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c++safearray

Does SafeArrayAccessData ever return a pointer different from pvData?

I know that SafeArrayAccessData also does locking/unlocking, but never mind that, I'm interested only to know if it ever returns a pointer different from pvData.

For example, this code never triggers the assert (that I could see in my tests):

SafeArrayAccessData(sa, (void**) &ptr);
assert(ptr == sa->pvData);

Does anyone know of a scenario where SafeArrayAccessData would yield a pointer that is not equal to pvData?

Solution

  • The only way the out-parameter pointer set by SafeArrayAccessData() would be other than psa->pvData would be if the function's return value is other than S_OK (e.g. the array could not be locked, in which case the out-parameter's value is unspecified).

    If the function does return S_OK, the out-parameter pointer must equal psa->pvData (after all, what else could it be?).