export type Updater<T> = (updater: T | ((origin: T) => T), ignoreDestroy?: boolean) => void;
/** We only think `undefined` is empty */
export declare function hasValue(value: any): boolean;
/**
 * Similar to `useState` but will use props value if provided.
 * Note that internal use rc-util `useState` hook.
 */
export declare const useMergedState: <T, R = T>(defaultStateValue: T | (() => T), option?: {
    defaultValue?: T | (() => T) | undefined;
    value?: T | undefined;
    onChange?: ((value: T, prevValue: T) => void) | undefined;
    postState?: ((value: T) => T) | undefined;
} | undefined) => [R, Updater<T>];