P3691 R0 Reconsider naming of the namespace for "std::simd"

[wg21bot]

P3691R0 Reconsider naming of the namespace for "std::simd" (Matthias Kretz, Abhilash Majumder, Bryce Adelstein Lelbach, Daniel Towner, Ilya Burylov, Mark Hoemmen, Ruslan Arutyunyan)

[inbal2l]

2025-06-16 LEWG Sofia Meeting

P3691R0: Reconsider naming of the namespace for "std::simd"

2025-06-16 Library Evolution Sofia Minutes

Champion: Matthias Kretz
Chair: Fabio Fracassi / Inbal Levi
Minute Taker: Bronek Kozicki

Summary

POLL: We can live with the duplicated namespace::type name simd::simd

SF	F	N	A	SA
8	7	2	5	3

Attendance: 23 (IP) + 6 (R)
Author's Position: SF, A, SA
Outcome: Very weak consensus

POLL: Rename std::datapar::simd to std::simd::simd and std::datapar::simd_mask to std::simd::mask

SF	F	N	A	SA
8	9	3	4	5

Attendance: 24 (IP) + 5 (R)
Author's Position: X
Outcome: Consensus in favour

POLL: Rename std::datapar::simd to std::simd::pack and std::datapar::simd_mask to std::simd::mask

SF	F	N	A	SA
6	8	5	5	2

Attendance: 24 (IP) + 6 (R)
Author's Position:
Outcome: Very weak consensus

POLL: We prefer std::simd::pack over std::simd::simd

SF	F	N	A	SA
9	4	4	5	5

Attendance: 24 (IP) + 6 (R)
Author's Position: A
Outcome: No consensus

POLL: Vote for all the names you like (name with most votes will be chosen):

Name	Votes
std::simd::pack	13
std::simd::simd	11
std::simd::vec	24
std::simd::batch	5

Outcome: std::simd::vec got strongest consensus

POLL: Forward “P3691R0: Reconsider naming of the namespace for “std::simd” with “std::simd::vec” to LWG for C++26.

SF	F	N	A	SA
21	3	1	1	0

Attendance: 25 (IP) + 6 (R)
Author's Position: 3x SF
Outcome: Strong consensus in favor

Next Steps

Forwarded "P3691R0: Reconsider naming of the namespace for “std::simd”" with “std::simd::vec” to LWG for C++26.