Toll-free bridging and pointer access in Swift

Question

I am porting an App from Objective-C to Swift and I need to use the following method:

CFStreamCreatePairWithSocketToHost(alloc: CFAllocator!, host: CFString!         


        

Answer 1

I worked out how to do it. A few important notes:

1. CMutablePointers will be automatically created if you use the & operator.
2. You can get at the T in an Unmanaged with .getUnretainedValue() and getRetainedValue() (Seems .getUnretainedValue() is analogous to __bridge_transfer)
3. Optionals are automatically initialised to nil.
4. If an optional is nil it will translate into a false condition.

So far I have (untested):

var readStream: Unmanaged?
var writeStream: Unmanaged?

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, host, port, \
&readStream, &writeStream)

if (readStream && writeStream) {
    inputStream = readStream!.takeUnretainedValue();
    outputStream = writeStream!.takeUnretainedValue();
}