/**
 * The text of a value. Objects have their keys in order. Values plain JSON loses are written
 * as one-key objects: `{"$set": [...]}`, `{"$map": [[k, v], ...]}` (both sorted, and sorted
 * again when read back from a renamed key, where the names they hold may have changed places),
 * `{"$number": "NaN"}`, `{"$undefined": true}`, `{"$bigint": "12"}`, `{"$date": "..."}`.
 */
export declare function sortedJson(value: unknown): string;
/**
 * Where a value holds something that is not plain data, and what: `"state.handler: a
 * function"`. Undefined when it is all plain data. Such a value cannot be told apart from
 * another or copied faithfully, so the engine refuses it in states and payloads.
 */
export declare function unstorable(value: unknown, path: string): string | undefined;