/** Used to compose unicode character classes. */
  var rsAstralRange = '\\ud800-\\udfff',
      rsComboMarksRange = '\\u0300-\\u036f',
      reComboHalfMarksRange = '\\ufe20-\\ufe2f',
      rsComboSymbolsRange = '\\u20d0-\\u20ff',
      rsComboRange = rsComboMarksRange + reComboHalfMarksRange + rsComboSymbolsRange,
      rsVarRange = '\\ufe0e\\ufe0f';
  
  /** Used to compose unicode capture groups. */
  var rsZWJ = '\\u200d';
  
  /** Used to detect strings with [zero-width joiners or code points from the astral planes](http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/). */
  var reHasUnicode = RegExp('[' + rsZWJ + rsAstralRange  + rsComboRange + rsVarRange + ']');
  
  /**
   * Checks if `string` contains Unicode symbols.
   *
   * @private
   * @param {string} string The string to inspect.
   * @returns {boolean} Returns `true` if a symbol is found, else `false`.
   */
  function hasUnicode(string) {
    return reHasUnicode.test(string);
  }
  
  module.exports = hasUnicode;