code: func adjust(addr uint64, offset int64) (uint64, bool) {
  	adj := uint64(int64(addr) + offset)
  	if offset < 0 {
  		if adj >= addr {
  			return 0, true
  		}
  	} else {
  		if adj < addr {
  			return 0, true
  		}
  	}
  	return adj, false
  }
docs: // adjust shifts the specified address by the signed offset. It returns the
  // adjusted address. It signals that the address cannot be adjusted without an
  // overflow by returning true in the second return value.