syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// will have type `&T`. The second local is a binding for occurrences of
context_before:     /// first local is a binding for occurrences of `var` in the guard, which
context_after:     /// `var` in the arm body, which will have type `T`.