Cargo Features

wit-bindgen = { version = "0.16.0", default-features = false, features = ["macros", "realloc"] }
default = macros, realloc

These default features are set whenever wit-bindgen is added without default-features = false somewhere in the dependency tree.

macros default = wit-bindgen-rust-macro
realloc default

Features from optional dependencies

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

wit-bindgen-rust-macro macros