{"ast_node_type":"impl","tokens":[{"end":95,"kind":"keyword","start":0,"text":"//"}]}
        // Disambiguate `impl !Trait for Type { ... }` and `impl ! { ... }` for the never type.
    fn parse_polarity(&mut self) -> ast::ImplPolarity {
        if self.check(exp!(Bang)) && self.look_ahead(1, |t| t.can_begin_type()) {