code: func encodeInt(lat, lng float64) uint64 {
  	latInt := encodeRange(lat, 90)
  	lngInt := encodeRange(lng, 180)
  	return interleave(latInt, lngInt)
  }
docs: // encodeInt provides a Go implementation of integer geohash. This is the
  // default implementation of EncodeInt, but optimized versions are provided
  // for certain architectures.