import { PipeTransform } from '@angular/core';
import * as i0 from "@angular/core";
export declare class ClassListPipe implements PipeTransform {
    /**
     * Transforms a default class and an optional array of classes into a single string.
      * @param classes Array of additional class names (or string if user provided direct class).
      * @param defaultCls Base class to apply when array is empty or undefined.
     */
    transform(classes: string[] | string | null | undefined, defaultCls: string): string;
    static ɵfac: i0.ɵɵFactoryDeclaration<ClassListPipe, never>;
    static ɵpipe: i0.ɵɵPipeDeclaration<ClassListPipe, "classList", false>;
}