/**
 * Transports a promise which can be resolved or rejected using the given functions.
 * Created by {@link createManualPromise}.
 */
interface ManualPromise<T> {
    /**
     * The promise which will resolve.
     */
    promise: Promise<T>;
    /**
     * Call this function to full fill the promise.
     * @param val the result
     */
    resolve: (val: T) => void;
    /**
     * Rejects the promise.
     * @param e an error
     */
    reject: (e: unknown) => void;
}
/**
 * @returns a ManualPromise which helps to separate a promise from the resolve/reject methods.
 * @example
 *  ```ts
 *  import { createManualPromise } from "apprt-core/promise-utils";
 *
 *  const manualPromise = createManualPromise();
 *
 *  // the created promise
 *  const promise = manualPromise.promise;
 *
 *  // can be resolved by
 *  manualPromise.resolve("value");
 *
 *  // or rejected by
 *  manualPromise.reject(new Error("error"));
 *
 *  // destructuring is allowed
 *  const {promise, resolve, reject} = createManualPromise();
 *  ```
 */
declare function createManualPromise<T>(): ManualPromise<T>;
/**
 * Helper to lazy update a promise and an associated value.
 *
 * @example
 *  ```ts
 *  import { LazyValue } from "apprt-core/promise-utils";
 *
 *  const lazy = new LazyValue();
 *
 *  // code which needs the value, has to use:
 *  const theValue = await lazy.promise;
 *
 *  // code which like to update the value uses:
 *  lazy.value = "newValue";
 *
 *  // the value can updated several times.
 *  // with every update the promise is replaced
 *
 *  // this resets the value to not fulfilled
 *  // the promise will then block again.
 *  lazy.value = undefined;
 *
 *  // NOTE: currently the promise can not be switched into an error state.
 *  ```
 */
declare class LazyValue<T> {
    #private;
    constructor(val?: T);
    /**
     * The promise which will resolve.
     */
    get promise(): Promise<T>;
    set value(val: T | undefined);
    get value(): T | undefined;
}

export { LazyValue, createManualPromise };
export type { ManualPromise };