title: Character classes in notepad++ regex search
body: <p>The following search works in notepad++ v. 7.5.9 on my laptop:</p>
  
  <pre><code>[[:space:]]
  </code></pre>
  
  <p>The same search does not produce any results in notepad++ v. 7.5.7 installed on the computer at work. Unless the classes of the form <code>[[:name:]]</code> were added in versions 7.5.8-7.5.9, what could explain this difference in behavior? </p>