intruder_alarm stability

[hawkw]

Right now, core::ptr::NonNull (née ptr::Shared) is the main unstable feature blocking intruder_alarm from building with the stable compiler. As of rust-lang/rust#46952, it's coming to stable Real Soon Now (under its' new name).

The other gated feature that intruder_alarm uses is const_fn, which is pretty easy to hack around (e.g. with a macro) or just with conditional compilation. In light of that, intruder_alarm may soon compile on stable Rust.

Let's try to avoid adding any new feature gates, so that when ptr::NonNull makes it to stable, intruder_alarm will build against stable.

[leshow]

Isn't the custom allocator stuff for nightly only also?

[hawkw]

@leshow

Isn't the custom allocator stuff for nightly only also?

Yeah, that's correct. But if nothing is keeping the intrusive collections crate --- separate from the actual allocator implementations --- from building on stable, why not? I'm sure there are some other use-cases for intrusive collections other than writing allocators...

[hawkw]

(which is my way of saying, "i'd like to ship intruder_alarm to crates.io independently of the allocators)