syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                     // an outermost hir::Ty as we descend, matching up
context_before:                     // hypothetically, `visit_primary_bindings` could try to unzip
context_after:                     // idents in pat; but complex w/ unclear UI payoff.