Cargo Features

SyncWrapper has no features set by default.

sync_wrapper = { version = "1.0.1", features = ["futures"] }
futures = futures-core

Affects sync_wrapper::SyncStream

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-core futures?