Method bytes_buffered

cpp/src/arrow/io/buffered.cc:223–223

int64_t BufferedOutputStream::buffer_size() const { return impl_->buffer_size(); }

int64_t BufferedOutputStream::bytes_buffered() const { return impl_->buffer_pos(); }

Result<std::shared_ptr<OutputStream>> BufferedOutputStream::Detach() {
  return impl_->Detach();