Wow, thanks for the extensive research!

- Victor

On Sat, Oct 29, 2022 at 8:53 AM Corentin Jabot <> wrote:

On Sat, Oct 29, 2022, 17:19 Victor Zverovich via SG16 <> wrote:
As discussed in the thread about LWG3780, while the direction seems promising I don't think we should accept the resolution without a more detailed analysis of the impact of the proposed extensive changes.


On Wed, Oct 26, 2022 at 8:55 AM Tom Honermann via SG16 <> wrote:
Please review the following. If you agree with the proposed change and have no further information to add, then there is no need to respond. If you disagree with the proposed change, have corrections or new information to offer, or have comments on the candidate polls, then please reply by Monday, October 31st.

FR [format.string.std] codepoints with width 2

GitHub nbballot issue #409.
LWG issue 3780.
P2675R0: LWG 3780: The Paper (format's width estimation is too approximate and not forward compatible).


The range of codepoints to be considered of width 2 is not compatible with recent and future unicode versions.

Proposed change:

Please adopt LWG3780 for C++23, backported to C++20

SG16 chair notes:

Thank you to Corentin for filing LWG issue 3780 and for authoring P2675 in response to requests for a more thorough analysis of the consequences of the proposal.

Candidate polls:

  • [FR-XX]: SG16 recommends resolving the comment by adopting P2675R0.
  • [FR-XX]: SG16 recommends rejecting the comment but encourages consideration of P2675R0 for a future standard.
  • [FR-XX]: SG16 recommends rejecting the comment as not a defect.


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