Function fill

extlibs/fmt/include/fmt/format.h:1402–1407

template <typename OutputIt, typename Char>
FMT_NOINLINE OutputIt fill(OutputIt it, size_t n, const fill_t<Char>& fill) {
  auto fill_size = fill.size();
  if (fill_size == 1) return std::fill_n(it, n, fill[0]);
  for (size_t i = 0; i < n; ++i) it = std::copy_n(fill.data(), fill_size, it);
  return it;
}

// This template provides operations for formatting and writing data into a
// character range.