C++ Standard Library Issues List (Revision D126)

Reference ISO/IEC IS 14882:2024(E)

This document is the Table of Contents for the Library Active Issues List, Library Defect Reports and Accepted Issues, and Library Closed Issues List.

Revised 2025-11-08 at 03:10:52 UTC

Issue	Status	Section	Title	Proposed Resolution	Priority
2991⁽ⁱ⁾	Voting	22.6.3.2 [variant.ctor]	`variant` copy constructor missing `noexcept(see below)`	Yes
3090⁽ⁱ⁾	Voting	30.5.2 [time.duration.cons]	What is §[time.duration.cons]p4's "no overflow is induced in the conversion" intended to mean?	Yes	3
3343⁽ⁱ⁾	Immediate	32.7.3 [thread.condition.nonmember]	Ordering of calls to `unlock()` and `notify_all()` in Effects element of `notify_all_at_thread_exit()` should be reversed	Yes	3
3454⁽ⁱ⁾	Immediate	20.2.3 [pointer.traits]	`pointer_traits::pointer_to` should be `constexpr`	Yes	4
3627⁽ⁱ⁾	Voting	22.5.10 [optional.specalg]	Inconsistent specifications for `std::make_optional` overloads	Yes	3
4015⁽ⁱ⁾	Immediate	22.5.3.8 [optional.monadic]	LWG 3973 broke `const` overloads of `std::optional` monadic operations	Yes	1
4020⁽ⁱ⁾	Voting	23.7.3.3.2 [mdspan.extents.expo]	`extents::index-cast` weirdness	Yes
4136⁽ⁱ⁾	Voting	29.9.3 [linalg.general]	Specify behavior of [linalg] Hermitian algorithms on diagonal with nonzero imaginary part	Yes
4137⁽ⁱ⁾	Voting	29.9.14 [linalg.algs.blas2]	Fix Mandates, Preconditions, and Complexity elements of [linalg] algorithms	Yes
4166⁽ⁱ⁾	Voting	25.7.18.2 [range.concat.view]	`concat_view::end()` should be more constrained in order to support noncopyable iterators	Yes
4230⁽ⁱ⁾	Immediate	29.10.8.4 [simd.complex.access]	`simd<complex>::real/imag` is overconstrained	Yes	2
4243⁽ⁱ⁾	Voting	23.7.2.3 [span.objectrep]	`as_bytes`/`as_writable_bytes` is broken with `span<volatile T>`	Yes	4
4251⁽ⁱ⁾	Immediate	20.4.1.5 [indirect.assign]	Move assignment for `indirect` unnecessarily requires copy construction	Yes	1
4253⁽ⁱ⁾	Voting	24.5.3.3 [const.iterators.iterator]	`basic_const_iterator` should provide `iterator_type`	Yes
4255⁽ⁱ⁾	Voting	22.10.17.4.3 [func.wrap.move.ctor]	`move_only_function` constructor should recognize empty `copyable_function`s	Yes
4256⁽ⁱ⁾	Voting	22.10.17.6.3 [func.wrap.ref.ctor]	Incorrect constrains for `function_ref` constructors from `nontype_t`	Yes
4257⁽ⁱ⁾	Voting	30.7.9 [time.clock.local]	Stream insertion for `chrono::local_time` should be constrained	Yes
4260⁽ⁱ⁾	Immediate	33.2.1 [exec.queryable.general]	Query objects must be default constructible	Yes	2
4265⁽ⁱ⁾	Voting	26.10.16 [numeric.ops.midpoint]	`std::midpoint` should not accept `const bool`	Yes
4266⁽ⁱ⁾	Voting	23.7.3.4.7 [mdspan.layout.stride]	`layout_stride::mapping` should treat empty mappings as exhaustive	Yes
4269⁽ⁱ⁾	Voting	26.7.9 [alg.unique]	`unique_copy` passes arguments to its predicate backwards	Yes
4272⁽ⁱ⁾	Immediate	23.7.3.4 [mdspan.layout]	For `rank == 0`, `layout_stride` is atypically convertible	Yes	2
4274⁽ⁱ⁾	Voting	30.9.2 [time.hms.members]	The `chrono::hh_mm_ss` constructor is ill-formed for unsigned durations	Yes
4275⁽ⁱ⁾	Voting	23.7.3.2 [mdspan.syn]	`std::dynamic_extent` should also be defined in `<mdspan>`	Yes	3
4276⁽ⁱ⁾	Voting	23.3.3.5 [array.zero]	`front()` and `back()` are not hardened for zero-length `std::array`s	Yes
4280⁽ⁱ⁾	Voting	29.10.8.7 [simd.loadstore]	`simd::partial_load` uses undefined identifier `T`	Yes
4286⁽ⁱ⁾	Voting	17.3.2 [version.syn]	Some more feature-test macros for fully freestanding features are not marked freestanding	Yes
4291⁽ⁱ⁾	Voting	23.4.3.1 [map.overview]	`explicit map(const Allocator&)` should be `constexpr`	Yes
4292⁽ⁱ⁾	Voting	23.5.3.1 [unord.map.overview]	Unordered container local iterators should be constexpr iterators	Yes
4293⁽ⁱ⁾	Voting	23.7.2.2.4 [span.sub]	span::subspan/first/last chooses wrong constructor when T is const-qualified bool	Yes
4294⁽ⁱ⁾	Voting	22.9.2.2 [bitset.cons]	`bitset(const CharT*)` constructor needs to be constrained	Yes
4297⁽ⁱ⁾	Voting	26.4 [algorithm.syn]	Missing `permutable` constraint for iterator overloads in Parallel Range Algorithms	Yes
4299⁽ⁱ⁾	Voting	22.5.4.7 [optional.ref.monadic]	Missing Mandates: part in `optional<T&>::transform`	Yes
4300⁽ⁱ⁾	Voting	22.5.4.3 [optional.ref.assign]	Missing Returns: element in `optional<T&>::emplace`	Yes
4301⁽ⁱ⁾	Voting	32.7.4 [thread.condition.condvar]	`condition_variable{_any}::wait_{for, until}` should take timeout by value	Yes
4302⁽ⁱ⁾	Immediate	29.9.13.8 [linalg.algs.blas1.ssq]	Problematic `vector_sum_of_squares` wording	Yes	1
4304⁽ⁱ⁾	Immediate	22.5.4.6 [optional.ref.observe]	`std::optional<NonReturnable&>` is ill-formed due to `value_or`	Yes	1
4305⁽ⁱ⁾	Voting	17.12.7 [compare.type]	Missing user requirements on `type_order` template	Yes
4308⁽ⁱ⁾	Immediate	22.5.4.5 [optional.ref.iterators]	`std::optional<T&>::iterator` can't be a contiguous iterator for some `T`	Yes	1
4312⁽ⁱ⁾	Voting	20.2.8.2 [allocator.uses.construction]	Const and value category mismatch for `allocator_arg_t`/`allocator_arg` in the description of uses-allocator construction	Yes
4315⁽ⁱ⁾	Voting	29.9.13.9 [linalg.algs.blas1.nrm2]	Insufficient specification of `vector_two_norm` and `matrix_frob_norm`	Yes
4316⁽ⁱ⁾	Immediate	21.4.13 [meta.reflection.substitute]	`{can_}substitute` specification is ill-formed	Yes	1
4317⁽ⁱ⁾	Voting	16.4.4.2 [utility.arg.requirements]	The meaning of "resource" in the Cpp17Destructible requirements is undefined	Yes
4318⁽ⁱ⁾	Voting	23.3.9.6 [hive.erasure]	Have `hive::erase_if` reevaluate `end()` to avoid UB	Yes
4328⁽ⁱ⁾	Voting	33.6 [exec.sched]	Remove note in §[exec.sched] regarding waiting for completion of scheduled operations	Yes
4340⁽ⁱ⁾	Voting	33.13.6.5 [task.promise]	`task::promise_type::unhandled_stopped()` should be `noexcept`	Yes
4341⁽ⁱ⁾	Voting	33.13.6.2 [task.class]	Missing rvalue reference qualification for `task::connect()`	Yes
4342⁽ⁱ⁾	Voting	33.13.5 [exec.task.scheduler]	Missing rvalue reference qualification for `task_scheduler::ts-sender::connect()`	Yes
4343⁽ⁱ⁾	Voting	33.13.6.2 [task.class]	Missing default template arguments for `task`	Yes
4345⁽ⁱ⁾	Voting	33.13.6.5 [task.promise]	`task::promise_type::return_value` default template parameter	Yes
4346⁽ⁱ⁾	Voting	33.13.6.5 [task.promise]	`task::promise_type::return_void`/`value` lack a specification	Yes
4349⁽ⁱ⁾	Voting	33.13.6.5 [task.promise]	`task` is not actually started lazily	Yes
4351⁽ⁱ⁾	Voting	23.7.2.1 [span.syn]	`integral-constant-like` needs more `remove_cvref_t`	Yes
4358⁽ⁱ⁾	Immediate	33.13.1 [exec.as.awaitable]	§[exec.as.awaitable] is using "Preconditions:" when it should probably be described in the constraint	Yes	2
4360⁽ⁱ⁾	Immediate	33.13.1 [exec.as.awaitable]	`awaitable-sender` concept should qualify use of `awaitable-receiver` type	Yes	2
4366⁽ⁱ⁾	Voting	22.8.6.8 [expected.object.eq]	Heterogeneous comparison of `expected` may be ill-formed	Yes
4369⁽ⁱ⁾	Immediate	33.9.12.9 [exec.then]	`check-types` function for `upon_error` and `upon_stopped` is wrong	Yes	2
4370⁽ⁱ⁾	Voting	22.5.9 [optional.comp.with.t]	Comparison of `optional<T>` to `T` may be ill-formed	Yes
4372⁽ⁱ⁾	Voting	23.7.3.4.8.1 [mdspan.layout.leftpad.overview]	Weaken Mandates: for dynamic padding values in padded layouts	Yes
4375⁽ⁱ⁾	Voting	29.10.8.15 [simd.bit]	`std::simd::bit_ceil` should not be `noexcept`	Yes
4376⁽ⁱ⁾	Immediate	29.10.9.4 [simd.mask.unary]	ABI tag in return type of [simd.mask.unary] is overconstrained	Yes	1
4377⁽ⁱ⁾	Voting	32.5.7.2 [atomics.ref.ops]	Misleading note about lock-free property of `std::atomic_ref`	Yes
4382⁽ⁱ⁾	Voting	29.10.9.2 [simd.mask.ctor]	The `simd::basic_mask(bool)` overload needs to be more constrained	Yes
4383⁽ⁱ⁾	Immediate	21.3.5 [const.wrap.class]	`constant_wrapper`'s pseudo-mutators are underconstrained	Yes	1
4384⁽ⁱ⁾	Voting	23.6.11.2 [flat.set.defn]	`flat_set::erase(iterator)` is underconstrained	Yes
4388⁽ⁱ⁾	Immediate	17.14.2 [cstdarg.syn]	Align new definition of `va_start` with C23	Yes	1
4396⁽ⁱ⁾	Immediate	23.2.4 [sequence.reqmts]	Improve `inplace_vector(from_range_t, R&& rg)`	Yes	3
4398⁽ⁱ⁾	Voting	23.6.2 [queue.syn]	`enable_nonlocking_formatter_optimization` should be disabled for container adaptors	Yes	2
4399⁽ⁱ⁾	Voting	28.5.9 [format.tuple]	`enable_nonlocking_formatter_optimization` for `pair` and `tuple` needs `remove_cvref_t`	Yes
4403⁽ⁱ⁾	Voting	29.10.7.2 [simd.ctor]	`simd::basic_vec` CTAD misses difference type casting	Yes
4407⁽ⁱ⁾	Voting	29.10.7.2 [simd.ctor]	`constexpr-wrapper-like` needs `remove_cvref_t` in `simd::basic_vec` constructor	Yes
4412⁽ⁱ⁾	Voting	29.10.3 [simd.syn]	Fix declaration of `zero_element` and `uninit_element`	Yes
4413⁽ⁱ⁾	Voting	29.10.4 [simd.traits]	Unused/left-over `simd::alignment` specialization for `basic_mask`	Yes
4415⁽ⁱ⁾	Voting	33.13.6.5 [task.promise]	`task::promise_type::uncaught_exception` seems to be misnamed	Yes
4416⁽ⁱ⁾	Voting	21.4.1 [meta.syn]	`<meta>` should include `<compare>`	Yes
4420⁽ⁱ⁾	Immediate	29.10 [simd]	§[simd] conversions (constructor, load, stores, gather, and scatter) are incorrectly constrained for `<stdfloat>` types	Yes	1
4422⁽ⁱ⁾	Voting	21.4.8 [meta.reflection.access.context]	`meta::access_context` should be a consteval-only type	Yes	2
4423⁽ⁱ⁾	Voting	21.4.16 [meta.reflection.define.aggregate]	`meta::data_member_spec` allows negative bit-field widths	Yes
4424⁽ⁱ⁾	Immediate	21.4.16 [meta.reflection.define.aggregate]	`meta::define_aggregate` should require a class type	Yes	1
4425⁽ⁱ⁾	Voting	22.10.17.6.5 [func.wrap.ref.deduct]	CTAD `function_ref` of data member pointer should produce `noexcept` signature	Yes
4426⁽ⁱ⁾	Voting	21.4.15 [meta.reflection.array]	Clarify what `meta::reflect_constant_string` considers a string literal	Yes
4427⁽ⁱ⁾	Immediate	21.4.7 [meta.reflection.queries]	`meta::dealias` needs to work with things that aren't entities	Yes
4428⁽ⁱ⁾	Immediate	21.4.9 [meta.reflection.access.queries]	Metafunctions should not be defined in terms of constant subexpressions	Yes
4429⁽ⁱ⁾	Immediate	21.4.11 [meta.reflection.layout]	`meta::alignment_of` should exclude data member description of bit-field	Yes
4430⁽ⁱ⁾	Immediate	28.2.3 [charconv.from.chars]	`from_chars` should not parse `"0b"` base prefixes	Yes
4431⁽ⁱ⁾	Immediate	20.2.2 [memory.syn]	Parallel `std::ranges::destroy` should allow exceptions	Yes
4432⁽ⁱ⁾	Immediate	21.4.3 [meta.define.static]	Clarify element initialization for `meta::reflect_constant_array`	Yes
4433⁽ⁱ⁾	Immediate	21.4.7 [meta.reflection.queries]	Incorrect query for C language linkage	Yes
4434⁽ⁱ⁾	Immediate	21.4.9 [meta.reflection.access.queries]	`meta::is_accessible` does not need to consider incomplete D	Yes
4435⁽ⁱ⁾	Immediate	21.4.6 [meta.reflection.names]	`meta::has_identifier` doesn't handle all types	Yes	2
4438⁽ⁱ⁾	Immediate	33.9.12.12 [exec.when.all]	Bad expression in [exec.when.all]	Yes
4439⁽ⁱ⁾	Immediate	22.5.4.4 [optional.ref.swap]	`std::optional<T&>::swap` possibly selects ADL-found `swap`	Yes
4440⁽ⁱ⁾	Immediate	17.3.2 [version.syn]	Forward declarations of entities need also in entries	Yes
4441⁽ⁱ⁾	Immediate	26.7.11 [alg.rotate]	`ranges::rotate` do not handle sized-but-not-sized-sentinel ranges correctly	Yes
4442⁽ⁱ⁾	Immediate	21.4.14 [meta.reflection.result]	Clarify `expr` and `fn` for `meta::reflect_object` and `meta::reflect_function`	Yes
4443⁽ⁱ⁾	Immediate	21.4.16 [meta.reflection.define.aggregate]	Clean up identifier comparisons in `meta::define_aggregate`	Yes
4444⁽ⁱ⁾	Immediate	26.7.5 [alg.replace]	Fix default template arguments for `ranges::replace` and `ranges::replace_if`	Yes
4445⁽ⁱ⁾	Immediate	33.13.5 [exec.task.scheduler]	`sch_` must not be in moved-from state	Yes
4446⁽ⁱ⁾	Immediate	33.13.5 [exec.task.scheduler]	Bad phrasing for `SCHED(s)`	Yes
4447⁽ⁱ⁾	Immediate	33.4 [execution.syn]	Remove unnecessary `sizeof…(Env) > 1` condition	Yes
4448⁽ⁱ⁾	Immediate	33.10 [exec.cmplsig]	Do not forward `fn` in `completion_signatures`	Yes
4449⁽ⁱ⁾	Immediate	21.4.16 [meta.reflection.define.aggregate]	`define_aggregate` members must be public	Yes
4450⁽ⁱ⁾	Immediate	32.5.7.3 [atomics.ref.int]	`std::atomic_ref<T>::store_key` should be disabled for const `T`	Yes
4451⁽ⁱ⁾	Immediate	20.3.2.2.7 [util.smartptr.shared.create]	`make_shared` should not refer to a type `U[N]` for runtime N	Yes
4452⁽ⁱ⁾	Immediate	26.11.1 [specialized.algorithms.general]	Make deref-move constexpr	Yes
4455⁽ⁱ⁾	Immediate	33.9.2 [exec.snd.expos]	Add missing constraint to `basic-sender::get_completion_signatures` definition	Yes
4456⁽ⁱ⁾	Immediate	33.9.2 [exec.snd.expos]	Decay `Data` and `Child` in `make-sender`	Yes
4459⁽ⁱ⁾	Immediate	33.9.2 [exec.snd.expos]	Protect `get_completion_signatures` fold expression from overloaded commas	Yes
4461⁽ⁱ⁾	Immediate	33.9.12.17 [exec.stop.when]	`stop-when` needs to evaluate unstoppable tokens	Yes
4462⁽ⁱ⁾	Immediate	26.2 [algorithms.requirements]	Algorithm requirements don't describe semantics of `s - i` well	Yes
4463⁽ⁱ⁾	Immediate	26.3.2 [algorithms.parallel.user]	Change wording to 'model' from 'subsumes' in [algorithms.parallel.user]	Yes
4464⁽ⁱ⁾	Immediate	26.8.6 [alg.merge]	§[alg.merge] Wording tweaks	Yes
4465⁽ⁱ⁾	Immediate	26.8.5 [alg.partitions]	§[alg.partitions] Clarify Returns: element	Yes