{"ast_node_type":"other","tokens":[{"end":118,"kind":"keyword","start":0,"text":"(@pat(vec:$vec:expr,"}]}
    (@pat(vec:$vec:expr, sub_tys:$sub_tys:expr, idx:$idx:expr, ctor:$ctor:expr) { $($fields:tt)* } $($rest:tt)*) => {{
    }};
        let sub_tys = $sub_tys;