why use the CreateImpl<T> function

[sameer_h_]

Hi

getting started on understanding the SDK.   Here is an example

PXCMAudioSource audioSrc1;

session.CreateImpl<PXCMAudioSource>(out audioSrc1);

PXCMAudioSource audioSrc2;

audioSrc2 = session.CreateAudioSource();

It's not clear to me from the SDK documentation why use one way to create an audio source vs. the other.   

To me creation of audiotSrc2 makes much more sense than the first one.