Cargo Features

unstructured = { version = "0.5.1", default-features = false, features = ["selector"] }
default = selector

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

selector default = pest, pest_derive

Features from optional dependencies

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

pest selector

With default features

pest_derive selector

With default (std)