import { Observable } from 'rxjs';
export declare function observeElementSize(element: Element, config?: {
    options?: ResizeObserverOptions;
}): Observable<DOMRectReadOnly>;
export declare function observeElementSize<T>(element: Element, config?: {
    options?: ResizeObserverOptions;
    extract: (entries: ResizeObserverEntry[]) => T;
}): Observable<T>;