safe to reinterpret_cast vector<CComPtr<>>?

[GeoRanger]

Hello,

I am trying to use CComPtr to manage all of the COM objects in a block of code which uses DirectWrite.

IDWriteFontFace::GetFiles takes an array of pointers to IDWriteFontFile as its second argument. The caller must supply the memory block which will receive the pointers. I want to use std::vector<CComPtr> to manage all of the returned IDWriteFontFile objects. Can I do that as shown in the following code snippet?

Please note that I'm using static_assert to verify that the memory layout of CComPtr is what I expect. Then reinterpret_cast is used to give GetFiles the pointer type it expects, and that pointer type is what I would effectively expect the guts of the vector object to be.

The code is post C++11 so CAdapt isn't needed.

Is this safe and guaranteed to work? If not, is there an alternative method I could use which is better than reverting to raw pointers?

            // Query the number of files.
            UINT32 nFiles = 0;
            ThrowIfFailed(ptrFontFace->GetFiles(&nFiles, nullptr));


            // Allocate storage to hold the files.
            static_assert(sizeof(CComPtr<IDWriteFontFile>) == sizeof(IDWriteFontFile*),
                          "The vector of CComPtr which follows cannot be used safely.");
            std::vector<CComPtr<IDWriteFontFile>> vFontFiles;
            vFontFiles.resize(nFiles);


            // Retreive the files into the allocated storage.
            ThrowIfFailed(ptrFontFace->GetFiles(&nFiles, reinterpret_cast<IDWriteFontFile**>(vFontFiles.data())));

Thank you,
GeoRanger