{"ast_node_type":"other","tokens":[{"end":51,"kind":"keyword","start":0,"text":"self.look_ahead(start,"}]}
        self.look_ahead(start, |t| t == &token::Lt)
        // (`impl <Type>::AssocTy { ... }`) aren't even allowed by type checker at the moment.
            && (self.look_ahead(start + 1, |t| t == &token::Pound || t == &token::Gt)