Cargo Features

deser-json has no features set by default.

[dependencies]
deser-json = { version = "0.8.0", features = ["speedups"] }
speedups = itoa, ryu

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.

itoa speedups?
ryu speedups?