title: Alternatives to the ++ post-increment operator?
body: <p>I'd like to refactor this merge sort without using the legacy ++ in Swift.</p>
  
  <p>When unary operators are used in more complex statements using instance methods and multiple levels I have trouble with the logic. </p>
  
  <p>You cannot simply switch <code>++</code> to <code>+=1</code> because you'll get a <code>Cannot subscript a value of type '[Int]' with an index of type '()'</code> error. </p>
  
  <p>So should I be creating a new mutable copy var and then incrementing that var? Also can I refactor this block using guard even though there is no error checking? Pointless?</p>
  
  <pre><code>if (hidariCount &lt; hidari.count &amp;&amp; (migiCount &gt;= migi.count || hidari[hidariCount] &lt;= migi[migiCount])) {
      sortedArray.append(hidari[hidariCount++])
  } else if (migiCount &lt; migi.count &amp;&amp; (hidariCount &gt;= hidari.count || migi[migiCount] &lt; hidari[hidariCount])) {
      sortedArray.append(migi[migiCount++])
  }
  </code></pre>