Cargo Features

[dependencies]
futures-async-runtime-preview = { version = "0.2.3", default-features = false, features = ["std", "nightly"] }
default = std

The std feature is set by default whenever futures-async-runtime-preview is added without default-features = false somewhere in the dependency tree.

std default

Enables std of futures-core-preview and futures-stable-preview

nightly

Enables nightly of futures-core-preview and futures-stable-preview

futures-async-runtime-preview has 3 features without comments.