syntax_data: {"ast_node_type":"struct","tokens":[{"end":74,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // be a unit struct or unit variant (e.g. `Option::None`).
context_before:                 // The path isn't the name of a constant, so it must actually
context_after:                 let kind = self.lower_variant_or_leaf(res, id, span, ty, vec![]);