/**
 * Copy plain text to the clipboard using a throwaway button element.
 *
 * @param text - The text to copy.
 * @param container - The element the temporary clipboard target lives in;
 *   falls back to `document.body` when not a valid object.
 * @returns A promise that resolves once the copy succeeds and rejects on failure.
 * @example
 * await copyText('hello', document.body)
 */
export declare function copyText(text: string, container: Element): Promise<void>;
/**
 * Copy rich content to the clipboard with both HTML and plain-text flavors.
 *
 * @param html - The HTML representation written to the `text/html` flavor.
 * @param plain - The fallback text written to the `text/plain` flavor.
 * @example
 * copyHtml('<b>hello</b>', 'hello')
 */
export declare function copyHtml(html: string, plain: string): void;