/**
 * Forcefully asserts the type of the last output to be `T` and returns that original value.
 * @group Other helpers
 * @example
 * using(unknownValue).pipe(
 *     assertType<number[]>(),
 *     reduce((acc, x) => acc + x)
 * );
 */
export declare const assertType: <T>() => (input: unknown) => T;