{"ast_node_type":"impl","tokens":[{"end":70,"kind":"keyword","start":0,"text":"///"}]}
    /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
    (unstable, try_blocks, "1.29.0", Some(31436)),
    (unstable, type_alias_impl_trait, "1.38.0", Some(63063)),