Cargo Features

[dependencies]
tfc = { version = "0.7.0", default-features = false, features = ["check-x11", "x11", "ascii-fallback", "tokio"] }
default = check-x11

The check-x11 feature is set by default whenever tfc is added without default-features = false somewhere in the dependency tree.

check-x11 default
x11
ascii-fallback

Features from optional dependencies

tokio implicit feature

Enables tokio

tokio:

An event-driven, non-blocking I/O platform for writing asynchronous I/O backed applications