import type { Rect } from "./Rect.js";
/**
 * Merge a list of rectangles into a single rectangle. If there are no
 * rectangles to merge, then null is returned. Note that, if a single rectangle
 * is supplied, that same rectangle is returned without copying.
 *
 * @returns Returns the merged rectangle, or null if there are no input rectangles
 *
 * @category Helper
 */
export declare function mergeRects(rects: [Rect, ...Rect[]]): Rect;
export declare function mergeRects(rects: []): null;