title: Is u_int64_t available on 32-bit machine?
body: <p>I want to use a <code>u_int64_t</code> variable as search key,</p>
  
  <p>is <code>u_int64_t</code> available on 32-bit machine?</p>
  
  <p>if not, I have to divide this variable into two varibles? then as a search key, it is a bit more troublesome</p>
  
  <p>are there any workaround for this?</p>