/**
 * Represents a class that can be used to create a singleton instance of a class that is created asynchronously.
 */
export default class AsyncSingleton<T, R> {
    private readonly factory;
    private readonly checker;
    private queue;
    private instantiating;
    private value?;
    /**
     * Creates a new instance of the AsyncSingleton class.
     * @param factory The factory function that creates the instance.
     * @param checker The function that checks if the instance is valid.
     */
    constructor(factory: (r: R) => Promise<T>, checker?: (value: T) => Promise<boolean>);
    /**
     * Gets the instance of the class.
     * @param r The configuration object for creating the instance.
     */
    instance(r: R): Promise<T>;
    /**
     * Gets the current value, may be undefined or invalid.
     */
    getValue(): T | undefined;
    /**
     * Clears the current value and rejects all pending promises.
     */
    clear(): void;
    private initHere;
    private awaitOtherInit;
}