P3726 R2 Adjustments to Union Lifetime Rules

[wg21bot]

P3726R0 Adjustments to Union Lifetime Rules (Barry Revzin, Tomasz Kamiński)

[jensmaurer]

EWG should see this first.

[erichkeane]

EWG discussed this in Kona on Wednesday morning along with similar NB comments. The results are below:

DE-087 11.4.5.2 [class.default.ctor] Fix trivial unions - we want to pursue a change for C++26 as proposed in P3726R0

SF	F	N	A	SA
8	14	1	0	0

consensus

US 48-086 11.4.5.2 [class.default.ctor] Fix trivial unions - we want to pursue a change for C++26 as proposed in P3726R0

SF	F	N	A	SA
7	14	1	0	0

consensus

FR-006-088 11.5.1 [class.union.general] Remove trivial unions - we want to pursue a change for C++26

SF	F	N	A	SA
1	3	1	9	9

not consensus

PL-003 11.4.5.2 [class.default.ctor] Revert trivial unions and constexpr inplace_vector - we want to pursue a change for C++26


SF	F	N	A	SA
1	2	1	14	3

not consensus

As consensus was to accept P3726R0, we also polled to forward it to CWG:

P3726R0 Adjustments to Union Lifetime Rules: Forward to CWG for inclusion in C++26


SF	F	N	A	SA
13	9	0	0	0

consensus

[jensmaurer]

CWG 2025-11-05 in Kona: Reviewed; needs updates.

[wg21bot]

P3726R1 Adjustments to Union Lifetime Rules (Barry Revzin, Tomasz Kamiński)