How to Implement Structured Concurrency in Rust

Rust does not have built-in structured concurrency; you must use the tokio crate to manage task lifecycles safely. Add the dependency and wrap your asynchronous tasks in a JoinSet to ensure they complete or cancel together.

[dependencies]
tokio = { version = "1", features = ["full"] }

use tokio::task::JoinSet;

#[tokio::main]
async fn main() {
    let mut set = JoinSet::new();
    
    set.spawn(async { println!("Task 1"); });
    set.spawn(async { println!("Task 2"); });
    
    while let Some(res) = set.join_next().await {
        res.unwrap();
    }
}

Structured concurrency ensures that when a parent task ends, all its child tasks are automatically cleaned up or cancelled. Think of it like a manager who ensures every employee they hired leaves the building when the shift ends, preventing anyone from being left behind. You use this pattern to prevent memory leaks and ensure your application shuts down gracefully.