/**
 * Indicates if there is a grapheme cluster boundary between a and b.
 *
 * Legacy function. Does not cover cases where a sequence of code points is
 * required in order to decide if there is a grapheme cluster boundary, such as
 * emoji modifier sequences and emoji flag sequences. To cover all cases please
 * use `hasGraphemeBreakStrings`.
 *
 * There are two kinds of grapheme clusters: 1) Legacy 2) Extended. This method
 * is to check for both using a boolean flag to switch between them. If no flag
 * is provided rules for the extended clusters will be used by default.
 *
 * @param {number} a The code point value of the first character.
 * @param {number} b The code point value of the second character.
 * @param {boolean=} opt_extended If true, indicates extended grapheme cluster;
 *     If false, indicates legacy cluster. Default value is true.
 * @return {boolean} True if there is a grapheme cluster boundary between
 *     a and b; False otherwise.
 */
export function hasGraphemeBreak(a: number, b: number, opt_extended?: boolean | undefined): boolean;
/**
 * Indicates if there is a grapheme cluster boundary between a and b.
 *
 * There are two kinds of grapheme clusters: 1) Legacy 2) Extended. This method
 * is to check for both using a boolean flag to switch between them. If no flag
 * is provided rules for the extended clusters will be used by default.
 *
 * @param {string} a String with the first sequence of characters.
 * @param {string} b String with the second sequence of characters.
 * @param {boolean=} opt_extended If true, indicates extended grapheme cluster;
 *     If false, indicates legacy cluster. Default value is true.
 * @return {boolean} True if there is a grapheme cluster boundary between
 *     a and b; False otherwise.
 */
export function hasGraphemeBreakStrings(a: string, b: string, opt_extended?: boolean | undefined): boolean;
/**
 * Enum for all Grapheme Cluster Break properties.
 * These enums directly corresponds to Grapheme_Cluster_Break property values
 * mentioned in http://unicode.org/reports/tr29 table 2. VIRAMA and
 * INDIC_LETTER are for the Virama × Base tailoring mentioned in the notes.
 */
export type property = number;
export namespace property {
    const OTHER: number;
    const CONTROL: number;
    const EXTEND: number;
    const PREPEND: number;
    const SPACING_MARK: number;
    const INDIC_LETTER: number;
    const VIRAMA: number;
    const L: number;
    const V: number;
    const T: number;
    const LV: number;
    const LVT: number;
    const CR: number;
    const LF: number;
    const REGIONAL_INDICATOR: number;
    const ZWJ: number;
    const E_BASE: number;
    const GLUE_AFTER_ZWJ: number;
    const E_MODIFIER: number;
    const E_BASE_GAZ: number;
}