# 0.13.0 - **Breaking change:** adopt the new `Durability` API proposed in [RFC #6] - this replaces and generalizes the existing concepts of constants - **Breaking change:** remove "volatile" queries - instead, create a normal query which invokes the `report_untracked_read` method on the salsa runtime - introduce "slots", an optimization to salsa's internal workings - document `#[salsa::requires]` attribute, which permits private dependencies - Adopt `AtomicU64` for `runtimeId` (#182) - use `ptr::eq` and `ptr::hash` for readability - upgrade parking lot, rand dependencies [RFC #6]: https://github.com/salsa-rs/salsa-rfcs/pull/6