Cargo Features

[dependencies]
mexprp = { version = "0.3.1", default-features = false, features = ["rug"] }
default = rug

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

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.

rug default