/**
 * Used to describe the outcome of operations where failure is not an
 * exceptional circumstance and hence does not warrant the use of
 * language-level exception handling.
 */
export type Result<T, E extends {} = Error> = {
    readonly value: T;
    readonly err?: never;
} | {
    readonly err: E;
    readonly value?: never;
};
/**
 * Return the result's value or throw its error.
 *
 * @param result A result to unwrap
 * @returns The result's value
 */
export declare function unwrapResult<T, E extends {} = Error>(result: Result<T, E>): T;
/**
 * Wrap a function that returns the result value instead of the original
 * function's result and throws the error if the function did not succeed.
 *
 * @param fn function that returns a result
 * @returns the result's value, otherwise throws the result's error
 */
export declare function unwrapResultFunctor<Args extends any[], T>(fn: (...args: Args) => Result<T>): (...args: Args) => T;