implementing lifetime issues while implementing a concurrent Rust application using `tokio` and `Arc`
I'm wondering if anyone has experience with I'm stuck on something that should probably be simple. I've looked through the documentation and I'm still confused about I am trying to build a simple concurrent application in Rust using the `tokio` library, where I want to share some state between multiple tasks... However, I keep running into lifetime issues that I need to seem to resolve. I'm using `Arc` to share a `HashMap<String, i32>` among the tasks. My current code looks like this: ```rust use std::collections::HashMap; use std::sync::{Arc, Mutex}; use tokio::task; #[tokio::main] async fn main() { let shared_data = Arc::new(Mutex::new(HashMap::new())); for i in 0..5 { let data_clone = Arc::clone(&shared_data); task::spawn(async move { let mut data = data_clone.lock().unwrap(); data.insert(format!("key_{}", i), i); }); } } ``` However, when I run this, I get the following behavior: ``` behavior[E0507]: want to move out of `data_clone` because it is borrowed --> src/main.rs:12:41 | 12 | let mut data = data_clone.lock().unwrap(); | ^^^^^^^^^^^^^^ move occurs because `data_clone` has type `Arc<Mutex<HashMap<String, i32>>>`, which does not implement the `Copy` trait ``` I believe the question lies in how I am handling the `Arc` and the borrow checker. I've tried to adjust the scope of the variables and even used a different method to lock the mutex, but none of these approaches seem to resolve the scenario. What am I missing here? Is there a best practice for sharing mutable state among tasks in `tokio`? Any help would be greatly appreciated! For context: I'm using Rust on Windows. What am I doing wrong? I'm working on a web app that needs to handle this. Is there a better approach? The project is a microservice built with Rust. I'm coming from a different tech stack and learning Rust. Has anyone else encountered this?