Yup, don&#x27;t do shared mutable state. It is the enemy. Avoid it like the plague.<p>I really love value semantics with structs in swift, it&#x27;s almost always the right thing, and generally very clear when it isn&#x27;t.<p>If anyone ever programmed so that<p><pre><code>  int a = 15 
  int b = a
  b = 17
  assert(a == 17)
</code></pre>
meant that a was now 17 they&#x27;d call it insane, I have no idea why anyone would want that as the default behavior.