title: Order of items in set has been changed, Set, Swift
body: <p>Im creating 2 sets which are containing <code>String</code> like following</p>
  
  <pre><code> let set1 : Set&lt;String&gt;   =   (["07:00", "QShift", "PRN"])
   let set2 : Set&lt;String&gt;   =   (["07:15", "QShift", "PRN"])
  </code></pre>
  
  <p>At first, I am thinking the order of strings in each set will be exactly as same as their orders when being added. However I was wrong about the one of <code>set1</code>, the console gives me this</p>
  
  <pre><code>Printing description of set1:
  ▿ 3 elements
    - [0] : "QShift"
    - [1] : "PRN"
    - [2] : "07:00" { ... }
  
  Printing description of set2:
  ▿ 3 elements
    - [0] : "07:15"
    - [1] : "QShift"
    - [2] : "PRN" { ... }
  </code></pre>
  
  <p>Does anyone know why the order of strings in <code>set1</code> has been changed to <code>QShift, PRN, 07:00</code>?</p>