P4185 R1 Completing the Mathematical Model for C++ Quantities and Units

[wg21bot]

P4185R0 Completing the Mathematical Model for C++ Quantities and Units (Mateusz Pusz)

[mattkretz]

P4185R0: Completing the Mathematical Model for C++ Quantities and Units

2026-06-09/11 SG6 Minutes

Chair: Matthias Kretz

Champion: Mateusz Pusz

Summary

• Seen on Tuesday morning; SG6 needs more time, hopefully on Thursday.
• On Thursday SG6 worked through Section 6 and 8 of the proposal.

Polls

POLL: Encourage implementation (aka more work) on Section 6 "Absolute quantities" in P4185R1. SG6 believes this
approach is likely to increase consensus of P3045R8 "Quantities and units library".

SF	F	N	A	SA
6	1	2	0	1

Outcome: Consensus in favor
SA: I would change my vote if it was more restricted to temperature.

POLL: Encourage a split of Section 8 "Range-validated quantity points" in P4185R1 into its own paper so that we can
forward it to LEWG. SG6 believes this approach is likely to increase consensus of P3045R8 "Quantities and units
library".

SF	F	N	A	SA
3	5	1	1	0

Outcome: Consensus in favor
A: Not sure that it's actually ready. Better to do a bit more exploration.

[wg21bot]

P4185R1 Completing the Mathematical Model for C++ Quantities and Units (Mateusz Pusz)