title: How can I test when a feature was added to Perl?
body: <p>Are there any services similar to <a href="http://codepad.org/" rel="noreferrer">codepad</a> that will allow you to test Perl constructs on old versions of perl?</p>
  
  <p>Ideally, a system where you could enter an expression and it will tell you the oldest version of perl that it will work with.</p>
  
  <p>Of course it's possible to use CPANTS for this, but that seems like an abuse of the service (if only for making the BackPan bigger).  And it could take several days/weeks to get decent test coverage on old versions.</p>