Cargo Features

[dependencies]
incr = { version = "0.2.1", default-features = false, features = ["nightly", "fnv"] }
default = nightly

The nightly feature is set by default whenever incr is added without default-features = false somewhere in the dependency tree.

nightly default

Features from optional dependencies

fnv implicit feature

Enables fnv

fnv:

Fowler–Noll–Vo hash function