Cargo Features

[dependencies]
num-to-words = { version = "0.1.1", default-features = false, features = ["en_us", "uk_ua"] }
default = en_us

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

en_us default
uk_ua

num-to-words has 3 features without comments.