title: Forward variadic arguments for a UIAlertView
body: <p>I'm trying to set up a very simple <code>UIAlertView</code> with a text edit, an Ok and a cancel button, and I want to disable the Ok button based on the content of the text edit.</p>
  
  <p>To be able to retain the delegate so that he doesn't go away before the alert view (and thus cause a crash as soon as the user does something with the alert view), I've subclassed it. Now, I want to be able to forward the <code>otherButtonTitles</code> argument from my init method to the <code>UIAlertView</code> init method, but for some reasons, simply doing that: </p>
  
  <pre><code>- (id)initWithTitle:(NSString *)title
              message:(NSString*)message
             delegate:(id /*&lt;UIAlertViewDelegate&gt;*/)delegate
    cancelButtonTitle:(NSString *)cancelButtonTitle
    otherButtonTitles:(NSString *)otherButtonTitles, ... {
  
      if (self = [super initWithTitle:title 
                              message:message 
                             delegate:delegate 
                    cancelButtonTitle:cancelButtonTitle 
                    otherButtonTitles:otherButtonTitles, nil]) {
          //stuff
      }
  </code></pre>
  
  <p><em>only adds the first element of the args to the alert view</em>. I've found that I can actually manually add the buttons to the alert view using this:</p>
  
  <pre><code>va_list args;
  va_start(args, otherButtonTitles);
  for (NSString *buttonTitle = otherButtonTitles; buttonTitle != nil; buttonTitle = va_arg(args, NSString*)) {
    [self addButtonWithTitle:buttonTitle];
  }
  va_end(args);
  </code></pre>
  
  <p>but then, my <code>alertViewShouldEnableFirstOtherButton</code> delegate method isn't called anymore, <a href="https://stackoverflow.com/a/20501090/1594913"><strong>with the probable explanation in this post</strong></a>.</p>
  
  <p>Thus, how can I forward correctly my <code>otherButtonTitles</code> to the <code>UIAlertView</code> init method correctly?</p>