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c++safearray

How do you get the underlying SAFEARRAY from a CComSafeArray?

I tried the GetSafeArrayPtr() method which returns a LPSAFEARRAY* that a typedef defined as:

typedef /* [wire_marshal] */ SAFEARRAY *LPSAFEARRAY;

I thought I would be able to directly assign this to a SAFEARRAY* variable but the compiler gives this error:

error C2440: '=' : cannot convert from 'LPSAFEARRAY *' to 'SAFEARRAY *'

I found this strange. What am I doing wrong here?

PS: I am doing this inside a C++/CLI dll (if that is of any relevance).

Solution

  • LPSAFEARRAY * is a pointer to SAFEARRAY *, so you need a double pointer, like this:

    {
    CComSafeArray<VARIANT> vArray;
    SAFEARRAY** pArray;
    pArray = vArray.GetSafeArrayPtr();
}

    And then you can pass the SAFEARRAY * to the function that needs it as an argument by dereferencing the pointer returned from CComSafeArray:

    DummyFunction(*pArray);