{"ast_node_type":"function","tokens":[{"end":83,"kind":"keyword","start":0,"text":"fn"}]}
    fn ban_mut_general_pat(&self, lo: Span, pat: &Pat, changed_any_binding: bool) {
    /// Error on `mut $pat` where `$pat` is not an ident.
        self.dcx().emit_err(if changed_any_binding {