rust/src/test/compile-fail/infinite-instantiation.rs

// error-pattern: overly deep expansion
// issue 2258

trait to_opt {
    fn to_option() -> option<self>;
}

impl of to_opt for uint {
    fn to_option() -> option<uint> {
        some(self)
    }
}

impl<T:copy> of to_opt for option<T> {
    fn to_option() -> option<option<T>> {
        some(self)
    }
}

fn function<T:to_opt>(counter: uint, t: T) {
    if counter > 0u {
        function(counter - 1u, t.to_option());
    }
}

fn main() {
    function(22u, 22u);
}