use Cell;
/// A metrics-only cell backed by [`Cell<u64>`].
///
/// All accesses must be externally synchronized (e.g. by an `RwLock`).
/// This type is **not** safe for unsynchronized concurrent use.
pub ;
// SAFETY:
// All access to MetricsCell is externally synchronized by an RwLock.
// Metrics are observational and do not affect correctness.
unsafe
unsafe