Cargo Features

[dependencies]
fastvarint = { version = "0.21.0", default-features = false, features = ["serde", "nonmax"] }
default = nonmax, serde

These default features are set whenever fastvarint is added without default-features = false somewhere in the dependency tree.

serde default

Enables serde, serde of nonmax

nonmax default serde

Enables nonmax

fastvarint has 3 features without comments.