/**
 * Removes consecutive doubles.
 * If no argument is provided, standard !== will be used to compare both values.
 * If a mapping fn is provided, the result of the mapping fn will be compared using !==,
 * which means the mapping function should produce a 'simple' types like number or string.
 *
 * (The alternative option would have been to pass 2 arguments to the compare fn and if
 * it returns true, the elements would be considered equal)
 *
 * @example
 * ```typescript
 *    pipe(
 *      itr8.itr8FromArrayAsync([ 1, 2, 2, 2, 3, 4, 4, 3 ]),
 *      itr8.dedup(), // => [ 1, 2, 3, 4, 3 ]
 *    );
 * ```
 * @example
 * ```typescript
 *    pipe(
 *      itr8.itr8FromArrayAsync([ { id: 1 }, { id: 2 }, { id: 2 }, { id: 3 }, { id: 4 }, { id: 4 }, { id: 3 } ])
 *      itr8.dedup((a:{ id:number }) => id ) // => [ [ { id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }, { id: 3 } ];
 *    );
 * ```
 *
 * @param mapFn
 *
 * @category operators/general
 */
declare const dedup: <TIn>(mapFn?: ((v: TIn) => any) | undefined) => import("../../types.js").TTransIteratorSyncOrAsync<TIn, boolean>;
export { dedup };