Cargo Features

zeroize = { version = "1.7.0", default-features = false, features = ["std", "alloc", "aarch64", "derive", "serde"] }
default = alloc

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

std = alloc
alloc default std?
derive = zeroize_derive

Features from optional dependencies

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

serde implicit feature
zeroize_derive derive?