title: UIFont.monospacedDigitSystemFontOfSize() not really monospaced?
body: <p>I wanted to use SF's monospaced digits font to display an integer number in a text field by changing its font as follows:</p>
  <pre><code>textField.font = UIFont.monospacedDigitSystemFont(textField.font!.pointSize, weight: UIFont.Weight.semibold)
  </code></pre>
  <p>But if I set the text of the text field in a 60Hz frequency, this is the result:</p>
  <p><a href="https://i.stack.imgur.com/9HCke.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9HCke.gif" alt="SF monospaced" /></a></p>
  <p>The width of the text is clearly not constant for a same amount of digits so it is moving all jittery because the text field is constrained to &quot;leading&quot; and &quot;trailing&quot; of the image underneath.
  <strong>Why is this the case and how to fix it?</strong></p>
  <p>Another truly monospaced font like &quot;Menlo&quot; is behaving correctly:</p>
  <p><a href="https://i.stack.imgur.com/fcEZ5.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fcEZ5.gif" alt="Menlo" /></a></p>