import type { Ref } from './types/outputs/Ref.js';
/**
 * Builds a Ref object around fn.
 * Produced object will deduplicate calls to fn, meaning that all "defer" calls made while fn is running won't call fn
 * again and all will return at the same time.
 *
 * @example
 * let value = 1;
 *
 * const ref = deferrable$(() => value);
 * console.log(ref.defer()); // prints 1
 *
 * value = 2;
 * console.log(ref.defer()); // prints 2
 *
 * @param fn function returning deferred value
 *
 * @since 2.0.0
 */
export declare function ref$<D>(fn: (signal: AbortSignal) => D): Ref<D>;