Swift: How to get the value from a AutoreleasingUnsafePointer<NSString?> from a NSScanner?

Question

I don't know how to use the AutoreleasingUnsafePointer. I have the following code:

var myString: AutoreleasingUnsafePointer<NSString?>

myScanner.scanUpToCharactersFromSet(NSCharacterSet.newlineCharacterSet(), intoString: myString)

Now, what should I do to get the string from 'myString'? I know it can be nil, but I couldn't figure out a way to get the string value in case it wasn't nil. And the Swift unwrapping technique just only works with the Optional type.

Thanks!

Answer 1

If the second parameter of scanUpToCharactersFromSet is declared as autoreleasing unsafe pointer, i.e. AutoreleasingUnsafePointer<NSString?> you should be able to invoke your function without making a pointer explicitly. Swift lets you use & operator on an NSString? variable to produce an autoreleasing unsafe pointer, like this:

var str : NSString? = nil
myScanner.scanUpToCharactersFromSet(NSCharacterSet.newlineCharacterSet(), intoString:&str)

This would give you str as a "normal" optional NSString, which you can unwrap using the regular unwrapping operators.