Cargo Features

ray-rust has no features set by default.

[dependencies]
ray-rust = { version = "0.1.5", features = ["with_tokio"] }
with_tokio = tokio

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.

tokio with_tokio?