Issue 4620 - WG21 LWG Issues
Title
Clarify whether there is any requirement for "the behavior is unspecified (possibly ill-formed)"
Status
new
Section
[namespace.std]
Submitter
Jiang An

Created on 2026-09-09.00:00:00 last changed 1 week ago

Messages

msg16614 (view)
Date: 2026-09-09.00:00:00

Since C++20/P0551R3, in [namespace.std], we say some constructs (taking address of a non-addressable function etc.) may cause the behavior of a program unspecified and possibly ill-formed. This sounds very similar to "ill-formed, no diagnostic required", but it is unclear whether there are still some imposed requirements so we should not say IFNDR.

Perhaps it is better to either

  • clarify that there are still some requirements imposed for these cases so it is unsuitable to say IFNDR, or

  • rephrase these restrictions to say IFNDR.

History
Date User Action Args
2026-09-09 00:00:00admincreate