syntax_data: {"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"#[cfg_attr(feature"}]}
source_snippet: #[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
context_before: #[derive(Clone, Copy, Hash, PartialEq, Eq, Debug)]
context_after: pub enum Certainty {