syntax_data: {"ast_node_type":"other","tokens":[{"end":20,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// variant `v`.
context_before:     /// Calls `f` with a reference to the name of the enumerator for the given
context_after:     fn variant_name(v: VariantIdx) -> Cow<'static, str> {