FR-015-026 24.7.3 [views.span] Remove `cbegin` / `cend` from spans and views

[wg21bot]

views::as_const, ranges::cbegin, const_iterator are enough ways to produce a constant iterator already.
Adding member functions producing const_iterator does no seem more justified than member functions producing any other view adaptor, and the cases where an iterator is needed should be rare as ranges gets more widely adopted.

Please consider removing span::cbegin/cend, and view_interface::cbegin/cend.

[brycelelbach]

Okay this will be fun. This probably needs a paper.

[brycelelbach]

2022-11-07 10:00 to 11:30 UTC-10 Kona Library Evolution Meeting

FR-015-026: Remove cbegin/cend from spans and views

2022-11-07 10:00 to 11:30 UTC-10 Kona Library Evolution Minutes

Champion: Corentin Jabot (in-person)

Chair: Bryce Adelstein Lelbach & Fabio Fracassi

Minute Taker: Inbal Levi

Start: 2022-11-07 10:10 UTC-10

POLL: Remove span::cbegin/cend and view_interface::cbegin/cend.

Strongly Favor	Weakly Favor	Neutral	Weakly Against	Strongly Against
0	1	1	17	13

Attendance: 25 (in-person) + 20 (remote)

# of Authors: 1

Author Position: WF

Outcome: Strong consensus against.

End: 10:35

Summary

This NB comment proposes removing span::cbegin/cend and view_interface::cbegin/cend. These facilities were part of a carefully constructed compromise on the committee, and Library Evolution feels that removing them would decrease consensus.

Next Steps

Take a Library Evolution electronic poll to reject C++23 NB comment FR-015-026 (Remove cbegin/cend From Spans and Views).