Cargo Features

enr = { version = "0.10.0", default-features = false, features = ["ed25519", "rust-secp256k1", "k256", "serde"] }
default = k256, serde

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

ed25519 = ed25519-dalek
rust-secp256k1 = secp256k1

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features.

k256 default
serde default
ed25519-dalek ed25519?
secp256k1 rust-secp256k1?

Enables secp256k1 ^0.27