import { AsyncOperator } from '../../AsyncSeq';
/**
 * Returns the sequence to which the specified value is added.
 *
 * ```typescript
 * const result = await fromAsAsync([1, 2]).pipe(
 *   concatValueAsync(3)
 * ).toArrayAsync();
 * //result: [1,2,3]
 * ```
 *
 * @param target Element you want to add to the sequence.
 * @returns Operator function.
 * @typeParam T Source element type.
 * @category Async Operators
 */
export declare const concatValueAsync: <T>(target: T) => AsyncOperator<T, T>;