Converting a swift object to a pointer (and back)

Sometimes it is necessary to convert a swift object to a pointer. This is required in situations, for example, where you need to pass a swift object to a C function that takes a void * (AKA UnsafeMutableRawPointer) parameter. Getting a pointer to a swift class is fairly simple, although it can take a while to find the correct syntax. The following code snipper will convert a Swift NSArray instance to an UnsafeMutableRawPointer, and back to a NSArray without changing the retain count. If you paste the code into a playground, it will print "same array".

	let nsarray = NSArray()
	let nsarrayPointer = Unmanaged.passUnretained( nsarray ).toOpaque()
	let nsarray2 = Unmanaged<NSArray>.fromOpaque( nsarrayPointer ).takeUnretainedValue()
	if( nsarray === nsarray2 )
	{
	print( "same array" )
	}

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