Cargo Features

[dependencies]
exhaust = { version = "0.2.1", default-features = false, features = ["std", "alloc"] }
default = std

The std feature is set by default whenever exhaust is added without default-features = false somewhere in the dependency tree.

std default = alloc
alloc std

Enables itertools

itertools is used for its powerset iterator, which is only available with alloc