rustHow to catch a panic in a Rust thread?

Catching a panic in a Rust thread can be done using the catch_unwind function. This function will return a Result type, with Ok if the thread completed successfully, and Err if the thread panicked.

use std::thread;

let result = thread::spawn(|| {
    panic!("Panic!");
}).join();

let unwind_result = result.unwrap_or_else(|_| {
    thread::catch_unwind(|| {
        println!("Caught panic!");
    })
});

match unwind_result {
    Ok(_) => println!("Thread completed successfully"),
    Err(_) => println!("Thread panicked"),
}

Output example

Caught panic!
Thread panicked

Code explanation

• thread::spawn: creates a new thread and returns a JoinHandle
• panic!: macro to cause a panic
• join: method on JoinHandle to wait for the thread to finish
• unwrap_or_else: method on Result to handle the Err case
• catch_unwind: function to catch a panic in a thread
• match: to handle the Result returned by catch_unwind

Helpful links

• std::thread::catch_unwind

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