{"ast_node_type":"variable","tokens":[{"end":65,"kind":"keyword","start":0,"text":"let"}]}
    let $0t = &(0, (1,"1"), Some(2), [3;3], S4 { value: 4 }, &5);
fn foo() -> Option<()> {
    let v: i32 = t.0;           // deref, no parens