{"ast_node_type":"struct","tokens":[{"end":94,"kind":"keyword","start":0,"text":"//"}]}
                // `struct S<'a, 'b, T>`, match `S::<$0>` to `T` and `S::<'a, $0, _>` to `'b`.
                // its parameter unless a lifetime argument is provided explicitly. That is, for
                // FIXME: This operates on the syntax tree and will produce incorrect results when