› N5034 WG21 Agenda 23-28 March 2026, Croydon, UK
Nina Ranns
N. Ranns
2026-01
Intent
Informational
Abstract
| Doc. No.: | N5022 | | --- | --- | | Date: | 2025-11-01 | | Reply to: | [Nina Dinka Ranns](mailto:dinka.ranns@gmail.com) |
› P1000R7 C++ IS Schedule (proposed)
Herb Sutter
H. Sutter
2026-01
› P2953R3 Forbid defaulting operator=(X&&) &&
Matthew Taylor
M. Taylor
,
Arthur O'Dwyer
A. O'Dwyer
2026-01
Intent
Proposal
Abstract
Currently, [[dcl.fct.def.default]/2.5](https://eel.is/c++draft/dcl.fct.def.default#2.5) permits an explicitly defaulted special member function to differ from the implicit one by adding *ref-qualifiers*, but not *cv-qualifiers*.
› P3039R1 Automatically Generate `operator->`
Andre Kostur
A. Kostur
,
David Stone
D. Stone
2026-01
› P3373R2 Of Operation States and Their Lifetimes
Robert Leahy
R. Leahy
2026-01
Intent
Proposal
Abstract
In broad terms a regular (i.e. synchronous) function call has access to two forms of storage throughout its lifetime (note that the “lifetime” of a regular function call is the time between the call thereto and the return therefrom):
› P3795R1 Miscellaneous Reflection Cleanup
Barry Revzin
B. Revzin
2026-01
Intent
Proposal
Abstract
At the Sofia meeting, [[P2996R13] (Reflection for C++26)](https://wg21.link/p2996r13), [[P3394R4] (Annotations for Reflection)](https://wg21.link/p3394r4), [[P3293R3] (Splicing a base class subobject)](https://wg21.link/p3293r3), [[P3491R3] (`define_static_{string,object,array}`)](https://wg21.link/p349143), [[P3096R12] (Function Parameter Reflection in Reflection for C++26)](https://wg21.link/p30
› P3826R3 Fix Sender Algorithm Customization
Eric Niebler
E. Niebler
2026-01
› P3865R1 Class template argument deduction (CTAD) for type template template parameters
Christof Meerwald
C. Meerwald
2026-01
Intent
Proposal
Abstract
[CWG 3003](https://cplusplus.github.io/CWG/issues/3003.html) "Naming a deducible template for class template argument deduction" has been raised to clarify that with the current core language wording, class template argument deduction does not work for type template template parameters.
› P3873R0 2025-10 Library Evolution Poll Outcomes
Inbal Levi
I. Levi
,
Fabio Fracassi
F. Fracassi
,
Andreas Weis
A. Weis
,
Nevin Liber
N. Liber
,
Billy Baker
B. Baker
,
Corentin Jabot
C. Jabot
2026-01
Intent
Proposal
Abstract
In 2025-10, the C++ Library Evolution group conducted a series of electronic decision polls [[P3872R0]](https://wg21.link/P3872r0). This paper provides the results of those polls and summarizes the results.
› P3911R2 RO 2-056 6.11.2 [basic.contract.eval] Make Contracts Reliably Non-Ignorable
Darius Neațu
D. Neațu
,
Andrei Alexandrescu
A. Alexandrescu
,
Lucian Radu Teodorescu
L. Teodorescu
,
Radu Nichita
R. Nichita
,
Herb Sutter
H. Sutter
2026-01
Intent
Proposal
Abstract
Building on motivation from EWG Kona 2025, this paper proposes a minimal pure extension to the C++26 Contracts facility. This extension addresses the Romanian National Body's (NB) concern by enabling the writing of an individual contract assertion that guarantees the program execution will not continue past the contract assertion if it is violated, regardless of the semantics of other contract ass
› P3927R0 task_scheduler Support for Parallel Bulk Execution
Eric Niebler
E. Niebler
2026-01
› P3941R1 Scheduler Affinity
Dietmar Kühl
D. Kühl
2026-01
Intent
Proposal
Abstract
There are a few NB comments raised about the way `affine_on` works:
› P3950R0 return_value & return_void Are Not Mutually Exclusive
Robert Leahy
R. Leahy
2026-01
Intent
Proposal
Abstract
The standard specifies the effect of `co_return` statements in terms of equivalent statements within the context of a *replacement body* (§9.6.4 [dcl.fct.def.coroutine]). Like a regular `return` statement `co_return` statements have two distinct forms: Those that return `void` and those that return some value. These are specified as follows (§8.8.5 [stmt.return.coroutine]):
› P3951R0 String Interpolation Objects
Barry Revzin
B. Revzin
2026-01
Intent
Proposal
Abstract
The `std::format` approach to formatting offers many significant benefits over the prior `<iostream>`s approach that need not be revisited here. However, `<iostream>` does still have one significant advantage: ordering. It is easy to see at a glance with a long `std::cout` statement which pieces are to be formatted in which order. With `std::format`, as the amount of replacement fields increases,
› P3952R0 is_pointer_in_range
Herb Sutter
H. Sutter
,
Glen Joseph Fernandes
G. Fernandes
2026-01
Intent
Proposal
Abstract
WG21 is often asked for a way to reliably answer the question, “does this raw pointer point inside this buffer?” See [Core 2025] for some use cases. Such an `is_pointer_in_range` function is appropriate to standardize because:
› P3953R0 Rename std::runtime_format
Victor Zverovich
V. Zverovich
2026-01
Intent
Proposal
Abstract
[P2918] introduced `std::runtime_format` to allow opting out of compile-time format string checks in `std::format`. Subsequently, [P3391] made `std::format` usable in constant evaluation. As a result, `std::runtime_format` can now be evaluated at compile time, making its name misleading. This paper proposes renaming `std::runtime_format` to `std::dynamic_format` to better reflect its semantics and
› P3955R0 It's Scopes All the Way Down
Robert Leahy
R. Leahy
2026-01
Intent
Proposal
Abstract
The fundamental scope algorithm is `within`. It establishes a scope by running an enter scope sender. Thereafter it allows a child operation to run (in that scope since the exit scope sender has not yet run), and then before completing the overall operation runs the exit scope sender yielded by the enter scope sender.
› P3959R0 Let layout_stride::mapping with zero extent(s) accept zero strides
Mark Hoemmen
M. Hoemmen
,
Jacob Faibussowitsch
J. Faibussowitsch
,
Christian Trott
C. Trott
2026-01
Intent
Proposal
Abstract
We propose to change `layout_stride::mapping`’s constructors to permit strides to be zero if one or more extents are zero. For example, for extents (3, 5, 0, 11), this change would permit any nonnegative strides. Currently, users would need to set the stride(s) corresponding to zero extents to an arbitrary positive value, such as 1. That would make the strides (1, 3, 1, 105) in this example.
› P3960R0 Define copy-constructibility-from-bytes
Mark Hoemmen
M. Hoemmen
,
Ruslan Arutyunyan
R. Arutyunyan
2026-01
Intent
Proposal
Abstract
Given an object `src` of trivially-copyable type `T`, we can copy the object’s value representation to an array of bytes, and implicitly create a new `T` object (e.g., with `start_lifetime_as`) in the array of bytes. The result will hold the same value as `src`.
› P3961R0 Less double indirection in function_ref (RU-220)
Zhihao Yuan
Z. Yuan
2026-01
Intent
Proposal
Abstract
RU-220 calls for allowing skipping indirections when constructing `function_ref` to improve codegen. The proposed change in LWG 4264<sup>[1]</sup> is not strictly an optimization because certain behaviors with and without the change are visible, therefore, need to be made unspecified. This paper (P3961) suggests that, in addition to the change, a subset of the "optimized" cases should be mandated.
› P3962R0 Implementation reality of WG21 standardization
Nina Ranns
N. Ranns
2026-01
Intent
Proposal
Abstract
As a committee, we have a shared goal: maintaining a standard that delivers real value to users while remaining implementable, performant, and portable. Our intention is to start a series of conversations about constructive steps we can take as a group toward narrowing the gap between standardization and implementation. We would like to see discussion about improving early communication, making co
› P3963R0 Assignable lambdas with capture
Ruslan Arutyunyan
R. Arutyunyan
2026-01
Intent
Proposal
Abstract
This paper proposes making lambdas with captures copy assignable and move assignable when all captured entities are themselves assignable.
› P3965R0 2026-01 Library Evolution Polls
Inbal Levi
I. Levi
,
Fabio Fracassi
F. Fracassi
,
Andreas Weis
A. Weis
,
Billy Baker
B. Baker
,
Nevin Liber
N. Liber
,
Corentin Jabot
C. Jabot
2026-01
Intent
Proposal
Abstract
This paper contains the decision polls that the C++ Library Evolution group will take in January 2026.
› P3967R0 Dual compiles of functions with contracts
Bengt Gustafsson
B. Gustafsson
2026-01
› P3968R0 A Framework For Contracts
Bengt Gustafsson
B. Gustafsson
2026-01
