The "future_atomic_orderings" feature is broken.

[lachlansneff]

Compiling code that matches against core::sync::atomic::Ordering requires the future_atomic_orderings feature to be enabled. But, when I enable that feature, I get

error[E0635]: unknown feature `future_atomic_orderings`
  --> src/main.rs:33:5
   |
33 |     future_atomic_orderings,
   |     ^^^^^^^^^^^^^^^^^^^^^^^

[varkor]

This is a bug with the feature collector; thanks for reporting!

Not that in this case specifically, it shouldn't be a problem anyway. You can match over all variants of core::sync::atomic::Ordering except for Ordering::__Nonexhaustive. This is specifically hidden so that you don't try to exhaustively match the enum. You should be using a catch-all _ arm instead.

Really, Ordering should be using #[non_exhaustive] instead.

[lachlansneff]

Yeah, that's how I'm sidestepping this bug for now, but actually, the code in libcore does match against the __Nonexhaustive case, which I was largely copying.