import type { AsyncErr, ErrResult, Result } from './types';
type ErrType<E> = ErrResult<E>;
declare class Err<E> implements ErrResult<E> {
    readonly error: E;
    constructor(error: E);
    get isOk(): false;
    get isErr(): true;
    get isError(): true;
    get value(): never;
    map(): this;
    mapErr<F>(fn: (error: E) => F): Err<F>;
    chain(): this;
    chainErr<S, F>(next: (error: E) => Result<S, F>): Result<S, F>;
    unwrap(): never;
    unwrapOr<S>(fallback: S): S;
    unwrapOrElse<S>(fallback: (error: E) => S): S;
    unwrapErr(): E;
    unwrapErrOr(): E;
    unwrapErrOrElse(): E;
    unpack(): E;
    match<TR, ER>(okMatcher: (data: never) => TR, errMatcher: (error: E) => ER): ER;
    tap(): this;
    tapErr(fn: (error: E) => void): this;
    [Symbol.iterator](): Generator<E, never>;
    unwrapOrThrow(): never;
    biMap<F>(_: unknown, errFn: (error: E) => F): Err<F>;
    biChain<S, F>(_: unknown, errFn: (error: E) => Result<S, F>): Result<S, F>;
    asTuple(): [ok: false, error: E, value: undefined];
    get [Symbol.toStringTag](): string;
}
export declare const ErrImpl: typeof Err;
export declare const err: <E>(error: E) => ErrType<E>;
export declare const asyncErr: <E>(error: E | Promise<E>) => AsyncErr<E>;
export {};