folly::fbvector<struct iovec> IOBuf::getIov() const {
  folly::fbvector<struct iovec> iov;
  iov.reserve(countChainElements());
  appendToIov(&iov);
  return iov;
}
folly::fbvector<struct iovec> IOBuf::getIov() const {
  folly::fbvector<struct iovec> iov;
  iov.reserve(countChainElements());
  appendToIov(&iov);
  return iov;
}