Undeclared identifier __bridge on xcode

I am trying to convert a CFUUIDRef to a NSString *.

Before, I used the following code, and worked fine.

CFStringRef str = CFUUIDCreateString(NULL, _uuid); # _uuid is of type CFUUIDRef
return (__bridge NSString *) str;

However, after a recent update on Xcode (or other thing that I didn't notice?), the above code gives me the error:

Use of undeclared identifier '__bridge'

So have I did something wrong? How could I solve it?

=== UPDATED ===

The full code:

+ (NSString *)uuidToString:(CFUUIDRef)_uuid {
  CFStringRef str = CFUUIDCreateString(NULL, _uuid); # _uuid is of type CFUUIDRef
  return (__bridge NSString *) str;
}

The uuid is generated by:

uuid = CFUUIDCreate(NULL);