/**
 * Compares two strings in a localized manner, taking into account special characters.
 * The order is defined as: a-z å ä æ ö ø (case-insensitive, with lowercase before uppercase).
 * Characters not in this set are compared based on their Unicode code points after removing accents.
 * @param {string} a - The first string to compare.
 * @param {string} b - The second string to compare.
 * @returns {number} Negative if a < b, positive if a > b, zero if equal.
 */
export function localizedCompare(a: string, b: string): number;
/**
 * Creates a comparator function for sorting objects by a specific property or properties.
 * The property values are compared using localized string comparison.
 * When given an array of properties, sorts by the first property, then by the second if equal, etc.
 * Each property can be a string or an object with a `key` and optional `order` ('asc' | 'desc', defaults to 'asc').
 * @param {string|{key: string, order?: 'asc'|'desc'}|Array<string|{key: string, order?: 'asc'|'desc'}>} prop - The property name(s) to compare by.
 * @returns {(a: Object, b: Object) => number} A comparator function that accepts two objects and returns their sort order.
 * @example
 * arr.sort(localizedCompareBy('title'))
 * arr.sort(localizedCompareBy(['lastName', 'firstName']))
 * arr.sort(localizedCompareBy({ key: 'firstName', order: 'desc' }))
 * arr.sort(localizedCompareBy([{ key: 'lastName', order: 'asc' }, { key: 'firstName', order: 'desc' }]))
 */
export function localizedCompareBy(prop: string | {
    key: string;
    order?: 'asc' | 'desc';
} | Array<string | {
    key: string;
    order?: 'asc' | 'desc';
}>): (a: any, b: any) => number;