Cargo Features

num-bigint = { version = "0.4.4", default-features = false, features = ["std", "quickcheck", "rand", "serde", "arbitrary"] }
default = std

The std feature is set by default whenever num-bigint is added without default-features = false somewhere in the dependency tree.

std default

Enables std of num-integer and num-traits

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features.

quickcheck implicit feature
rand implicit feature
serde implicit feature
arbitrary implicit feature