- This is more of a question for LWG. The IANA registry is
not versioned, but does contain a last updated time stamp. No
stability guarantees are provided, nor is there an obvious way
to access older revisions of the registry. Is a reference
ok? Or do we need to include the contents in the standard?
The IANA registry had not been updated for many years until
just a month ago when "UTF-7-IMAP" was added.
IANA is already referenced in the bibliography and the chrono sections of the standard in relation to the time zone interface. There’s no versions or stability there either — just a link. Howard can probably clarify, but pretty sure all that was intentional to avoid instability in the c++ spec — that is stay out of the quagmire or ever changing time zone data.
The difference I see is that P1885, as currently drafted, basically pulls in ’the list of encodings' from IANA, where chrono completely dodges doing anything of the sort. Not sure there’s a way to achieve the goals of P1885 without that, but it’s clearly more dependent than chrono.