import { AsyncPredicate, Predicate } from '@naturalcycles/js-lib';
import { TransformOptions, TransformTyped } from '../stream.model';
import { TransformMapOptions } from './transformMap';
/**
 * Just a convenience wrapper around `transformMap` that has built-in predicate filtering support.
 */
export declare function transformFilter<IN = any>(predicate: AsyncPredicate<IN>, opt?: TransformMapOptions): TransformTyped<IN, IN>;
/**
 * Sync version of `transformFilter`
 */
export declare function transformFilterSync<IN = any>(predicate: Predicate<IN>, opt?: TransformOptions): TransformTyped<IN, IN>;