How to build a SAFEARRAY of pointers to VARIANTs?

c++ com variant safearray
Serge Weinstock picture Serge Weinstock · Nov 25, 2009 · Viewed 13.8k times · Source

I'm trying to use a COM component with the following method:

HRESULT _stdcall Run(
    [in] SAFEARRAY(BSTR) paramNames,
    [in] SAFEARRAY(VARIANT *) paramValues
    );

How can I create in C/C++ the paramValues array?

Answer

Anonymous Coward picture Anonymous Coward · Jun 3, 2011

Adding to the answers above for reference by future readers: In IDL, SAFEARRAY(...) means a pointer to an array descriptor. But in C++, SAFEARRAY means an array descriptor. So IDL's SAFEARRAY(...) is really C++'s SAFEARRAY *. This confused me to no end. To make things even more interesting, VB always passes arrays by reference. So VB's () As Long is SAFEARRAY<int32_t> ** in C++. (I don't know if there actually is a commonly used header that allows you to specify the type as a template parameter, but I inserted it for clarity.)

Related questions

The #include<iostream> exists, but I get an error: identifier "cout" is undefined. Why?

I learn C++ and COM through the books. In the IDE MS Visual Studio 2012 I have created new empty C++ project, and added some existing files to it. My CPP file contains #include<iostream> row, but in editor …

Read More
BSTR to std::string (std::wstring) and vice versa

While working with COM in C++ the strings are usually of BSTR data type. Someone can use BSTR wrapper like CComBSTR or MS's CString. But because I can't use ATL or MFC in MinGW compiler, is there standard code snippet …

Read More
COM(C++) programming tutorials?

Are there any good sites for learning C++/COM from the ground up? I'm looking for something like a crash course with perhaps two weeks' worth of content. The course can assume knowledge in standard C/C++, or at least …

Read More