Cargo Features

gray_matter = { version = "0.2.6", default-features = false, features = ["toml", "yaml"] }
default = toml, yaml

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

Features from optional dependencies

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

toml default

Enables toml ^0.5.9

Affects engine::toml

yaml default

Enables yaml-rust

Affects engine::yaml