/**
 * @packageDocumentation
 * @module Number
 */
import { OperatorFunction, Subscribable } from 'rxjs';
/**
 * Returns an Observable that emits a number from a source string using Number.parseInt.
 *
 * @category Parse
 *
 * @param radix The number base to convert from. Default is base `10`
 *
 * @example Return only parsed integer values using base `10`
 * ```ts
 * const input = ['RxJS', '-2.3', '0', '1', '2', '3.14', 'Infinity'];
 * from(input).pipe(parseInt()).subscribe();
 * ```
 * Output: `-2, 0, 1, 2, 3`
 *
 * @example Return parsed integer values using base `16`
 * ```ts
 * const input = ['1', 'ff', '40'];
 * from(input).pipe(parseInt(16)).subscribe();
 * ```
 * Output: `1, 255, 64`
 *
 * @returns Observable that emits a number from source parsed string, optionally returns NaN values
 */
export declare function parseInt(radix?: Subscribable<number> | number): OperatorFunction<string, number>;