Cargo Features

virtual-mio has no features set by default.

[dependencies]
virtual-mio = { version = "0.5.0", features = ["sys", "js"] }
sys = mio, socket2
js

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.

mio sys?
socket2 sys?