Cargo Features

[dependencies]
subatomic = { version = "0.2.1", default-features = false, features = ["u64", "u32", "serde"] }
default = u32, u64

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

u64 default
u32 default

Features from optional dependencies

serde implicit feature

Enables serde

serde:

A generic serialization/deserialization framework