fn main() {
    loop {
        ();
        ();
    }

    'label: loop
    // loop comment
    {
        ();
    }

    cond = true;
    while cond {
        ();
    }

    'while_label: while cond {
        // while comment
        ();
    }

    for obj in iter {
        for sub_obj in obj {
            'nested_while_label: while cond {
                ();
            }
        }
    }

    match some_var {
        // match comment
        pattern0 => val0,
        pattern1 => val1,
        pattern2 | pattern3 => {
            do_stuff();
            val2
        }
    };
}