Cargo Features

rosu has no features set by default.

[dependencies]
rosu = { version = "0.6.0", features = ["serialize", "metrics"] }
serialize = serde_repr
metrics = prometheus

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.

prometheus metrics?
serde_repr serialize?