{"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"///"}]}
    /// Allows `#[marker]` on certain traits allowing overlapping implementations.
    (unstable, macro_metavar_expr_concat, "1.81.0", Some(124225)),
    (unstable, marker_trait_attr, "1.30.0", Some(29864)),