Then you still can't forget and do this:

    lock(lk_var) lock(lk_var2)
    {
        lk_var = lk_var2;
    }

Or this:

    lock(lk_var) { lock(lk_var2 { lk_var = lk_var2; } }

Using the pre-processor to solve a regular, every day, hum-drum, solved-a-billion-times RAII problem is bad news.