Is Casey checking two times the DirectSoundCreate? Like, checking all the function, and checking with those parameters in specific? What is going on with this statement?

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if(DirectSoundCreate && SUCCEEDED(DirectSoundCreate(0, &directSound, 0))) { ... }

DirectSoundCreate is a pointer (function pointer).

"DirectSoundCreate" tests if pointer is not NULL. It is equivalent to following expression "DirectSoundCreate != NULL".

"SUCCEEDED(DirectSoundCreate(0, &directSound, 0))" is calling this function pointer and passing result to SUCCEEDED macro. This macro expands to something like this: "DirectSoundCreate(0, &directSound, 0) == S_OK".

So if statement executes following:

Now I get it. Thanks man.