Change of the mutability oif PluginAudioProcessor.activate for main_thread

[anton-k]

In recent version there is an API change. main_thread argument became immutable.
This makes it impossible to pass channels from main to audio thread. I used to create rtrb channels
for communication between UI and audio threads. And &mut main_thread on activation of the audio thread
allows to give ownership of the Producer or Consumer channel with this pattern:

struct PluginMainThread {
  ...
  audio_channel: Option<FromUiConsumer>
  ...
}

And inside the activate if main_thread is mutable I can give ownership of the consumer to the audio thread:

   fn activate(main_thread: &mut PluginMainThread, ...) {
      ... 
      AudioThread {
        fro_ui_consumer: main_thread.audio_channel.take()
      }

  }

and with the new version it's not possible. And I don't know how to pass the consumers/producers to audio thread.
Is it possible to do it in some another way?

[edwloef]

Can you maybe use Cell<Option<FromUiConsumer>> and Cell::take there?