{"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"self.parse_pat_ident(BindingMode(ByRef::Yes(mutbl),"}]}
            self.parse_pat_ident(BindingMode(ByRef::Yes(mutbl), Mutability::Not), syntax_loc)?
            let mutbl = self.parse_mutability();
        } else if self.eat_keyword(exp!(Box)) {