Cargo Features

HMAC-SHA256 has no features set by default.

hmac-sha256 = { version = "1.1.7", features = ["opt_size", "traits", "traits09", "traits010"] }
traits = traits010, traits09
traits09 traits? = digest09
traits010 traits? = digest010

Affects hmac-sha256::WrappedHash

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.

digest09 traits09?

Enables digest ^0.9.0

digest010 traits010?

Enables digest