Rust tail call test

tailcall.rs

// use tail-call only, but stack overflow occur
fn recur(i : int) {
  if i!=0 {
    recur(i-1);
  }
}

fn main() {
    recur(1000000);
}

// Result ----
// rust: task 7f99a2d00220 ran out of stack
// rust: domain main @0x7f99a3800010 root task failed

rust -O tailcall.rs will do TCO!!