import type { AnyToVoidFnSignature } from '../misc/functions';
/**
 * Task placeholder with a single place for executing deferred task.
 * Only one task can be planed per DelayedTask instance.
 * @see put DelayedTask.put behavior description.
 */
export declare class DelayedTask {
    protected _fn: AnyToVoidFnSignature | null;
    protected _timeout: number | null;
    /** Execute deferred task immediately */
    protected run: () => void;
    /** @returns Function of currently deferred (planned) task */
    get fn(): AnyToVoidFnSignature | null;
    /**
     * Cancel deferred task and planning passed
     * @param task - task function
     * @param delay - time to delay task execution
     *  - pass negative or false to execute task immediately
     *  - pass 0 to plan task to the macrotask
     *  - pass positive number x to delay task on x ms.
     * */
    put(task: AnyToVoidFnSignature, delay?: number | string | boolean): AnyToVoidFnSignature | null;
    /** Cancel deferred (planned) task */
    cancel(): AnyToVoidFnSignature | null;
}