  BasicWriter<Char>::fill_padding(
    CharPtr buffer, unsigned total_size,
    std::size_t content_size, wchar_t fill) {
  std::size_t padding = total_size - content_size;
  std::size_t left_padding = padding / 2;
  Char fill_char = internal::CharTraits<Char>::cast(fill);
  std::uninitialized_fill_n(buffer, left_padding, fill_char);
  buffer += left_padding;
  CharPtr content = buffer;
  std::uninitialized_fill_n(buffer + content_size,
                            padding - left_padding, fill_char);
  return content;
}
Unknown