Method ~awaitable_spsc_queue

example/spsc.cpp:25–32

if the queue gets destroyed, destroying the awaiters is all we can do.

  // if the queue gets destroyed, destroying the awaiters is all we can do.
  ~awaitable_spsc_queue()
  {
    if (auto r = reader.load(); r != nullptr)
      std::coroutine_handle<void>::from_address(r).destroy();

    if (auto w = writer.load(); w != nullptr)
      std::coroutine_handle<void>::from_address(w).destroy();
  }
  // to avoid locks, put the coroutine handles into atomics.
  std::atomic<void*> reader{nullptr}, writer{nullptr};