Cargo Features

[dependencies]
macos-tun-tap = { version = "0.1.2", default-features = false, features = ["tokio"] }
default = tokio

The tokio feature is set by default whenever macos-tun-tap is added without default-features = false somewhere in the dependency tree.

tokio default = futures, libc, mio, tokio-core

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.

futures tokio

Enables futures ~0.1

libc tokio
mio tokio

Enables mio ~0.6

tokio-core tokio