import { AsyncIterableX } from './asynciterablex';
export interface TimeInterval<T> {
    value: T;
    elapsed: number;
}
export declare class TimeIntervalAsyncIterable<TSource> extends AsyncIterableX<TimeInterval<TSource>> {
    private _source;
    constructor(source: AsyncIterable<TSource>);
    [Symbol.asyncIterator](): AsyncIterableIterator<{
        value: TSource;
        elapsed: number;
    }>;
}
export declare function timeInterval<TSource>(source: AsyncIterable<TSource>): AsyncIterableX<TimeInterval<TSource>>;