/**
 * Safely convert a string value into string union type.
 * @param s string value
 * @param u tuple containing all the values in a string union
 * @returns value of type union
 * @note Outputs error to console if incoming string is not part of string union!
 */
export declare function stringToUnion<U extends ReadonlyArray<string>>(s: string, u: U): (typeof u)[number];
/**
 * Convert a string value into string union type.
 * @param s string value
 * @param u tuple containing all the values in a string union
 * @returns value of type union or undefined if income string is not part of union
 * @note Outputs error to console if incoming string is not part of string union!
 */
export declare function stringToUnionStrict<U extends ReadonlyArray<string>>(s: string, u: U): (typeof u)[number] | undefined;