title: PostgreSQL - regex issue
body: <p>I'm trying the following instruction and I don't understand the TRUE value returned :</p>
  
  <pre><code>SELECT '1' ~ '(0[1-9])|[10-15]' ;
  
  ?column?
  boolean
  ----------
  t
  </code></pre>
  
  <p>If I make it simplier again, I still don't understand the value returned :</p>
  
  <pre><code>SELECT '1' ~ '[10-15]' ;
  
  ?column?
  boolean
  ----------
  t
  </code></pre>
  
  <p>Thank you for helping !</p>
  
  <p>Thomas</p>