import { ValidationErrors, AbstractControl, AsyncValidator } from '@angular/forms';
import { Observable } from 'rxjs';
import * as i0 from "@angular/core";
export declare class AsyncValidationDirective implements AsyncValidator {
    async: any;
    validate(control: AbstractControl): Promise<ValidationErrors | null> | Observable<ValidationErrors | null>;
    static ɵfac: i0.ɵɵFactoryDeclaration<AsyncValidationDirective, never>;
    static ɵdir: i0.ɵɵDirectiveDeclaration<AsyncValidationDirective, "[ngModel],[formControlName],[formControl]", never, { "async": "async"; }, {}, never, never, false>;
}