import type { Result } from './result.js';
type MapErr = {
    <Res extends Result.Any, T>(mapFn: (err: Result.ErrType<Res>) => T): (result: Res) => Result<Result.OkType<Res>, T>;
    <Res extends Result.Any, T>(mapFn: (err: Result.ErrType<Res>) => T, result: Res): Result<Result.OkType<Res>, T>;
};
/**
 * Transform the value inside the `Err` variant of a `Result`.
 *
 * If the input `Result` is an `Err`, the function applies `mapFn` to the error value and returns a new `Result` object
 * with the transformed error value. If the input `Result` is an `Ok`, it simply returns the input `Result` object
 * unmodified.
 *
 * This function is similar to `map`, but instead of transforming the `Ok` value, it transforms the `Err` value.
 *
 * @tags result, transform, transform-value, errors, left-biased
 * @see https://doc.rust-lang.org/core/result/enum.Result.html#method.map_err
 */
export declare const mapErr: MapErr;
export {};