import { Observable } from 'rxjs';
/** Contains a source observable and exposes properties about that source observable. */
export declare class LoadingSubject<T> extends Observable<T> {
    /** True when the source observable is loading */
    readonly loading: Observable<boolean>;
    /** The error from the source observable or null if no error occured */
    readonly error: Observable<any>;
    /** True if loading or there is an error */
    readonly loadingOrError: Observable<boolean>;
    /** True if the source has at least one value and is not loading and does not have an error */
    readonly resolved: Observable<boolean>;
    constructor(source: Observable<T>, options?: Partial<LoadingSubjectOptions>);
}
/** Options for a loading subject */
export interface LoadingSubjectOptions {
    /** Whenever this observable emits a value, any value, the loading subject will set loading to true */
    loadingWhen: Observable<any>;
    /** When set to true the loading subject's loading observable will default to false */
    defaultOff: boolean;
    /** When set to true the source observable is kept alive even after sending an error */
    guardError: boolean;
}