Issue 4429 - WG21 LWG Issues
Title
meta::alignment_of should exclude data member description of bit-field
Status
wp
Section
[meta.reflection.layout]
Submitter
Tomasz Kamiński

Created on 2025-10-24.00:00:00 last changed 1 month ago

Messages

msg15684 (view)
Date: 2025-11-11.10:48:55

Proposed resolution:

This wording is relative to N5014.

  1. Modify [meta.reflection.layout] as indicated:

    consteval size_t alignment_of(info r);

    -7- Returns: […]

    -8- Throws: `meta::exception` unless all of the following conditions are met:

    • (8.1) — `dealias(r)` is a reflection of a type, object, variable of non-reference type, non-static data member that is not a bit-field, direct base class relationship, or data member description (T,N,A,W,NUA) ([class.mem.general]) where W is ⊥..
    • (8.2) — If `dealias(r)` represents a type, then `is_complete_type(r)` is true.

msg15455 (view)
Date: 2025-11-11.10:48:55

[ Kona 2025-11-08; Status changed: Immediate → WP. ]
msg15421 (view)
Date: 2025-11-04.00:43:35

[ Kona 2025-11-03; approved by LWG. Status changed: New → Immediate. ]
msg15420 (view)
Date: 2025-10-27.16:49:03
Addresses US 109-170

[meta.reflection.layout] p#8 This should similarly disallow data member descriptions of bit-fields.

History
Date User Action Args
2025-11-11 10:48:55adminsetmessages: + msg15684
2025-11-11 10:48:55adminsetstatus: immediate -> wp
2025-11-04 00:43:35adminsetstatus: new -> immediate
2025-10-27 09:58:11adminsetmessages: + msg15455
2025-10-24 20:38:54adminsetmessages: + msg15421
2025-10-24 00:00:00admincreate