interface FieldValueMarker {
    __type__: string;
    [key: string]: any;
}
export declare class FieldValue {
    private readonly marker;
    private constructor();
    static serverTimestamp(): FieldValue;
    static arrayUnion(...elements: any[]): FieldValue;
    static arrayRemove(...elements: any[]): FieldValue;
    static delete(): FieldValue;
    static increment(operand: number): FieldValue;
    toJSON(): FieldValueMarker;
}
export {};