 (Virtual)
LWG3404	Finish removing subrange’s conversions from pair-like	2020-11 (Virtual)	Complete	13
LWG3405	common_view’s converting constructor is bad, too	2020-11 (Virtual)	Complete	14
LWG3406	elements_view::begin() and elements_view::end() have incompatible constraints	2020-11 (Virtual)	Complete	16
LWG3419	[algorithms.requirements]/15 doesn’t reserve as many rights as it intends to	2020-11 (Virtual)	Nothing To Do
LWG3420	cpp17-iterator should check that the type looks like an iterator first	2020-11 (Virtual)	Complete	14
LWG3421	Imperfect ADL emulation for boolean-testable	2020-11 (Virtual)	Nothing To Do
LWG3425	condition_variable_any fails to constrain its Lock parameters	2020-11 (Virtual)	Nothing To Do
LWG3426	operator<=>(const unique_ptr<T, D>&, nullptr_t) can’t get no satisfaction	2020-11 (Virtual)	Complete	16
LWG3427	operator<=>(const shared_ptr<T>&, nullptr_t) definition ill-formed	2020-11 (Virtual)	Complete	16
LWG3428	single_view’s in place constructor should be explicit	2020-11 (Virtual)	Complete	14
LWG3434	ios_base never reclaims memory for iarray and parray	2020-11 (Virtual)	Nothing To Do
LWG3437	__cpp_lib_polymorphic_allocator is in the wrong header	2020-11 (Virtual)	Complete	14
LWG3446	indirectly_readable_traits ambiguity for types with both value_type and element_type	2020-11 (Virtual)	Complete	14
LWG3448	transform_view’s sentinel<false> not comparable with iterator<true>	2020-11 (Virtual)
LWG3449	take_view and take_while_view’s sentinel<false> not comparable with their const iterator	2020-11 (Virtual)	Complete	16
LWG3453	Generic code cannot call ranges::advance(i, s)	2020-11 (Virtual)	Nothing To Do
LWG3455	Incorrect Postconditions on unique_ptr move assignment	2020-11 (Virtual)	Nothing To Do
LWG3460	Unimplementable noop_coroutine_handle guarantees	2020-11 (Virtual)	Complete	14
LWG3461	convertible_to’s description mishandles cv-qualified void	2020-11 (Virtual)	Nothing To Do
LWG3465	compare_partial_order_fallback requires F < E	2020-11 (Virtual)	Complete	14
LWG3466	Specify the requirements for promise/future/shared_future consistently	2020-11 (Virtual)	Nothing To Do
LWG3467	bool can’t be an integer-like type	2020-11 (Virtual)	Complete	14
LWG3472	counted_iterator is missing preconditions	2020-11 (Virtual)	Complete	14
LWG3473	Normative encouragement in non-normative note	2020-11 (Virtual)	Complete	15
LWG3474	Nesting join_views is broken because of CTAD	2020-11 (Virtual)	Complete	15
LWG3476	thread and jthread constructors require that the parameters be move-constructible but never move construct the parameters	2020-11 (Virtual)
LWG3477	Simplify constraints for semiregular-box	2020-11 (Virtual)	Complete	13
LWG3482	drop_view’s const begin should additionally require sized_range	2020-11 (Virtual)	Complete	14
LWG3483	transform_view::iterator’s difference is overconstrained	2020-11 (Virtual)	Complete	14
LWG3391	Problems with counted_iterator/move_iterator::base() const &	2021-02 (Virtual)
LWG3433	subrange::advance(n) has UB when n < 0	2021-02 (Virtual)	Complete	14
LWG3490	ranges::drop_while_view::begin() is missing a precondition	2021-02 (Virtual)	Nothing To Do
LWG3492	Minimal improvements to elements_view::iterator	2021-02 (Virtual)	Complete	16
LWG3494	Allow ranges to be conditionally borrowed	2021-02 (Virtual)	Nothing To Do		Superseded by P2017R1
LWG3495	constexpr launder makes pointers to inactive members of unions usable	2021-02 (Virtual)	Nothing To Do
LWG3500	join_view::iterator::operator->() is bogus	2021-02 (Virtual)	Complete	14
LWG3502	elements_view should not be allowed to return dangling reference	2021-02 (Virtual)	Complete	16
LWG3505	split_view::outer-iterator::operator++ misspecified	2021-02 (Virtual)
LWG2774	std::function construction vs assignment	2021-06 (Virtual)
LWG2818	::std:: everywhere rule needs tweaking	2021-06 (Virtual)	Nothing To Do
LWG2997	LWG 491 and the specification of {forward_,}list::unique	2021-06 (Virtual)
LWG3410	lexicographical_compare_three_way is overspecified	2021-06 (Virtual)	Complete	17
LWG3430	std::fstream & co. should be constructible from string_view	2021-06 (Virtual)	Complete	19
LWG3462	§[formatter.requirements]: Formatter requirements forbid use of fc.arg()	2021-06 (Virtual)	Nothing To Do
LWG3481	viewable_range mishandles lvalue move-only views	2021-06 (Virtual)	Nothing To Do		Superseded by P2415R2
LWG3506	Missing allocator-extended constructors for priority_queue	2021-06 (Virtual)	Complete	14
LWG3517	join_view::iterator’s iter_swap is underconstrained	2021-06 (Virtual)	Complete	14
LWG3518	Exception requirements on char trait operations unclear	2021-06 (Virtual)	Nothing To Do
LWG3519	Incomplete synopses for <random> classes	2021-06 (Virtual)
LWG3520	iter_move and iter_swap are inconsistent for transform_view::iterator	2021-06 (Virtual)	Complete	14
LWG3521	Overly strict requirements on qsort and bsearch	2021-06 (Virtual)	Nothing To Do
LWG3522	Missing requirement on InputIterator template parameter for priority_queue constructors	2021-06 (Virtual)	Complete	14
LWG3523	iota_view::sentinel is not always iota_view’s sentinel	2021-06 (Virtual)	Complete	17
LWG3526	Return types of uses_allocator_construction_args unspecified	2021-06 (Virtual)
LWG3527	uses_allocator_construction_args handles rvalue pairs of rvalue references incorrectly	2021-06 (Virtual)
LWG3528	make_from_tuple can perform (the equivalent of) a C-style cast	2021-06 (Virtual)	Complete	19
LWG3529	priority_queue(first, last) should construct c with (first, last)	2021-06 (Virtual)	Complete	14
LWG3530	BUILTIN-PTR-MEOW should not opt the type out of syntactic checks	2021-06 (Virtual)
LWG3532	split_view<V, P>::inner-iterator<true>::operator++(int) should depend on Base	2021-06 (Virtual)
LWG3533	Make base() const & consistent across iterator wrappers that supports input_iterators	2021-06 (Virtual)	Complete	14
LWG3536	Should chrono::from_stream() assign zero to duration for failure?	2021-06 (Virtual)
LWG3539	format_to must not copy models of output_iterator<const charT&>	2021-06 (Virtual)	Complete	14
LWG3540	§[format.arg] There should be no const in basic_format_arg(const T* p)	2021-06 (Virtual)	Complete	14
LWG3541	indirectly_readable_traits should be SFINAE-friendly for all types	2021-06 (Virtual)	Complete	14
LWG3542	basic_format_arg mishandles basic_string_view with custom traits	2021-06 (Virtual)	Complete	14
LWG3543	Definition of when counted_iterators refer to the same sequence isn’t quite right	2021-06 (Virtual)	Nothing To Do
LWG3544	format-arg-store::args is unintentionally not exposition-only	2021-06 (Virtual)	Complete	14
LWG3546	common_iterator’s postfix-proxy is not quite right	2021-06 (Virtual)
LWG3548	shared_ptr construction from unique_ptr should move (not copy) the deleter	2021-06 (Virtual)	Complete	15
LWG3549	view_interface is overspecified to derive from view_base	2021-06 (Virtual)	Complete	14
LWG3551	borrowed_{iterator,subrange}_t are overspecified	2021-06 (Virtual)	Nothing To Do
LWG3552	Parallel specialized memory algorithms should require forward iterators	2021-06 (Virtual)
LWG3553	Useless constraint in split_view::outer-iterator::value_type::begin()	2021-06 (Virtual)
LWG3555	{transform,elements}_view::iterator::iterator_concept should consider const-qualification of the underlying range	2021-06 (Virtual)
LWG2191	Incorrect specification of match_results(match_results&&)	2021-10 (Virtual)	Nothing To Do
LWG2381	Inconsistency in parsing floating point numbers	2021-10 (Virtual)	Complete	19
LWG2762	unique_ptr operator*() should be noexcept	2021-10 (Virtual)	Complete	19
LWG3121	tuple constructor constraints for UTypes&&... overloads	2021-10 (Virtual)
LWG3123	duration constructor from representation shouldn’t be effectively non-throwing	2021-10 (Virtual)
LWG3146	Excessive unwrapping in std::ref/cref	2021-10 (Virtual)	Complete	14
LWG3152	common_type and common_reference have flaws in common	2021-10 (Virtual)
LWG3293	move_iterator operator+() has incorrect constraints	2021-10 (Virtual)	Complete	15
LWG3361	safe_range<SomeRange&> case	2021-10 (Virtual)	Nothing To Do
LWG3392	ranges::distance() cannot be used on a move-only iterator with a sized sentinel	2021-10 (Virtual)	Complete	14
LWG3407	Some problems with the wording changes of P1739R4	2021-10 (Virtual)	Complete	15
LWG3422	Issues of seed_seq’s constructors	2021-10 (Virtual)	Complete	14
LWG3470	convertible-to-non-slicing seems to reject valid case	2021-10 (Virtual)	Complete	14
LWG3480	directory_iterator and recursive_directory_iterator are not C++20 ranges	2021-10 (Virtual)	Complete	14
LWG3498	Inconsistent noexcept-specifiers for basic_syncbuf	2021-10 (Virtual)
LWG3535	join_view::iterator::iterator_category and ::iterator_concept lie	2021-10 (Virtual)	Complete	15
LWG3554	chrono::parse needs const charT* and basic_string_view<charT> overloads	2021-10 (Virtual)
LWG3557	The static_cast expression in convertible_to has the wrong operand	2021-10 (Virtual)	Complete	14
LWG3559	Semantic requirements of sized_range is circular	2021-10 (Virtual)	Nothing To Do
LWG3560	ranges::equal and ranges::is_permutation should short-circuit for sized_ranges	2021-10 (Virtual)
LWG3561	Issue with internal counter in discard_block_engine	2021-10 (Virtual)
LWG3563	keys_view example is broken	2021-10 (Virtual)
LWG3566	Constraint recursion for operator<=>(optional<T>, U)	2021-10 (Virtual)	Complete	17
LWG3567	Formatting move-only iterators take two	2021-10 (Virtual)	Complete	16
LWG3568	basic_istream_view needs to initialize value_	2021-10 (Virtual)	Complete	16
LWG3570	basic_osyncstream::emit should be an unformatted output function	2021-10 (Virtual)	Complete	18
LWG3571	flush_emit should set badbit if the emit call fails	2021-10 (Virtual)
LWG3572	copyable-box should be fully constexpr	2021-10 (Virtual)	Complete	14
LWG3573	Missing Throws element for basic_string_view(It begin, End end)	2021-10 (Virtual)	Complete	14
LWG3574	common_iterator should be completely constexpr-able	2021-10 (Virtual)	Complete	14
LWG3580	iota_view’s iterator’s binary operator+ should be improved	2021-10 (Virtual)	Complete	14
LWG3581	The range constructor makes basic_string_view not trivially move constructible	2021-10 (Virtual)	Complete	14
LWG3585	variant converting assignment with immovable alternative	2021-10 (Virtual)
LWG3589	The const lvalue reference overload of get for subrange does not constrain I to be copyable when N == 0	2021-10 (Virtual)	Complete	14
LWG3590	split_view::base() const & is overconstrained	2021-10 (Virtual)	Complete	16
LWG3591	lazy_split_view<input_view>::inner-iterator::base() && invalidates outer iterators	2021-10 (Virtual)
LWG3592	lazy_split_view needs to check the simpleness of Pattern	2021-10 (Virtual)
LWG3593	Several iterators’ base() const & and lazy_split_view::outer-iterator::value_type::end() missing noexcept	2021-10 (Virtual)
LWG3595	Exposition-only classes proxy and postfix-proxy for common_iterator should be fully constexpr	2021-10 (Virtual)	Complete	14
LWG3088	forward_list::merge behaviour unclear when passed *this	2022-02 (Virtual)
LWG3471	polymorphic_allocator::allocate does not satisfy Cpp17Allocator requirements	2022-02 (Virtual)
LWG3525	uses_allocator_construction_args fails to handle types convertible to pair	2022-02 (Virtual)
LWG3598	system_category().default_error_condition(0) is underspecified	2022-02 (Virtual)
LWG3601	common_iterator’s postfix-proxy needs indirectly_readable	2022-02 (Virtual)
LWG3607	contiguous_iterator should not be allowed to have custom iter_move and iter_swap behavior	2022-02 (Virtual)	Nothing To Do
LWG3610	iota_view::size sometimes rejects integer-class types	2022-02 (Virtual)
LWG3612	Inconsistent pointer alignment in std::format	2022-02 (Virtual)	Complete	14
LWG3616	LWG 3498 seems to miss the non-member swap for basic_syncbuf	2022-02 (Virtual)	Complete	18
LWG3618	Unnecessary iter_move for transform_view::iterator	2022-02 (Virtual)	Complete	19
LWG3619	Specification of vformat_to contains ill-formed formatted_size calls	2022-02 (Virtual)	Nothing To Do
LWG3621	Remove feature-test macro __cpp_lib_monadic_optional	2022-02 (Virtual)	Complete	15
LWG3632	unique_ptr “Mandates: This constructor is not selected by class template argument deduction”	2022-02 (Virtual)	Nothing To Do
LWG3643	Missing constexpr in std::counted_iterator	2022-02 (Virtual)	Complete	19
LWG3648	format should not print bool with 'c'	2022-02 (Virtual)	Complete	15
LWG3649	[fund.ts.v2] Reinstate and bump __cpp_lib_experimental_memory_resource feature test macro	2022-02 (Virtual)
LWG3650	Are std::basic_string ‘s iterator and const_iterator constexpr iterators?	2022-02 (Virtual)	Nothing To Do
LWG3654	basic_format_context::arg(size_t) should be noexcept	2022-02 (Virtual)	Complete	15
LWG3657	std::hash<std::filesystem::path> is not enabled	2022-02 (Virtual)	Complete	17
LWG3660	iterator_traits<common_iterator>::pointer should conform to §[iterator.traits]	2022-02 (Virtual)	Complete	14
LWG3661	constinit atomic<shared_ptr<T>> a(nullptr); should work	2022-02 (Virtual)
LWG3564	transform_view::iterator<true>::value_type and iterator_category should use const F&	2022-07 (Virtual)	Complete	20
LWG3617	function/packaged_task deduction guides and deducing this	2022-07 (Virtual)
LWG3656	Inconsistent bit operations returning a count	2022-07 (Virtual)	Complete	15
LWG3659	Consider ATOMIC_FLAG_INIT undeprecation	2022-07 (Virtual)	Complete	15
LWG3670	Cpp17InputIterators don’t have integer-class difference types	2022-07 (Virtual)
LWG3671	atomic_fetch_xor missing from stdatomic.h	2022-07 (Virtual)	Complete	20
LWG3672	common_iterator::operator->() should return by value	2022-07 (Virtual)	Complete	19
LWG3683	operator== for polymorphic_allocator cannot deduce template argument in common cases	2022-07 (Virtual)	Complete	20
LWG3687	expected<cv void, E> move constructor should move	2022-07 (Virtual)	Complete	16
LWG3692	zip_view::iterator’s operator<=> is overconstrained	2022-07 (Virtual)	Complete	20
LWG3701	Make formatter<remove_cvref_t<const charT[N]>, charT> requirement explicit	2022-07 (Virtual)	Complete	15
LWG3702	Should zip_transform_view::iterator remove operator<	2022-07 (Virtual)
LWG3703	Missing requirements for expected<T, E> requires is_void<T>	2022-07 (Virtual)	Complete	16
LWG3704	LWG 2059 added overloads that might be ill-formed for sets	2022-07 (Virtual)
LWG3705	Hashability shouldn’t depend on basic_string’s allocator	2022-07 (Virtual)	Complete	16
LWG3707	chunk_view::outer-iterator::value_type::size should return unsigned type	2022-07 (Virtual)
LWG3708	take_while_view::sentinel’s conversion constructor should move	2022-07 (Virtual)	Complete	16
LWG3709	LWG-3703 was underly ambitious	2022-07 (Virtual)
LWG3710	The end of chunk_view for input ranges can be const	2022-07 (Virtual)
LWG3711	Missing preconditions for slide_view constructor	2022-07 (Virtual)
LWG3712	chunk_view and slide_view should not be default_initializable	2022-07 (Virtual)
LWG3713	Sorted with respect to comparator (only)	2022-07 (Virtual)	Nothing To Do
LWG3715	view_interface::empty is overconstrained	2022-07 (Virtual)	Complete	19
LWG3719	Directory iterators should be usable with default sentinel	2022-07 (Virtual)	Complete	17
LWG3721	Allow an arg-id with a value of zero for width in std-format-spec	2022-07 (Virtual)	Complete	16
LWG3724	decay-copy should be constrained	2022-07 (Virtual)	Complete	14
LWG3028	Container requirements tables should distinguish const and non-const variables	2022-11 (Kona)
LWG3118	fpos equality comparison unspecified	2022-11 (Kona)
LWG3177	Limit permission to specialize variable templates to program-defined types	2022-11 (Kona)	Nothing To Do
LWG3515	§[stacktrace.basic.nonmem]: operator<< should be less templatized	2022-11 (Kona)
LWG3545	std::pointer_traits should be SFINAE-friendly	2022-11 (Kona)	Complete	18
LWG3569	join_view fails to support ranges of ranges with non-default_initializable iterators	2022-11 (Kona)
LWG3594	inout_ptr — inconsistent release() in destructor	2022-11 (Kona)	Complete	19
LWG3597	Unsigned integer types don’t model advanceable	2022-11 (Kona)
LWG3600	Making istream_iterator copy constructor trivial is an ABI break	2022-11 (Kona)
LWG3629	make_error_code and make_error_condition are customization points	2022-11 (Kona)	Complete	16
LWG3636	formatter<T>::format should be const-qualified	2022-11 (Kona)	Complete	16
LWG3646	std::ranges::view_interface::size returns a signed type	2022-11 (Kona)	Complete	16
LWG3677	Is a cv-qualified pair specially handled in uses-allocator construction?	2022-11 (Kona)	Complete	18
LWG3717	common_view::end should improve random_access_range case	2022-11 (Kona)
LWG3732	prepend_range and append_range can’t be amortized constant time	2022-11 (Kona)	Nothing To Do
LWG3736	move_iterator missing disable_sized_sentinel_for specialization	2022-11 (Kona)	Complete	19
LWG3737	take_view::sentinel should provide operator-	2022-11 (Kona)
LWG3738	Missing preconditions for take_view constructor	2022-11 (Kona)	Complete	16
LWG3743	ranges::to’s reserve may be ill-formed	2022-11 (Kona)
LWG3745	std::atomic_wait and its friends lack noexcept	2022-11 (Kona)	Complete	16
LWG3746	optional’s spaceship with U with a type derived from optional causes infinite constraint meta-recursion	2022-11 (Kona)	Complete	17
LWG3747	ranges::uninitialized_copy_n, ranges::uninitialized_move_n, and ranges::destroy_n should use std::move	2022-11 (Kona)
LWG3750	Too many papers bump __cpp_lib_format	2022-11 (Kona)	Partial		Only __cpp_lib_format_ranges is fully implemented
LWG3751	Missing feature macro for flat_set	2022-11 (Kona)
LWG3753	Clarify entity vs. freestanding entity	2022-11 (Kona)
LWG3754	Class template expected synopsis contains declarations that do not match the detailed description	2022-11 (Kona)	Nothing To Do
LWG3755	tuple-for-each can call user-defined operator,	2022-11 (Kona)	Complete	17
LWG3757	What’s the effect of std::forward_like<void>(x)?	2022-11 (Kona)
LWG3759	ranges::rotate_copy should use std::move	2022-11 (Kona)	Complete	15
LWG3760	cartesian_product_view::iterator’s parent_ is never valid	2022-11 (Kona)
LWG3761	cartesian_product_view::iterator::operator- should pass by reference	2022-11 (Kona)
LWG3762	generator::iterator::operator== should pass by reference	2022-11 (Kona)
LWG3764	reference_wrapper::operator() should propagate noexcept	2022-11 (Kona)	Complete	17
LWG3765	const_sentinel should be constrained	2022-11 (Kona)
LWG3766	view_interface::cbegin is underconstrained	2022-11 (Kona)
LWG3770	const_sentinel_t is missing	2022-11 (Kona)
LWG3773	views::zip_transform still requires F to be copy_constructible when empty pack	2022-11 (Kona)
LWG3774	<flat_set> should include <compare>	2022-11 (Kona)
LWG3775	Broken dependencies in the Cpp17Allocator requirements	2022-11 (Kona)
LWG3778	vector<bool> missing exception specifications	2022-11 (Kona)	Complete	3.7
LWG3781	The exposition-only alias templates cont-key-type and cont-mapped-type should be removed	2022-11 (Kona)	Nothing To Do
LWG3782	Should <math.h> declare ::lerp?	2022-11 (Kona)	Complete	17
LWG3784	std.compat should not provide ::byte and its friends	2022-11 (Kona)	Complete	19
LWG3785	ranges::to is over-constrained on the destination type being a range	2022-11 (Kona)
LWG3788	jthread::operator=(jthread&&) postconditions are unimplementable under self-assignment	2022-11 (Kona)
LWG3792	__cpp_lib_constexpr_algorithms should also be defined in <utility>	2022-11 (Kona)	Complete	16
LWG3795	Self-move-assignment of std::future and std::shared_future have unimplementable postconditions	2022-11 (Kona)
LWG3796	movable-box as member should use default-initialization instead of copy-initialization	2022-11 (Kona)
LWG3798	Rvalue reference and iterator_category	2022-11 (Kona)	Partial		join_with_view, zip_transform_view, and adjacent_transform_view haven’t been done yet since these types aren’t implemented yet
LWG3801	cartesian_product_view::iterator::distance-from ignores the size of last underlying range	2022-11 (Kona)
LWG3814	Add freestanding items requested by NB comments	2022-11 (Kona)
LWG3816	flat_map and flat_multimap should impose sequence container requirements	2022-11 (Kona)
LWG3817	Missing preconditions on forward_list modifiers	2022-11 (Kona)
LWG3818	Exposition-only concepts are not described in library intro	2022-11 (Kona)	Nothing To Do
LWG3822	Avoiding normalization in filesystem::weakly_canonical	2022-11 (Kona)
LWG3823	Unnecessary precondition for is_aggregate	2022-11 (Kona)	Nothing To Do
LWG3824	Number of bind placeholders is underspecified	2022-11 (Kona)	Nothing To Do
LWG3826	Redundant specification [for overload of yield_value]	2022-11 (Kona)	Nothing To Do
LWG2195	Missing constructors for match_results	2023-02 (Issaquah)
LWG2295	Locale name when the provided Facet is a nullptr	2023-02 (Issaquah)
LWG3032	ValueSwappable requirement missing for push_heap and make_heap	2023-02 (Issaquah)
LWG3085	char_traits::copy precondition too weak	2023-02 (Issaquah)
LWG3664	LWG 3392 broke std::ranges::distance(a, a+3)	2023-02 (Issaquah)
LWG3720	Restrict the valid types of arg-id for width and precision in std-format-spec	2023-02 (Issaquah)	Complete	17
LWG3756	Is the std::atomic_flag class signal-safe?	2023-02 (Issaquah)
LWG3769	basic_const_iterator::operator== causes infinite constraint recursion	2023-02 (Issaquah)
LWG3807	The feature test macro for ranges::find_last should be renamed	2023-02 (Issaquah)
LWG3811	views::as_const on ref_view<T> should return ref_view<const T>	2023-02 (Issaquah)
LWG3820	cartesian_product_view::iterator::prev is not quite right	2023-02 (Issaquah)
LWG3825	Missing compile-time argument id check in basic_format_parse_context::next_arg_id	2023-02 (Issaquah)	Complete	17
LWG3204	sub_match::swap only swaps the base class	2023-02 (Issaquah)	Complete	17
LWG3733	ranges::to misuses cpp17-input-iterator	2023-02 (Issaquah)	Complete	17
LWG3742	deque::prepend_range needs to permute	2023-02 (Issaquah)
LWG3790	P1467 accidentally changed nexttoward’s signature	2023-02 (Issaquah)
LWG3819	reference_meows_from_temporary should not use is_meowible	2023-02 (Issaquah)
LWG3821	uses_allocator_construction_args should have overload for pair-like	2023-02 (Issaquah)	Complete	18
LWG3834	Missing constexpr for std::intmax_t math functions in <cinttypes>	2023-02 (Issaquah)
LWG3839	range_formatter’s set_separator, set_brackets, and underlying functions should be noexcept	2023-02 (Issaquah)	Complete	17
LWG3841	<version> should not be “all freestanding”	2023-02 (Issaquah)
LWG3842	Unclear wording for precision in chrono-format-spec	2023-02 (Issaquah)	Complete	16
LWG3848	adjacent_view, adjacent_transform_view and slide_view missing base accessor	2023-02 (Issaquah)
LWG3849	cartesian_product_view::iterator’s default constructor is overconstrained	2023-02 (Issaquah)
LWG3850	views::as_const on empty_view<T> should return empty_view<const T>	2023-02 (Issaquah)
LWG3851	chunk_view::inner-iterator missing custom iter_move and iter_swap	2023-02 (Issaquah)
LWG3853	basic_const_iterator<volatile int*>::operator-> is ill-formed	2023-02 (Issaquah)
LWG3857	basic_string_view should allow explicit conversion when only traits vary	2023-02 (Issaquah)	Complete	17
LWG3860	range_common_reference_t is missing	2023-02 (Issaquah)	Complete	17
LWG3866	Bad Mandates for expected::transform_error overloads	2023-02 (Issaquah)	Complete	17
LWG3867	Should std::basic_osyncstream’s move assignment operator be noexcept?	2023-02 (Issaquah)	Complete	18
LWG3441	Misleading note about calls to customization points	2023-02 (Issaquah)
LWG3622	Misspecified transitivity of equivalence in §[unord.req.general]	2023-02 (Issaquah)
LWG3631	basic_format_arg(T&&) should use remove_cvref_t<T> throughout	2023-02 (Issaquah)	Complete	17
LWG3645	resize_and_overwrite is overspecified to call its callback with lvalues	2023-02 (Issaquah)	Complete	14
LWG3655	The INVOKE operation and union types	2023-02 (Issaquah)	Complete	18
LWG3723	priority_queue::push_range needs to append_range	2023-02 (Issaquah)	Complete	17
LWG3734	Inconsistency in inout_ptr and out_ptr for empty case	2023-02 (Issaquah)	Complete	19
LWG3772	repeat_view’s piecewise constructor is missing Postconditions	2023-02 (Issaquah)	Complete	17
LWG3786	Flat maps’ deduction guide needs to default Allocator to be useful	2023-02 (Issaquah)
LWG3803	flat_foo constructors taking KeyContainer lack KeyCompare parameter	2023-02 (Issaquah)
LWG3810	CTAD for std::basic_format_args	2023-02 (Issaquah)	Complete	17
LWG3827	Deprecate <stdalign.h> and <stdbool.h> macros	2023-02 (Issaquah)
LWG3828	Sync intmax_t and uintmax_t with C2x	2023-02 (Issaquah)	Nothing To Do
LWG3833	Remove specialization template<size_t N> struct formatter<const charT[N], charT>	2023-02 (Issaquah)	Complete	17
LWG3836	std::expected<bool, E1> conversion constructor expected(const expected<U, G>&) should take precedence over expected(U&&) with operator bool	2023-02 (Issaquah)	Complete	18
LWG3843	std::expected<T,E>::value() & assumes E is copy constructible	2023-02 (Issaquah)	Complete	17
LWG3847	ranges::to can still return views	2023-02 (Issaquah)	Complete	17
LWG3862	basic_const_iterator’s common_type specialization is underconstrained	2023-02 (Issaquah)
LWG3865	Sorting a range of pairs	2023-02 (Issaquah)	Complete	17
LWG3869	Deprecate std::errc constants related to UNIX STREAMS	2023-02 (Issaquah)	Complete	19
LWG3870	Remove voidify	2023-02 (Issaquah)	Complete	20
LWG3871	Adjust note about terminate	2023-02 (Issaquah)
LWG3872	basic_const_iterator should have custom iter_move	2023-02 (Issaquah)
LWG3875	std::ranges::repeat_view<T, IntegerClass>::iterator may be ill-formed	2023-02 (Issaquah)	Complete	17
LWG3876	Default constructor of std::layout_XX::mapping misses precondition	2023-02 (Issaquah)
LWG3877	Incorrect constraints on const-qualified monadic overloads for std::expected	2023-02 (Issaquah)	Complete	17
LWG3878	import std; should guarantee initialization of standard iostreams objects	2023-02 (Issaquah)
LWG3879	erase_if for flat_{,multi}set is incorrectly specified	2023-02 (Issaquah)
LWG3880	Clarify operator+= complexity for {chunk,stride}_view::iterator	2023-02 (Issaquah)
LWG3881	Incorrect formatting of container adapters backed by std::string	2023-02 (Issaquah)	Complete	17