Cargo Features

hmmmm has no features set by default.

[dependencies]
hmmmm = { version = "0.1.2", features = ["derive"] }
derive = hmmmm_derive

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

hmmmm_derive derive?