import { MonoTypeOperatorFunction } from 'rxjs';
import { PredicateFunction } from '../types';
export interface ValidateParams<T> {
    validation: PredicateFunction<T>;
    error?: string;
}
/**
 * Validates the source emitted value, throws an error when validation
 * doesn't pass
 * @param params -
 * - validation: predicate function to test emitted value
 * - error: message in case of error
 * @returns an operator function that validates emitted values
 */
export declare function validate<T>({ validation, error, }: ValidateParams<T>): MonoTypeOperatorFunction<T>;