const _String = String

export default _String.fromCodePoint ||
  function stringFromCodePoint() {
    var MAX_SIZE = 0x4000
    var codeUnits = []
    var highSurrogate
    var lowSurrogate
    var index = -1
    var length = arguments.length
    if (!length) {
      return ''
    }
    var result = ''
    while (++index < length) {
      var codePoint = Number(arguments[index])
      if (
        !isFinite(codePoint) || // `NaN`, `+Infinity`, or `-Infinity`
        codePoint < 0 || // not a valid Unicode code point
        codePoint > 0x10ffff || // not a valid Unicode code point
        Math.floor(codePoint) != codePoint // not an integer
      ) {
        throw RangeError('Invalid code point: ' + codePoint)
      }
      if (codePoint <= 0xffff) {
        // BMP code point
        codeUnits.push(codePoint)
      } else {
        // Astral code point; split in surrogate halves
        // http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
        codePoint -= 0x10000
        highSurrogate = (codePoint >> 10) + 0xd800
        lowSurrogate = (codePoint % 0x400) + 0xdc00
        codeUnits.push(highSurrogate, lowSurrogate)
      }
      if (index + 1 === length || codeUnits.length > MAX_SIZE) {
        result += String.fromCharCode.apply(null, codeUnits)
        codeUnits.length = 0
      }
    }
    return result
  }