Cargo Features

allocator-api2 = { version = "0.2.16", default-features = false, features = ["std", "alloc", "nightly", "serde"] }
default = std

The std feature is set by default whenever allocator-api2 is added without default-features = false somewhere in the dependency tree.

std default = alloc
alloc std

Affects stable::boxed, stable::vec


Features from optional dependencies

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

serde implicit feature

With default (std)

Affects vec::cautious, vec::InPlaceSeed