syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"#[derive(Copy,"}]}
source_snippet: #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
context_before: /// know what set of types a given type variable can be unified with.
context_after: #[derive(TypeVisitable_Generic, TypeFoldable_Generic)]