Wellllll it's more of an abrupt exit rather than a crash, which is still better than eg. silently accessing beyond the end of an array, or ending up with a pointer to nowhere when you thought you had a sane memory reference.

[–] arendjr@programming.dev 4 points 2 days ago (3 children)

“An abrupt exit”, more commonly known as a “crash”.

If you’re going to argue that an exit through panic!() is not a crash, I will argue that your definition of a crash is just an abrupt exit initiated by the OS. In other words, there’s no meaningful distinction as the result is the same.

[–] qaz@lemmy.world 6 points 2 days ago* (last edited 2 days ago) (1 children)

I don't think that's a valid comparison. The behavior does differ when it comes to cleanly releasing resources. Rust's panic performs the drop actions for the current values on the stack, a SIGILL or SIGSEGV crash doesn't.

#[derive(Debug)]
struct MyStruct {}

impl Drop for MyStruct {
	fn drop(&mut self) {
		println!("{:?}", "imagine cleanup here"); // this is called
	}
}

fn main() {
	let a = MyStruct {};
	panic!("panic!");
        println!("{a:?}");
}

Try it yourself

[–] arendjr@programming.dev 7 points 2 days ago

That’s fair, although technically you could catch SIGSEGV and release resources that way too.

Also, given that resources will be reclaimed by the OS regardless of which kind of crash we’re talking about, the effective difference is usually (but not always) negligible.

Either way, no user would consider a panic!() to be not a crash because destructors ran. And most developers don’t either.

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