pub trait MonitoringSystem {} // 1. Modified AlertReceiver trait: // - Removed the problematic `clone` method. // - Added `box_clone` which returns a Box. pub trait AlertReceiver { type M: MonitoringSystem; fn install(&self, sender: &Self::M) -> Result<(), String>; // This method allows concrete types to clone themselves into a Box fn box_clone(&self) -> Box>; } #[derive(Clone)] struct Prometheus{} impl MonitoringSystem for Prometheus {} #[derive(Clone)] // Keep derive(Clone) for DiscordWebhook itself struct DiscordWebhook{} impl AlertReceiver for DiscordWebhook { type M = Prometheus; fn install(&self, sender: &Self::M) -> Result<(), String> { // Placeholder for actual installation logic println!("DiscordWebhook installed for Prometheus monitoring."); Ok(()) } // 2. Implement `box_clone` for DiscordWebhook: // This uses the derived `Clone` for DiscordWebhook to create a new boxed instance. fn box_clone(&self) -> Box> { Box::new(self.clone()) } } // 3. Implement `std::clone::Clone` for `Box>`: // This allows `Box` to be cloned. // The `+ 'static` lifetime bound is often necessary for trait objects stored in collections, // ensuring they live long enough. impl Clone for Box> { fn clone(&self) -> Self { self.box_clone() // Call the custom `box_clone` method } } // MonitoringConfig can now derive Clone because its `receivers` field // (Vec>>) is now cloneable. #[derive(Clone)] struct MonitoringConfig { receivers: Vec>> } // Example usage to demonstrate compilation and functionality fn main() { let prometheus_instance = Prometheus{}; let discord_webhook_instance = DiscordWebhook{}; let mut config = MonitoringConfig { receivers: Vec::new() }; // Create a boxed alert receiver let boxed_receiver: Box> = Box::new(discord_webhook_instance); config.receivers.push(boxed_receiver); // Clone the config, which will now correctly clone the boxed receiver let cloned_config = config.clone(); println!("Original config has {} receivers.", config.receivers.len()); println!("Cloned config has {} receivers.", cloned_config.receivers.len()); // Example of using the installed receiver if let Some(receiver) = config.receivers.get(0) { let _ = receiver.install(&prometheus_instance); } }