so what do u do with an error like:
Two possibilities. One is to edit the library to add a capacity() member, and continue to use that.
The other is to look at how Strings are now implemented, to see that the _capacity (private) field is simply used to determine if a given String object has room to add the new characters. If it doesn't, another (larger) memory allocation is performed, and the existing data copied to the new location, and the old location is freed. Effectively, String objects are now unlimited in size (constrained only by the actual memory available at any given point in time), so the capacity of a string is irrelevant. So, quit asking. There WILL be enough room.