Cargo Features

[dependencies]
fixed-num = { version = "0.1.1", default-features = false, features = ["i256_ethnum", "i256_arrow", "mul_opt"] }
default = i256_ethnum, mul_opt

These default features are set whenever fixed-num is added without default-features = false somewhere in the dependency tree.

i256_ethnum default = ethnum
i256_arrow = arrow-buffer
mul_opt default

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.

arrow-buffer i256_arrow?
ethnum i256_ethnum