[in] Count of elements in the PROPVARIANT array (rgvars).
[in] Pointer to an initialized array of PROPVARIANT structures for which any deallocatable elements are to be freed. On exit, all zeroes are written to the PROPVARIANT structure (thus tagging them as VT_EMPTY).
FreePropVariantArray calls PropVariantClear on an array of PROPVARIANT structures to clear all the valid members. All valid PROPVARIANT structures are freed. If any of the PROPVARIANT structures contain illegal VT types, valid members are freed and the function returns STG_E_INVALIDPARAMETER.
Passing NULL for rgvars is legal, and produces a return code of S_OK.