Cargo Features

RollingDualCrc has no features set by default.

[dependencies]
rolling-dual-crc = { version = "0.1.0", features = ["fast"] }
fast = crc32c, crc64fast

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.

crc32c fast?
crc64fast fast?