/** Opt-in polling knob accepted by every collection hook. */
export interface PollOptions {
    /** When set (> 0), re-fetch on this millisecond cadence. Off by default. */
    pollMs?: number;
}
export interface Resource<T> {
    data: T;
    error: Error | undefined;
    isLoading: boolean;
    refresh(): Promise<void>;
}
/** Drive one async source into a `{ data, error, isLoading, refresh }` view.
 *
 * `fetcher` must be memoised by the caller (stable across renders while its
 * inputs are unchanged) — refresh, the mount fetch, and the poll all key off
 * its identity. A per-call generation guard drops out-of-order and post-unmount
 * responses so overlapping refreshes (poll + manual + post-mutation) never
 * clobber newer state. `isLoading` reflects only the very first load, so a
 * background poll or refresh never flickers a consumer's initial skeleton. */
export declare function useResource<T>(fetcher: () => Promise<T>, initial: T, { pollMs }?: PollOptions): Resource<T>;