rust/src/test/run-pass/cleanup-copy-mode.rs

// xfail-win32
fn adder(+x: @int, +y: @int) -> int { return *x + *y; }
fn failer() -> @int { fail; }
fn main() {
    assert(result::is_err(&task::try(|| {
        adder(@2, failer()); ()
    })));
}