rust/tests/ui/recursion/recursion-tail-cps.rs

//! Verify that mutually recursive functions use CPS to avoid overflowing the stack.

//@ run-pass

fn checktrue(rs: bool) -> bool {
    assert!(rs);
    return true;
}

pub fn main() {
    let k = checktrue;
    evenk(42, k);
    oddk(45, k);
}

fn evenk(n: isize, k: fn(bool) -> bool) -> bool {
    println!("evenk");
    println!("{}", n);
    if n == 0 {
        return k(true);
    } else {
        return oddk(n - 1, k);
    }
}

fn oddk(n: isize, k: fn(bool) -> bool) -> bool {
    println!("oddk");
    println!("{}", n);
    if n == 0 {
        return k(false);
    } else {
        return evenk(n - 1, k);
    }
}