import type { RefObject } from "react";
export interface ElementSize {
    width: number;
    height: number;
}
/**
 * Tracks the width and height of an HTML element in real-time.
 * Uses `ResizeObserver` under the hood.
 *
 * @param ref - The React ref attached to the element you want to measure.
 * @returns Object containing the exact `width` and `height` in pixels.
 *
 * @example
 * ```tsx
 * const ref = useRef(null);
 * const { width, height } = useElementSize(ref);
 * return <div ref={ref}>Size: {width} x {height}</div>;
 * ```
 */
export declare function useElementSize<T extends HTMLElement>(ref: RefObject<T>): ElementSize;