libc++ C++17 Status

Overview

In November 2014, the C++ standard committee created a draft for the next version of the C++ standard, initially known as “C++1z”. In February 2017, the C++ standard committee approved this draft, and sent it to ISO for approval as C++17.

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 #	Group	Paper Name	Meeting	Status	First released version
N3911	LWG	TransformationTrait Alias void_t.	Urbana	Complete	3.6
N4089	LWG	Safe conversions in unique_ptr<T[]>.	Urbana	In Progress	3.9
N4169	LWG	A proposal to add invoke function template	Urbana	Complete	3.7
N4190	LWG	Removing auto_ptr, random_shuffle(), And Old <functional> Stuff.	Urbana	Complete	15.0
N4258	LWG	Cleaning-up noexcept in the Library.	Urbana	In Progress	3.7
N4259	CWG	Wording for std::uncaught_exceptions	Urbana	Complete	3.7
N4277	LWG	TriviallyCopyable reference_wrapper.	Urbana	Complete	3.2
N4279	LWG	Improved insertion interface for unique-key maps.	Urbana	Complete	3.7
N4280	LWG	Non-member size() and more	Urbana	Complete	3.6
N4284	LWG	Contiguous Iterators.	Urbana	Complete	3.6
N4285	CWG	Cleanup for exception-specification and throw-expression.	Urbana	Complete	4.0
N4387	LWG	improving pair and tuple	Lenexa	Complete	4.0
N4389	LWG	bool_constant	Lenexa	Complete	3.7
N4508	LWG	shared_mutex for C++17	Lenexa	Complete	3.7
N4366	LWG	LWG 2228 missing SFINAE rule	Lenexa	Complete	3.1
N4510	LWG	Minimal incomplete type support for standard containers, revision 4	Lenexa	Complete	3.6
P0004R1	LWG	Remove Deprecated iostreams aliases.	Kona	Complete	3.8
P0006R0	LWG	Adopt Type Traits Variable Templates for C++17.	Kona	Complete	3.8
P0092R1	LWG	Polishing <chrono>	Kona	Complete	3.8
P0007R1	LWG	Constant View: A proposal for a std::as_const helper function template.	Kona	Complete	3.8
P0156R0	LWG	Variadic lock_guard(rev 3).	Kona	Reverted in Kona	3.9
P0074R0	LWG	Making std::owner_less more flexible	Kona	Complete	3.8
P0013R1	LWG	Logical type traits rev 2	Kona	Complete	3.8
P0024R2	LWG	The Parallelism TS Should be Standardized	Jacksonville	Partial
P0226R1	LWG	Mathematical Special Functions for C++17	Jacksonville
P0220R1	LWG	Adopt Library Fundamentals V1 TS Components for C++17	Jacksonville	Complete	16.0
P0218R1	LWG	Adopt the File System TS for C++17	Jacksonville	Complete	7.0
P0033R1	LWG	Re-enabling shared_from_this	Jacksonville	Complete	3.9
P0005R4	LWG	Adopt not_fn from Library Fundamentals 2 for C++17	Jacksonville	Complete	3.9
P0152R1	LWG	constexpr atomic::is_always_lock_free	Jacksonville	Complete	3.9
P0185R1	LWG	Adding [nothrow-]swappable traits	Jacksonville	Complete	3.9
P0253R1	LWG	Fixing a design mistake in the searchers interface	Jacksonville	Complete	3.9
P0025R0	LWG	An algorithm to “clamp” a value between a pair of boundary values	Jacksonville	Complete	3.9
P0154R1	LWG	constexpr std::hardware_{constructive,destructive}_interference_size	Jacksonville	Partial [3]	15.0
P0030R1	LWG	Proposal to Introduce a 3-Argument Overload to std::hypot	Jacksonville	Complete	3.9
P0031R0	LWG	A Proposal to Add Constexpr Modifiers to reverse_iterator, move_iterator, array and Range Access	Jacksonville	Complete	4.0
P0272R1	LWG	Give std::string a non-const .data() member function	Jacksonville	Complete	3.9
P0077R2	LWG	is_callable, the missing INVOKE related trait	Jacksonville	Complete	3.9
p0032r3	LWG	Homogeneous interface for variant, any and optional	Oulu	Complete	4.0
p0040r3	LWG	Extending memory management tools	Oulu	Complete	4.0
p0063r3	LWG	C++17 should refer to C11 instead of C99	Oulu	Complete	7.0
p0067r3	LWG	Elementary string conversions	Oulu	Now P0067R5	n/a
p0083r3	LWG	Splicing Maps and Sets	Oulu	Complete	8.0
p0084r2	LWG	Emplace Return Type	Oulu	Complete	4.0
p0088r3	LWG	Variant: a type-safe union for C++17	Oulu	Complete	4.0
p0137r1	CWG	Core Issue 1776: Replacement of class objects containing reference members	Oulu	Complete	6.0
p0163r0	LWG	shared_ptr::weak_type	Oulu	Complete	3.9
p0174r2	LWG	Deprecating Vestigial Library Parts in C++17	Oulu	Complete	15.0
p0175r1	LWG	Synopses for the C library	Oulu
p0180r2	LWG	Reserve a New Library Namespace for Future Standardization	Oulu	Nothing To Do	n/a
p0181r1	LWG	Ordered by Default	Oulu	Removed in Kona	n/a
p0209r2	LWG	make_from_tuple: apply for construction	Oulu	Complete	3.9
p0219r1	LWG	Relative Paths for Filesystem	Oulu	Complete	7.0
p0254r2	LWG	Integrating std::string_view and std::string	Oulu	Complete	4.0
p0258r2	LWG	has_unique_object_representations	Oulu	Complete	6.0
p0295r0	LWG	Adopt Selected Library Fundamentals V2 Components for C++17	Oulu	Complete	4.0
p0302r1	LWG	Removing Allocator Support in std::function	Oulu	Complete	4.0
p0307r2	LWG	Making Optional Greater Equal Again	Oulu	Complete	4.0
p0336r1	LWG	Better Names for Parallel Execution Policies in C++17	Oulu	Complete	17.0
p0337r0	LWG	Delete operator= for polymorphic_allocator	Oulu	Complete	3.9
p0346r1	LWG	A <random> Nomenclature Tweak	Oulu	Complete	3.9
p0358r1	LWG	Fixes for not_fn	Oulu	Complete	3.9
p0371r1	LWG	Temporarily discourage memory_order_consume	Oulu	Nothing To Do	n/a
p0392r0	LWG	Adapting string_view by filesystem paths	Oulu	Complete	4.0
p0393r3	LWG	Making Variant Greater Equal	Oulu	Complete	4.0
P0394r4	LWG	Hotel Parallelifornia: terminate() for Parallel Algorithms Exception Handling	Oulu	Complete	17.0
P0003R5	LWG	Removing Deprecated Exception Specifications from C++17	Issaquah	Complete	5.0
P0067R5	LWG	Elementary string conversions, revision 5	Issaquah	Partial [1]
P0403R1	LWG	Literal suffixes for basic_string_view	Issaquah	Complete	4.0
P0414R2	LWG	Merging shared_ptr changes from Library Fundamentals to C++17	Issaquah	Complete	11.0
P0418R2	LWG	Fail or succeed: there is no atomic lattice	Issaquah
P0426R1	LWG	Constexpr for std::char_traits	Issaquah	Complete	4.0
P0435R1	LWG	Resolving LWG Issues re common_type	Issaquah	Complete	4.0
P0502R0	LWG	Throwing out of a parallel algorithm terminates - but how?	Issaquah
P0503R0	LWG	Correcting library usage of “literal type”	Issaquah	Complete	4.0
P0504R0	LWG	Revisiting in-place tag types for any/optional/variant	Issaquah	Complete	4.0
P0505R0	LWG	Wording for GB 50 - constexpr for chrono	Issaquah	Complete	4.0
P0508R0	LWG	Wording for GB 58 - structured bindings for node_handles	Issaquah
P0509R1	LWG	Updating “Restrictions on exception handling”	Issaquah	Nothing To Do	n/a
P0510R0	LWG	Disallowing references, incomplete types, arrays, and empty variants	Issaquah	Complete	4.0
P0513R0	LWG	Poisoning the Hash	Issaquah	Complete	5.0
P0516R0	LWG	Clarify That shared_future’s Copy Operations have Wide Contracts	Issaquah	Complete	4.0
P0517R0	LWG	Make future_error Constructible	Issaquah	Complete	4.0
P0521R0	LWG	Proposed Resolution for CA 14 (shared_ptr use_count/unique)	Issaquah	Nothing To Do	n/a
P0156R2	LWG	Variadic Lock guard(rev 5)	Kona	Complete	5.0
P0270R3	CWG	Removing C dependencies from signal handler wording	Kona
P0298R3	CWG	A byte type definition	Kona	Complete	5.0
P0317R1	LWG	Directory Entry Caching for Filesystem	Kona	Complete	7.0
P0430R2	LWG	File system library on non-POSIX-like operating systems	Kona	Complete	7.0
P0433R2	LWG	Toward a resolution of US7 and US14: Integrating template deduction for class templates into the standard library	Kona	Complete	14.0
P0452R1	LWG	Unifying <numeric> Parallel Algorithms	Kona	Partial [4]
P0467R2	LWG	Iterator Concerns for Parallel Algorithms	Kona	Partial
P0492R2	LWG	Proposed Resolution of C++17 National Body Comments for Filesystems	Kona	Complete	7.0
P0518R1	LWG	Allowing copies as arguments to function objects given to parallel algorithms in response to CH11	Kona	Nothing To Do
P0523R1	LWG	Wording for CH 10: Complexity of parallel algorithms	Kona	Nothing To Do
P0548R1	LWG	common_type and duration	Kona	Complete	5.0
P0558R1	LWG	Resolving atomic<T> named base class inconsistencies	Kona	Complete
P0574R1	LWG	Algorithm Complexity Constraints and Parallel Overloads	Kona	Nothing To Do
P0599R1	LWG	noexcept for hash functions	Kona	Complete	5.0
P0604R0	LWG	Resolving GB 55, US 84, US 85, US 86	Kona	Complete
P0607R0	LWG	Inline Variables for the Standard Library	Kona	In Progress [2]	6.0
P0618R0	LWG	Deprecating <codecvt>	Kona	Complete	15.0
P0623R0	LWG	Final C++17 Parallel Algorithms Fixes	Kona	Nothing To Do
P0682R1	LWG	Repairing elementary string conversions	Toronto
P0739R0	LWG	Some improvements to class template argument deduction integration into the standard library	Toronto	Complete	5.0

Note

[1]

P0067: std::(to|from)_chars for integrals has been available since version 7.0. std::to_chars for float and double since version 14.0 std::to_chars for long double uses the implementation for double.

[2]

P0607: The parts of P0607 that are not done are the <regex> bits.

[3]

P0154: This is currently not implemented for clang because clang does not implement the required macros.

[4]

P0452: The changes to std::transform_inclusive_scan and std::transform_exclusive_scan have not yet been implemented.

Library Working Group Issues Status

Issue #	Issue Name	Meeting	Status	First released version
2016	Allocators must be no-throw swappable	Urbana	Complete
2118	unique_ptr for array does not support cv qualification conversion of actual argument	Urbana	Complete
2170	Aggregates cannot be DefaultConstructible	Urbana	Complete
2308	Clarify container destructor requirements w.r.t. std::array	Urbana	Complete
2340	Replacement allocation functions declared as inline	Urbana	Complete
2354	Unnecessary copying when inserting into maps with braced-init syntax	Urbana	Complete
2377	std::align requirements overly strict	Urbana	Complete
2396	underlying_type doesn’t say what to do for an incomplete enumeration type	Urbana	Complete
2399	shared_ptr‘s constructor from unique_ptr should be constrained	Urbana	Complete
2400	shared_ptr‘s get_deleter() should use addressof()	Urbana	Complete
2401	std::function needs more noexcept	Urbana	Complete
2404	mismatch()‘s complexity needs to be updated	Urbana	Complete
2408	SFINAE-friendly common_type / iterator_traits is missing in C++14	Urbana	Complete
2106	move_iterator wrapping iterators returning prvalues	Urbana	Complete
2129	User specializations of std::initializer_list	Urbana	Complete
2212	tuple_size for const pair request <tuple> header	Urbana	Complete
2217	operator==(sub_match, string) slices on embedded ‘0’s	Urbana	Complete
2230	“see below” for initializer_list constructors of unordered containers	Urbana	Complete
2233	bad_function_call::what() unhelpful	Urbana	Complete
2266	vector and deque have incorrect insert requirements	Urbana	Complete
2325	minmax_element()‘s behavior differing from max_element()‘s should be noted	Urbana	Complete
2361	Apply 2299 resolution throughout library	Urbana	Complete
2365	Missing noexcept in shared_ptr::shared_ptr(nullptr_t)	Urbana	Complete
2376	bad_weak_ptr::what() overspecified	Urbana	Complete
2387	More nested types that must be accessible and unambiguous	Urbana	Complete
2059	C++0x ambiguity problem with map::erase	Lenexa	Complete
2063	Contradictory requirements for string move assignment	Lenexa	Complete
2076	Bad CopyConstructible requirement in set constructors	Lenexa	Complete
2160	Unintended destruction ordering-specification of resize	Lenexa	Complete
2168	Inconsistent specification of uniform_real_distribution constructor	Lenexa	Complete
2239	min/max/minmax requirements	Lenexa	Complete
2364	deque and vector pop_back don’t specify iterator invalidation requirements	Lenexa	Complete
2369	constexpr max(initializer_list) vs max_element	Lenexa	Complete
2378	Behaviour of standard exception types	Lenexa	Complete
2403	stof() should call strtof() and wcstof()	Lenexa	Complete
2406	negative_binomial_distribution should reject p == 1	Lenexa	Complete
2407	packaged_task(allocator_arg_t, const Allocator&, F&&) should neither be constrained nor explicit	Lenexa	Complete
2411	shared_ptr is only contextually convertible to bool	Lenexa	Complete
2415	Inconsistency between unique_ptr and shared_ptr	Lenexa	Complete
2420	function<void(ArgTypes…)> does not discard the return value of the target object	Lenexa	Complete
2425	operator delete(void*, size_t) doesn’t invalidate pointers sufficiently	Lenexa	Complete
2427	Container adaptors as sequence containers, redux	Lenexa	Complete
2428	“External declaration” used without being defined	Lenexa	Complete
2433	uninitialized_copy()/etc. should tolerate overloaded operator&	Lenexa	Complete
2434	shared_ptr::use_count() is efficient	Lenexa	Complete
2437	iterator_traits::reference can and can’t be void	Lenexa	Complete
2438	std::iterator inheritance shouldn’t be mandated	Lenexa	Complete
2439	unique_copy() sometimes can’t fall back to reading its output	Lenexa	Complete
2440	seed_seq::size() should be noexcept	Lenexa	Complete
2442	call_once() shouldn’t DECAY_COPY()	Lenexa	Complete
2448	Non-normative Container destructor specification	Lenexa	Complete
2454	Add raw_storage_iterator::base() member	Lenexa	Complete
2455	Allocator default construction should be allowed to throw	Lenexa	Complete
2458	N3778 and new library deallocation signatures	Lenexa	Complete
2459	std::polar should require a non-negative rho	Lenexa	Complete
2464	try_emplace and insert_or_assign misspecified	Lenexa	Complete
2467	is_always_equal has slightly inconsistent default	Lenexa	Complete
2470	Allocator’s destroy function should be allowed to fail to instantiate	Lenexa	Complete
2482	[c.strings] Table 73 mentions nonexistent functions	Lenexa	Complete
2488	Placeholders should be allowed and encouraged to be constexpr	Lenexa	Complete
1169	num_get not fully compatible with strto*	Kona	Complete
2072	Unclear wording about capacity of temporary buffers	Kona	Complete
2101	Some transformation types can produce impossible types	Kona	Complete
2111	Which unexpected&#47;``terminate`` handler is called from the exception handling runtime?	Kona	Complete
2119	Missing hash specializations for extended integer types	Kona	Complete
2127	Move-construction with raw_storage_iterator	Kona	Complete
2133	Attitude to overloaded comma for iterators	Kona	Complete
2156	Unordered containers’ reserve(n) reserves for n-1 elements	Kona	Complete
2218	Unclear how containers use allocator_traits::construct()	Kona	Complete
2219	*INVOKE*-ing a pointer to member with a reference_wrapper as the object expression	Kona	Complete
2224	Ambiguous status of access to non-live objects	Kona	Complete
2234	assert() should allow usage in constant expressions	Kona	Complete
2244	Issue on basic_istream::seekg	Kona	Complete
2250	Follow-up On Library Issue 2207	Kona	Complete
2259	Issues in 17.6.5.5 rules for member functions	Kona	Complete
2273	regex_match ambiguity	Kona	Complete
2336	is_trivially_constructible/is_trivially_assignable traits are always false	Kona	Complete
2353	std::next is over-constrained	Kona	Complete
2367	pair and tuple are not correctly implemented for is_constructible with no args	Kona	Complete
2380	May <cstdlib> provide long ::abs(long) and long long ::abs(long long)?	Kona	Complete
2384	Allocator’s deallocate function needs better specification	Kona	Complete
2385	function::assign allocator argument doesn’t make sense	Kona	Complete
2435	reference_wrapper::operator()‘s Remark should be deleted	Kona	Complete
2447	Allocators and volatile-qualified value types	Kona	Complete
2462	std::ios_base::failure is overspecified	Kona	Complete
2466	allocator_traits::max_size() default behavior is incorrect	Kona	Complete
2469	Wrong specification of Requires clause of operator[] for map and unordered_map	Kona	Complete
2473	basic_filebuf‘s relation to C FILE semantics	Kona	Complete
2476	scoped_allocator_adaptor is not assignable	Kona	Complete
2477	Inconsistency of wordings in std::vector::erase() and std::deque::erase()	Kona	Complete
2483	throw_with_nested() should use is_final	Kona	Complete
2484	rethrow_if_nested() is doubly unimplementable	Kona	Complete
2485	get() should be overloaded for const tuple&&	Kona	Complete
2486	mem_fn() should be required to use perfect forwarding	Kona	Complete
2487	bind() should be const-overloaded, not cv-overloaded	Kona	Complete
2489	mem_fn() should be noexcept	Kona	Complete
2492	Clarify requirements for comp	Kona	Complete
2495	There is no such thing as an Exception Safety element	Kona	Complete
2192	Validity and return type of std::abs(0u) is unclear	Jacksonville	Complete
2276	Missing requirement on std::promise::set_exception	Jacksonville	Complete
2296	std::addressof should be constexpr	Jacksonville	Complete
2450	(greater|less|greater_equal|less_equal)<void> do not yield a total order for pointers	Jacksonville	Complete
2520	N4089 broke initializing unique_ptr<T[]> from a nullptr	Jacksonville	Complete
2522	[fund.ts.v2] Contradiction in set_default_resource specification	Jacksonville	Complete
2523	std::promise synopsis shows two set_value_at_thread_exit()‘s for no apparent reason	Jacksonville	Complete
2537	Constructors for priority_queue taking allocators should call make_heap	Jacksonville	Complete
2539	[fund.ts.v2] invocation_trait definition definition doesn’t work for surrogate call functions	Jacksonville
2545	Simplify wording for bind without explicitly specified return type	Jacksonville	Complete
2557	Logical operator traits are broken in the zero-argument case	Jacksonville	Complete
2558	[fund.ts.v2] Logical operator traits are broken in the zero-argument case	Jacksonville	Complete
2559	Error in LWG 2234’s resolution	Jacksonville	Complete
2560	is_constructible underspecified when applied to a function type	Jacksonville	Complete
2565	std::function‘s move constructor should guarantee nothrow for reference_wrappers and function pointers	Jacksonville	Complete
2566	Requirements on the first template parameter of container adaptors	Jacksonville	Complete
2571	§[map.modifiers]/2 imposes nonsensical requirement on insert(InputIterator, InputIterator)	Jacksonville	Complete
2572	The remarks for shared_ptr::operator* should apply to cv-qualified void as well	Jacksonville	Complete
2574	[fund.ts.v2] std::experimental::function::operator=(F&&) should be constrained	Jacksonville	Complete
2575	[fund.ts.v2] experimental::function::assign should be removed	Jacksonville
2576	istream_iterator and ostream_iterator should use std::addressof	Jacksonville	Complete
2577	{shared,unique}_lock should use std::addressof	Jacksonville	Complete
2579	Inconsistency wrt Allocators in basic_string assignment vs. basic_string::assign	Jacksonville	Complete
2581	Specialization of <type_traits> variable templates should be prohibited	Jacksonville	Complete
2582	§[res.on.functions]/2’s prohibition against incomplete types shouldn’t apply to type traits	Jacksonville	Complete
2583	There is no way to supply an allocator for basic_string(str, pos)	Jacksonville	Complete
2585	forward_list::resize(size_type, const value_type&) effects incorrect	Jacksonville	Complete
2586	Wrong value category used in scoped_allocator_adaptor::construct()	Jacksonville	Complete
2590	Aggregate initialization for std::array	Jacksonville	Complete
2181	Exceptions from seed sequence operations	Oulu	Complete
2309	mutex::lock() should not throw device_or_resource_busy	Oulu	Complete
2310	Public exposition only member in std::array	Oulu	Complete
2312	tuple’s constructor constraints need to be phrased more precisely	Oulu	Complete
2328	Rvalue stream extraction should use perfect forwarding	Oulu	Complete
2393	std::function’s Callable definition is broken	Oulu	Complete
2422	std::numeric_limits<T>::is_modulo description: “most machines” errata	Oulu	Complete
2426	Issue about compare_exchange	Oulu
2436	Comparators for associative containers should always be CopyConstructible	Oulu	Complete
2441	Exact-width atomic typedefs should be provided	Oulu	Complete
2451	[fund.ts.v2] optional should ‘forward’ T’s implicit conversions	Oulu	Nothing To Do
2509	[fund.ts.v2] any_cast doesn’t work with rvalue reference targets and cannot move with a value target	Oulu	Complete
2516	[fund.ts.v2] Public “exposition only” members in observer_ptr	Oulu
2542	Missing const requirements for associative containers	Oulu
2549	Tuple EXPLICIT constructor templates that take tuple parameters end up taking references to temporaries and will create dangling references	Oulu	Complete
2550	Wording of unordered container’s clear() method complexity	Oulu	Complete
2551	[fund.ts.v2] “Exception safety” cleanup in library fundamentals required	Oulu	Complete
2555	[fund.ts.v2] No handling for over-aligned types in optional	Oulu	Complete
2573	[fund.ts.v2] std::hash<std::experimental::shared_ptr> does not work for arrays	Oulu
2596	vector::data() should use addressof	Oulu	Complete
2667	path::root_directory() description is confusing	Oulu	Complete
2669	recursive_directory_iterator effects refers to non-existent functions	Oulu	Complete
2670	system_complete refers to undefined variable ‘base’	Oulu	Complete
2671	Errors in Copy	Oulu	Complete
2673	status() effects cannot be implemented as specified	Oulu	Complete
2674	Bidirectional iterator requirement on path::iterator is very expensive	Oulu	Complete
2683	filesystem::copy() says “no effects”	Oulu	Complete
2684	priority_queue lacking comparator typedef	Oulu	Complete
2685	shared_ptr deleters must not throw on move construction	Oulu	Complete
2687	{inclusive,exclusive}_scan misspecified	Oulu
2688	clamp misses preconditions and has extraneous condition on result	Oulu	Complete
2689	Parallel versions of std::copy and std::move shouldn’t be in order	Oulu	Nothing To Do
2698	Effect of assign() on iterators/pointers/references	Oulu	Complete
2704	recursive_directory_iterator’s members should require ‘*this is dereferenceable’	Oulu	Complete
2706	Error reporting for recursive_directory_iterator::pop() is under-specified	Oulu	Complete
2707	path construction and assignment should have “string_type&&” overloads	Oulu	Complete
2709	offsetof is unnecessarily imprecise	Oulu
2710	“Effects: Equivalent to …” doesn’t count “Synchronization:” as determined semantics	Oulu	Complete
2711	path is convertible from approximately everything under the sun	Oulu	Complete
2716	Specification of shuffle and sample disallows lvalue URNGs	Oulu	Complete
2718	Parallelism bug in [algorithms.parallel.exec] p2	Oulu
2719	permissions function should not be noexcept due to narrow contract	Oulu	Complete
2720	permissions function incorrectly specified for symlinks	Oulu	Complete
2721	remove_all has incorrect post conditions	Oulu	Complete
2723	Do directory_iterator and recursive_directory_iterator become the end iterator upon error?	Oulu	Complete
2724	The protected virtual member functions of memory_resource should be private	Oulu	Complete	16.0
2725	filesystem::exists(const path&, error_code&) error reporting	Oulu	Complete
2726	[recursive_]directory_iterator::increment(error_code&) is underspecified	Oulu	Complete
2727	Parallel algorithms with constexpr specifier	Oulu
2728	status(p).permissions() and symlink_status(p).permissions() are not specified	Oulu	Complete
2062	Effect contradictions w/o no-throw guarantee of std::function swaps	Issaquah	Complete
2166	Heap property underspecified?	Issaquah
2221	No formatted output operator for nullptr	Issaquah	Complete
2223	shrink_to_fit effect on iterator validity	Issaquah	Complete
2261	Are containers required to use their ‘pointer’ type internally?	Issaquah
2394	locale::name specification unclear - what is implementation-defined?	Issaquah	Complete
2460	LWG issue 2408 and value categories	Issaquah	Complete
2468	Self-move-assignment of library types	Issaquah
2475	Allow overwriting of std::basic_string terminator with charT() to allow cleaner interoperation with legacy APIs	Issaquah	Complete
2503	multiline option should be added to syntax_option_type	Issaquah	Complete
2510	Tag types should not be DefaultConstructible	Issaquah	Complete
2514	Type traits must not be final	Issaquah	Complete
2518	[fund.ts.v2] Non-member swap for propagate_const should call member swap	Issaquah	Complete
2519	Iterator operator-= has gratuitous undefined behaviour	Issaquah	Complete
2521	[fund.ts.v2] weak_ptr’s converting move constructor should be modified as well for array support	Issaquah
2525	[fund.ts.v2] get_memory_resource should be const and noexcept	Issaquah
2527	[fund.ts.v2] ALLOCATOR_OF for function::operator= has incorrect default	Issaquah
2531	future::get should explicitly state that the shared state is released	Issaquah	Nothing To Do
2534	Constrain rvalue stream operators	Issaquah	Complete
2536	What should <complex.h> do?	Issaquah	Complete
2540	unordered_multimap::insert hint iterator	Issaquah	Complete
2543	LWG 2148 (hash support for enum types) seems under-specified	Issaquah	Complete
2544	istreambuf_iterator(basic_streambuf<charT, traits>* s) effects unclear when s is 0	Issaquah	Complete
2556	Wide contract for future::share()	Issaquah	Complete
2562	Consistent total ordering of pointers by comparison functors	Issaquah
2567	Specification of logical operator traits uses BaseCharacteristic, which is defined only for UnaryTypeTraits and BinaryTypeTraits	Issaquah	Complete
2568	[fund.ts.v2] Specification of logical operator traits uses BaseCharacteristic, which is defined only for UnaryTypeTraits and BinaryTypeTraits	Issaquah	Complete	15.0
2569	conjunction and disjunction requirements are too strict	Issaquah	Complete	15.0
2570	[fund.ts.v2] conjunction and disjunction requirements are too strict	Issaquah
2578	Iterator requirements should reference iterator traits	Issaquah	Complete
2584	<regex> ECMAScript IdentityEscape is ambiguous	Issaquah
2587	“Convertible to bool” requirement in conjunction and disjunction	Issaquah	Resolved by 2567
2588	[fund.ts.v2] “Convertible to bool” requirement in conjunction and disjunction	Issaquah	Resolved by 2568
2589	match_results can’t satisfy the requirements of a container	Issaquah	Complete
2591	std::function’s member template target() should not lead to undefined behaviour	Issaquah	Complete
2598	addressof works on temporaries	Issaquah	Complete
2664	operator/ (and other append) semantics not useful if argument has root	Issaquah	Complete
2665	remove_filename() post condition is incorrect	Issaquah	Complete
2672	Should is_empty use error_code in its specification?	Issaquah	Complete
2678	std::filesystem enum classes overspecified	Issaquah	Complete
2679	Inconsistent Use of Effects and Equivalent To	Issaquah	Complete
2680	Add “Equivalent to” to filesystem	Issaquah	Complete
2681	filesystem::copy() cannot copy symlinks	Issaquah	Complete
2682	filesystem::copy() won’t create a symlink to a directory	Issaquah	Complete
2686	Why is std::hash specialized for error_code, but not error_condition?	Issaquah	Complete
2694	Application of LWG 436 accidentally deleted definition of “facet”	Issaquah	Complete
2696	Interaction between make_shared and enable_shared_from_this is underspecified	Issaquah	Nothing To Do
2699	Missing restriction in [numeric.requirements]	Issaquah	Complete
2712	copy_file(from, to, …) has a number of unspecified error conditions	Issaquah	Complete
2722	equivalent incorrectly specifies throws clause	Issaquah	Complete
2729	Missing SFINAE on std::pair::operator=	Issaquah	Complete
2732	Questionable specification of path::operator/= and path::append	Issaquah	Complete
2733	[fund.ts.v2] gcd / lcm and bool	Issaquah	Complete
2735	std::abs(short), std::abs(signed char) and others should return int instead of double in order to be compatible with C++98 and C	Issaquah	Complete
2736	nullopt_t insufficiently constrained	Issaquah	Complete
2738	is_constructible with void types	Issaquah	Complete
2739	Issue with time_point non-member subtraction with an unsigned duration	Issaquah	Complete
2740	constexpr optional<T>::operator->	Issaquah	Complete
2742	Inconsistent string interface taking string_view	Issaquah	Complete
2744	any’s in_place constructors	Issaquah	Complete
2745	[fund.ts.v2] Implementability of LWG 2451	Issaquah	Complete
2747	Possibly redundant std::move in [alg.foreach]	Issaquah	Complete
2748	swappable traits for optionals	Issaquah	Complete
2749	swappable traits for variants	Issaquah	Complete
2750	[fund.ts.v2] LWG 2451 conversion constructor constraint	Issaquah	Nothing To Do
2752	“Throws:” clauses of async and packaged_task are unimplementable	Issaquah	Nothing To Do
2755	[string.view.io] uses non-existent basic_string_view::to_string function	Issaquah	Complete
2756	C++ WP optional<T> should ‘forward’ T’s implicit conversions	Issaquah	Complete
2758	std::string{}.assign(“ABCDE”, 0, 1) is ambiguous	Issaquah	Complete
2759	gcd / lcm and bool for the WP	Issaquah	Complete
2760	non-const basic_string::data should not invalidate iterators	Issaquah	Complete
2765	Did LWG 1123 go too far?	Issaquah	Complete
2767	not_fn call_wrapper can form invalid types	Issaquah	Complete
2769	Redundant const in the return type of any_cast(const any&)	Issaquah	Complete
2771	Broken Effects of some basic_string::compare functions in terms of basic_string_view	Issaquah	Complete
2773	Making std::ignore constexpr	Issaquah	Complete
2777	basic_string_view::copy should use char_traits::copy	Issaquah	Complete
2778	basic_string_view is missing constexpr	Issaquah	Complete
2260	Missing requirement for Allocator::pointer	Kona	Complete
2676	Provide filesystem::path overloads for File-based streams	Kona	Complete
2768	any_cast and move semantics	Kona	Complete
2769	Redundant const in the return type of any_cast(const any&)	Kona	Complete
2781	Contradictory requirements for std::function and std::reference_wrapper	Kona	Complete
2782	scoped_allocator_adaptor constructors must be constrained	Kona	Complete
2784	Resolution to LWG 2484 is missing “otherwise, no effects” and is hard to parse	Kona	Complete
2785	quoted should work with basic_string_view	Kona	Complete
2786	Annex C should mention shared_ptr changes for array support	Kona	Complete
2787	§[file_status.cons] doesn’t match class definition	Kona	Complete
2788	basic_string range mutators unintentionally require a default constructible allocator	Kona	Complete
2789	Equivalence of contained objects	Kona	Complete
2790	Missing specification of istreambuf_iterator::operator->	Kona	Complete
2794	Missing requirements for allocator pointers	Kona	Nothing To Do
2795	§[global.functions] provides incorrect example of ADL use	Kona	Complete
2796	tuple should be a literal type	Kona	Complete
2801	Default-constructibility of unique_ptr	Kona	Complete
2802	shared_ptr constructor requirements for a deleter	Kona	Complete
2804	Unconditional constexpr default constructor for istream_iterator	Kona	Complete
2806	Base class of bad_optional_access	Kona	Complete
2807	std::invoke should use std::is_nothrow_callable	Kona	Complete
2812	Range access is available with <string_view>	Kona	Complete
2824	list::sort should say that the order of elements is unspecified if an exception is thrown	Kona	Complete
2826	string_view iterators use old wording	Kona	Complete
2834	Resolution LWG 2223 is missing wording about end iterators	Kona	Complete
2835	LWG 2536 seems to misspecify <tgmath.h>	Kona	Complete
2837	gcd and lcm should support a wider range of input values	Kona	Complete
2838	is_literal_type specification needs a little cleanup	Kona	Complete
2842	in_place_t check for optional::optional(U&&) should decay U	Kona	Complete
2850	std::function move constructor does unnecessary work	Kona	Complete
2853	Possible inconsistency in specification of erase in [vector.modifiers]	Kona	Complete
2855	std::throw_with_nested(“string_literal”)	Kona	Complete
2857	{variant,optional,any}::emplace should return the constructed value	Kona	Complete
2861	basic_string should require that charT match traits::char_type	Kona	Complete
2866	Incorrect derived classes constraints	Kona	Nothing To Do
2868	Missing specification of bad_any_cast::what()	Kona	Complete
2872	Add definition for direct-non-list-initialization	Kona	Complete
2873	Add noexcept to several shared_ptr related functions	Kona	Complete
2874	Constructor shared_ptr::shared_ptr(Y*) should be constrained	Kona	Complete	13.0
2875	shared_ptr::shared_ptr(Y*, D, […]) constructors should be constrained	Kona	Complete
2876	shared_ptr::shared_ptr(const weak_ptr<Y>&) constructor should be constrained	Kona	Complete	14.0
2878	Missing DefaultConstructible requirement for istream_iterator default constructor	Kona	Complete
2890	The definition of ‘object state’ applies only to class types	Kona	Complete
2900	The copy and move constructors of optional are not constexpr	Kona	Complete
2903	The form of initialization for the emplace-constructors is not specified	Kona	Complete
2904	Make variant move-assignment more exception safe	Kona	Complete
2905	is_constructible_v<unique_ptr<P, D>, P, D const &> should be false when D is not copy constructible	Kona	Complete
2908	The less-than operator for shared pointers could do more	Kona	Complete
2911	An is_aggregate type trait is needed	Kona	Complete
2921	packaged_task and type-erased allocators	Kona	Complete
2934	optional<const T> doesn’t compare with T	Kona	Complete
2901	Variants cannot properly support allocators	Toronto	Complete
2955	to_chars / from_chars depend on std::string	Toronto	Resolved by P0682R1
2956	filesystem::canonical() still defined in terms of absolute(p, base)	Toronto	Complete