import { Observable } from 'rxjs/internal/Observable';
import { OperatorFunction } from 'rxjs/internal/types';
export declare type Status = 'succeeded' | 'failed' | 'pending';
export interface Http<Req, Res> {
    status: Status;
    req: Req;
    res?: Res;
    error?: any;
}
/**
 * Wraps ajax calls with a status: pending, succeeded or failed.
 * This pipe function is based on switch map, so all previous requests
 * in pending state will be cancelled by emitting a new one.
 *
 * Returned data holds information about status, response and initial request.
 *
 * @param withAjax - transformation function from Request to Observable Response.
 */
export declare function http<Req, Res>(withAjax: (req: Req) => Observable<Res>): OperatorFunction<Req, Http<Req, Res>>;