XOP Wave Parameters question

Hi!

I have some difficulties understanding the XOP Manual 6.30 on page 118 about Wave Parameters and testing the wave handle. I am not sure how can I distinguish these two cases:

1. the input wave parameter is NULL due to the user passing an uninitialized wave reference (in this case I want my XOP operation to fail with an error message)

2. the user has used * in place of a wave name (in this case this would mean to use some default behavior of the XOP operation)

As far as I understand the manual in both cases the returned wave handle is NULL and therefore one cannot distinguish the two cases. Is this correct or am I misunderstanding something here?

Thank you very much for your help!

Gregor
You have understood it correctly. There is no way to distinguish these two cases.

Usually NULL is an error. Treating it as meaning default is almost never used. If you are concerned about the ambiguity then don't support NULL as meaning default - just treat it as an error.