TF_Status* status);

  /// Returns the current write position in `*file`.
  ///
  /// Plugins should ensure that the implementation is idempotent, 2 identical
  /// calls result in the same answer.
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` and return current position if no error.
  ///   * Must set `status` to any other value and return -1 in case of error.

  // POSIX's `ftell` returns `long`, do a manual cast.
  int64_t position = int64_t{ftell(posix_file->handle)};
  if (position < 0)
    TF_SetStatusFromIOError(status, errno, posix_file->filename);
  else
    TF_SetStatus(status, TF_OK, "");

  return position;
}

static void Flush(const TF_WritableFile* file, TF_Status* status) {