import type { ObservableValue, ValueChangeCallback } from './observable-value.js';
export type ValueObserverOptions<T> = {
    filter?: (nextValue: T, lastValue: T) => boolean;
};
/**
 * Subscription handle returned by {@link ObservableValue.subscribe}. Disposing
 * the observer unsubscribes the callback from the observable; disposing the
 * underlying {@link ObservableValue} drops every observer and renders all
 * existing handles inert.
 */
export declare class ValueObserver<T> implements Disposable {
    readonly observable: ObservableValue<T>;
    callback: ValueChangeCallback<T>;
    readonly options?: ValueObserverOptions<T> | undefined;
    [Symbol.dispose](): void;
    constructor(observable: ObservableValue<T>, callback: ValueChangeCallback<T>, options?: ValueObserverOptions<T> | undefined);
}
//# sourceMappingURL=value-observer.d.ts.map