Cargo Features

[dependencies]
whirlpool = { version = "0.11.0-pre.4", default-features = false, features = ["std", "zeroize"] }
default = std

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

std default

Enables std of digest

zeroize

Enables zeroize of digest

Whirlpool has 3 features without comments.