import { Option } from './option';
/**
 * Return a `None` if `option` does not contain a value,
 * otherwise call `predicate` and return:
 *   * a `None` if `predicate` returns `false`
 *   * a `Some` if `predicate` returns `true`
 * @param option Option to match against
 * @param predicate Whether should `filter` return a `Some` when `option` contains a value
 * @returns An `Option`
 */
export declare const filter: <Value = never>(option: Option<Value>, predicate: (value: Value) => boolean) => Option<Value>;
export default filter;