Cargo Features

[dependencies]
hlist = { version = "0.1.2", default-features = false, features = ["with_serde"] }
default = with_serde

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

with_serde default = serde, serde_derive

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.

serde with_serde
serde_derive with_serde