/**
 * Set by {@link requireAllCustomElementsToBeDeclarativeElements} and read in the HTML tagged
 * template function.
 *
 * @category Internal
 */
export declare let declarativeElementRequired: boolean;
/**
 * Calling this requires all custom element children to be declarative elements defined by
 * element-vir.
 *
 * @category Util
 */
export declare function requireAllCustomElementsToBeDeclarativeElements(): void;