import { type EffectCallback } from 'react';
/**
 * Executes a handler function only once when the component mounts.
 * Equivalent to useEffect with an empty dependency array.
 * @param handler - The function to execute on component mount
 */
export declare const useOnMount: (handler: EffectCallback) => void;
/**
 * Executes a handler function only once when the component mounts, before DOM updates.
 * Similar to useOnMount but uses useLayoutEffect for synchronous execution.
 * Useful for DOM measurements or preventing visual flicker.
 * @param handler - The function to execute on component mount
 */
export declare const useOnMountLayout: (handler: EffectCallback) => void;