[Article] C++20 Practical Coroutines - yield

yield.cc

awaitable_handoff yield_value(utils::AwaitableData *data) {
  if (data == nullptr)
    return awaitable_handoff(std::noop_coroutine());

  for (auto &em : emitters_) {
    em->notify_departure(data);
  }
  return awaitable_handoff(data->continuation);
}