import { FlowSubject } from '../FlowSubject';
import type { Action, Reducer, ReducerWithInitialState } from '../types';
/**
 * React hook that creates and memoises a {@link FlowSubject} from a reducer and
 * an initial state. The subject is created once and persists for the lifetime
 * of the component.
 *
 * @template S - The state type.
 * @template A - The action type.
 * @param reducer - A reducer function.
 * @param initial - The initial state value.
 * @returns A stable `FlowSubject` instance.
 *
 * @example
 * ```tsx
 * const subject = useObservable(myReducer, { count: 0 });
 * subject.next({ type: 'increment' });
 * ```
 */
export declare function useObservable<S, A extends Action = Action>(reducer: Reducer<S, A>, initial: S): FlowSubject<S, A>;
/**
 * React hook overload that accepts a reducer with a built-in initial state.
 *
 * @template S - The state type.
 * @template A - The action type.
 * @param reducer - A `ReducerWithInitialState` (e.g., created by `createReducer`).
 * @returns A stable `FlowSubject` instance.
 */
export declare function useObservable<S, A extends Action = Action>(reducer: ReducerWithInitialState<S, A>): FlowSubject<S, A>;