Normalize the case of array keys in PHP

Is there a "better" way (built-in function, better algorithm) to normalize the case of all the keys in a PHP array? Looping though and creating a new array works ``` $new = array(); foreach( $old as $key=>$value) { $key = strToLower($key); if(!array_key_exists($key,$new) { $new[$key] = $value; } else { throw new Exception('Duplicate Key Encountered'); } } ``` but it seems like these should be a way to do this "in place". Update: It looks like there is a built in, the not deceptively named yet somehow missed by me `array_change_key_case`. I'd still be interesting in seeing algorithmic approaches that would let you better handle what happens when you hit "duplicate" keys.