title: Objective-C in,out,inout,byref,byval, .. and so on. What are they?
body: <p>I discovered something unfamiliar while reading Objective-C manual for <code>@encoding</code>.</p>
  
  <pre><code>Table 6-2  Objective-C method encodings
  Code Meaning
  r    const
  n    in
  N    inout
  o    out
  O    bycopy
  R    byref
  V    oneway
  </code></pre>
  
  <p>The only thing I know is <code>oneway</code>. What are the others?</p>