/**
 * Resolve method signature.
 *
 * @public
 */
type Resolver<R = void> = (value: R) => void;
/**
 * Reject method signature.
 *
 * @public
 */
type Rejection = (reason?: string | Error | unknown) => void;
/**
 * Abstract deferred promise.
 *
 * @public
 */
interface Deferral<R = void> {
    /** Abort signal, if provided at construction. */
    readonly signal?: AbortSignal;
    /** Root promise instance. */
    promise(): Promise<R>;
    /** Internal resolve function. */
    resolve(value: R): void;
    /** Reject root promise. */
    reject(reason?: string | Error | unknown): void;
    /** Alias to await root promise. */
    untilResolved(): Promise<R>;
    /** Test if deferral has already been resolved or rejected. */
    isComplete(): boolean;
}

/**
 * Deferred Promise
 *
 * @remarks
 * Allows extraction of a root promise's resolve/reject methods to use
 * outside the promise context.
 *
 * @public
 */
declare class DeferredPromise<R = void> implements Deferral<R> {
    #private;
    /**
     * Constructor.
     *
     * @param signal - Optional abort signal to reject root promise.
     *
     * @public
     */
    constructor(signal?: AbortSignal);
    /**
     * Exposes any provided abort signal.
     *
     * @public
     */
    get signal(): AbortSignal | undefined;
    /**
     * Returns root promise.
     *
     * @public
     */
    promise(): Promise<R>;
    /**
     * Resolves root promise.
     *
     * @param result - Any typed result.
     *
     * @public
     */
    resolve(result: R): void;
    /**
     * Rejects root promise.
     *
     * @param reason - Any string message or error instance.
     *
     * @public
     */
    reject(reason: string | Error | unknown): void;
    /**
     * Alias to await root promise.
     *
     * @public
     */
    untilResolved(): Promise<R>;
    /**
     * Checks root promise state.
     *
     * @public
     */
    isComplete(): boolean;
}

/**
 * Provide a Deferred Promise instance.
 *
 * @param signal - Optional abort signal to reject root promise.
 *
 * @public
 */
declare const defer: <R = void>(signal?: AbortSignal) => Deferral<R>;

export { Deferral, DeferredPromise, Rejection, Resolver, defer };