Cargo Features

Walrus has no features set by default.

walrus = { version = "0.21.1", features = ["parallel"] }
parallel = rayon

Enables rayon of id-arena

Affects tombstone_arena::ParIterMut

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

rayon parallel?