Method append

extlibs/fmt/include/fmt/format.h:557–562

template <typename T>
template <typename U>
void buffer<T>::append(const U* begin, const U* end) {
  std::size_t new_size = size_ + to_unsigned(end - begin);
  reserve(new_size);
  std::uninitialized_copy(begin, end, make_checked(ptr_, capacity_) + size_);
  size_ = new_size;
}
}  // namespace internal

// A range with an iterator appending to a buffer.