Reviewed in LWG on Thursday; paper needs minor edits.

New version D0627r4

This was not adopted for C++20. Removing the "C++20" label.

LWG small group in Prague -- author was sent feedback.

@JeffGarland @brycelelbach @villevoutilainen

Are we able to reach the author? Otherwise, how can we help this paper make progress?

@cor3ntin - The last attempt was after the Prague meeting -- there was no response. I don't know the author so perfectly possible my email went to spam. As a general rule, however, I'm don't have time to babysit authors w.r.t. updating papers. That said if someone knows the author and would like to try again we'd be happy to help with getting the changes done and scheduling the review.

The feedback supplied was from this wiki page:

https://wiki.edg.com/bin/view/Wg21prague/LWGSatAfternoonSmallGroupReviews

@cor3ntin, I should be taking over. I got the source document back in June, but it slipped. Trying again for the next mailing.

@jensmaurer Happy to look at this before the mailing -- that is, ready to schedule as soon as you update. Let me know if there are questions from the wiki notes, but I think they are mostly minor things which you're well familiar with.

LWG reviewed on 2021-09-10 and removed an overload as not supportable by implementations, but approved the paper otherwise for C++23 pending the ok from LEWG.

JM: the paper is in front of the LEWG for the removal of the message overload

@ben-craig it was noted that this facility should likely be part of freestanding.

https://wiki.edg.com/bin/view/Wg21telecons2021/P0627-20210910

Accept P0627r5 to C++23 pending LEWG approval of the updated design?

LEWG reflector discussion started 2021-09-09: http://lists.isocpp.org/lib-ext/2021/09/19890.php

A Library Evolution motion was made on the mailing list to electronic poll removing the message parameter. There was a substantial amount of discussion, but that discussion was largely clarifications about std::unreachable or inquires about how it is implemented, not objections to the removal of the message parameter. As such, Library Evolution will proceed with electronic polling the removal of the message parameter. We'll also need to affirm that std::unreachable belongs in freestanding.

P0627R5 Function to mark unreachable code (Jens Maurer)

This paper was discussed at the Oct 1 2021 SG22 meeting. No polls were taken and SG22 does not need to see this paper again.

P0627R6 Function to mark unreachable code (Jens Maurer)

Per our prior review and vote I'm setting this ready for plenary since LEWG agrees with the suggested changes from our prior review. The R6 change was editorial and doesn't require LWG to re-review.

2021-11 Library Evolution Electronic Poll Outcomes

Send [P0627R6] (Function To Mark Unreachable Code), which was previously approved and has been modified to remove the message parameter, to Library Working Group for C++23, classified as an addition ([P0592R4] bucket 3 item)

Strong consensus in favor

Approved by WG21 plenary 2022-02-07