On page 85 of Don Box book, Essenti

[AliAndAli]

On page 85 of Don Box book, Essential COM, is a code like this:
STDMETHODIMP MyClass::UseIt(VARIANT var) {
VARIANT var2;
VariantInit(&var2);
VariantChangeType(&var2, &var, 0, VT_BSTR);
ustrcpy(m_szSomeDataMember, SAFEBSTR(V_BSTR(&var2)));
VariantClear(&var2);
}

I am wondering what happens if we do not call VariantClear? if VARIANT goes out of scope without calling this function, could it cause memory leak?

Thanks,
Ali

 

[LazyMe]

VariantClear will release any resources held by the VARIANT.
If it contains a VT_BSTR member it will call SysFreeString on the member, if it contains a VT_DISPATCH member it will call Release in the interface etc. If you don't call VariantClear indeed the VARIANT variable will go out of scope, but the data it might be pointing to will not be released.
Greetings,
Rick