Make once_cell optional to meet reasonable MSRV about ahash HOT 8 OPEN

There's a big range of possibilities between "debian stable" and "latest stable". once_cell is using "about a year old MSRV". This is very comfortable for folks who try to generally keep up to date. That is not enough for various LTSes, which are typically more-than-a-year long.

from ahash.

Yep, its totally a reasonable decision...maintainers get to decide what they want to support. Doesn't mean downstream projects shouldn't/can't decide to switch if they want to support more :). In this case we're switching, and it'd be easiest for us if ahash also switches, otherwise we'll swap ahash for a different hasher in our (nostd) hashtables...hence this issue/question.

from ahash.

I was under the impression that once_cell's MSRV was bumped to 1.56.0, rather than being abandoned entirely?

from ahash.

I don't believe so, no, that's just the current effective MSRV, quoting the linked issue:

We support workflows which target up-to-date, supported versions of Rust compiler, but we also give somewhat generous grace period, as keeping perfectly up-to-date is hard.

We explicitly do not support workflows which depend on using the old compiler. Making sure that the latest once_cell can be compiled with rustc packaged with debian stable is a non-goal.

from ahash.

That is not enough for more-than-a-year LTSes.

Anything below a year is not really worth calling it LTS, is it? After all, the L in LTS stands for "Long", and something like six months is not really long.

Don't get me wrong here: Code maintainers / owners always get to decide what they support and for how long they are willing to support it. But everything below a year does not really deserve to be called LTS, in my opinion.

from ahash.

Thanks, my wording was ambiguous, clarified.

from ahash.

Some features like: #136 do impose version requirements. (For example that feature won't wore before 1.54) I don't know a way to do conditional compilation based on the Rust version number. So removing onceCell may not be the only obstacle.

I am using use once_cell::race::OnceBox which is a very small amount of code. Rather than try to find a way around it, it might be better to break that out into its own crate.

from ahash.

At least for my use-case (no-std hashmaps by directly depending on hashbrown, which disables ahash default-features), I'm not worried about the std feature. Ideally, of course, that too would have a strong MSRV guarantee, but providing a strong MSRV guarantee for some feature subset is still a good step forward.

from ahash.