Cargo Features

fixed-buffer has no features set by default.

[dependencies]
fixed-buffer = { version = "0.5.0", features = ["async-std-feature", "smol-feature", "tokio"] }
async-std-feature = futures-io
smol-feature = futures-io

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-io async-std-feature? smol-feature?
tokio implicit feature

Enables tokio

tokio:

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