title: Safe integer parsing in Ruby
body: <p>I have a string, say <code>'123'</code>, and I want to convert it to the integer <code>123</code>.</p>
  
  <p>I know you can simply do <code>some_string.to_i</code>, but that converts <code>'lolipops'</code> to <code>0</code>, which is not the effect I have in mind. I want it to blow up in my face when I try to convert something invalid, with a nice and painful <code>Exception</code>. Otherwise, I can't distinguish between a valid <code>0</code> and something that just isn't a number at all.</p>
  
  <p><strong>EDIT:</strong> I was looking for the standard way of doing it, without regex trickery.</p>