title: Is it good idea to make std::regex static?
body: <p>I use <code>std::regex</code> created from string literal like this:</p>
  
  <pre><code>std::regex vowel_re("a|e|i|o|u");
  </code></pre>
  
  <p>Is it good idea to make it <code>static</code> to save construction time or even <code>static const</code>? This regex is most likely will be reused.</p>