title: Old code gives "Unused parameter" error but never has before now
body: <p>I've opened up some old iOS code and when I try to build it I get an "unused parameter" error for code like this:</p>
  
  <pre><code>- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {
      NSLog(@"Search Bar isn't used in this function");
  }
  </code></pre>
  
  <p>This is the first time I've ever seen an Objective-C compiler spit out errors (not warnings) for this. Since a lot of iOS calls don't necessarily use the passing arguments (examples being a lot of callbacks), I need help in getting rid of this.</p>