Open source is good for your health

Linux helps to code for Windows too

What exactly Variant.ChangeType( VT_NULL ) does? Will it free any memory owned by variant?

Common sense suggests "yes", but looking at all these low level struct-union-macros games I cannot avoid being paranoid sometimes. Unfortunately, MSDN help does not have such level of details and does not have any notions specifically about VT_NULL usage here.

I am glad I've found Wine sources and could check their logic. Assuming their VARIANT_Coerce mimics Windows API logic I can be sure now that memory is freed. Hooray! I do not have to debug _variant_t!