import { type ExcludeNoUpdate } from './no-update.js';
/**
 * The possible types for an async observable's value, each representing a different potential phase
 * in the promise lifecycle.
 *
 * @category AsyncValue
 */
export type AsyncValue<Value> = Error | Promise<ExcludeNoUpdate<Value>> | ExcludeNoUpdate<Value>;
/**
 * Maps an async value to a new async value.
 *
 * @category AsyncValue
 */
export declare function mapAsyncValue<const OriginalValue, const MappedValue>(asyncValue: AsyncValue<OriginalValue>, mapper: (value: NoInfer<OriginalValue>) => MappedValue): AsyncValue<MappedValue>;
/**
 * If the given async value is resolved, return `true`. Otherwise, `false`. Type guards the input.
 *
 * @category AsyncValue
 */
export declare function isAsyncValueResolved<const T>(asyncValue: AsyncValue<T>): asyncValue is ExcludeNoUpdate<T>;
/**
 * If the given async value is resolved, its value is returned. Otherwise, `undefined` is returned.
 *
 * @category AsyncValue
 */
export declare function resolvedAsyncValue<const T>(asyncValue: AsyncValue<T>): T | undefined;