Cargo Features

[dependencies]
rustfmt-nightly = { version = "1.4.21", default-features = false, features = ["cargo-fmt", "rustfmt-format-diff", "generic-simd"] }
default = cargo-fmt, rustfmt-format-diff

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

cargo-fmt default
rustfmt-format-diff default
generic-simd

Enables generic-simd of bytecount

rustfmt-nightly has 4 features without comments.