last_box_fail.rs

extern mod std;
use std::list::*;

pub fn last_box<T>(l: @List<T>) -> T {
	match *l {
		Nil => fail!(),
		Cons(hd, @Nil) => hd,
		Cons(_, tl) => last_box(tl)
	}
}

#[cfg(test)]
mod tests {
	use super::*;
	use std::list::*;
	
	#[test] #[should_fail]
	fn empty() {
		last_box(@Nil::<int>);
	}
}

/*
Fails with the following error:

	01_lastbox.rs:5:7: 5:9 error: moving out of dereference of immutable @ pointer
	01_lastbox.rs:5 	match *l {
	                	      ^~
	error: aborting due to previous error
*/