P3372 R3 constexpr containers and adapters

[wg21bot]

P3372R0 constexpr containers and adapters (Hana Dusíková)

[wg21bot]

P3372R1 constexpr containers and adapters (Hana Dusíková)

[inbal2l]

2024-10-08 Library Evolution Telecon

P3372R0: constexpr containers and adaptors

2024-10-08 Library Evolution Telecon Minutes

Champion: Hana Dusikova
Chair: Fabio Fracassi
Minute Taker: Alisdair Meredith

Summary

POLL: We approve of the general design of P3372R0 (modulo the changes on node_handle)

SF	F	N	A	SA
10	2	2	0	0

Attendance: 16

# of Authors: 1

Author's Position: SF

Outcome: Strong consensus in favour

Some implementer concerns over (non ABI breaking) implementability of maps for some toolchains, came up at the end of the discussion.
It might be useful to move these parts to a separate paper, to speed along the uncontended parts (the major part of this paper), while still allowing for the concerns to be resolved in their own time

Next Steps

Two options:
- Add wording that map node_handle::key is not usable in constexpr. (i.e. remove constexpr from node_handle::key)
- Make all functions that use node_handles not constexpr
Update: concernes were addressed in R2 (https://isocpp.org/files/papers/P3372R2.html#history)

[wg21bot]

P3372R2 constexpr containers and adapters (Hana Dusíková)

[inbal2l]

2025-01-28 Library Evolution Telecon

P3372R2 constexpr containers and adapters

2025-01-28 Library Evolution Telecon Minutes

Champion: Hana Dusíková
Chair: Inbal Levi
Minute Taker: Andreas Weis

Summary

POLL: Forward P3372R2 to LWG for C++26.

SF	F	N	A	SA
12	8	2	0	0

Attendance: 27
Author's Position: SF
Outcome: Strong consensus in favor

Paper forwarding checklist:

• Why should this facility go into the standard library? Improvement
• Examples? Yes
• Field experience?
  • Implementation experience? Yes
  • Usage experience? Some
  • Deployment experience? No
• Performance considerations? Discussed
• Constexpr? YES 🙂
• Discussion of prior art? Some
• Changes Library Evolution previously requested? Yes (see R1->R2)
• Support for "std::format", "hash", and allocators (if required)? Discussed
• Wording? Yes
• Feature test macro? Yes
• Freestanding? N/A

Next Steps

P3372R2 was forwarded to LWG for C++26.

[bstamour]

LWG reviewed this Tuesday in Hagenberg:

“Voting for p3372r3 in c++26” (with minor changes checked by Jeff and Bryan)
| F | N | A |
| 11 | 0 | 0 |

[wg21bot]

P3372R3 constexpr containers and adapters (Hana Dusíková)