Re: How to pass a reference to a CComBSTR

"Heinz Ozwirk" <hozwirk.SPAM@xxxxxxxx> wrote in message news:42ec8069$0$29078$9b4e6d93@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
"Steve Franks" <please@xxxxxxxxxxxxxxxxx> schrieb im Newsbeitrag news:_t6dnYV4EPK_V3bfRVn-qg@xxxxxxxxxxxxxx
I have a CComBSTR variable in function A. I want to pass this variable to function B by REFERENCE, so that function B can update this variable with a new string it calculates.

I'm passing in my CComBSTR like this:  myfunction(& myCComBSTRvar)
 and myfunction looks like this:
void myfunction(CComBSTR *myCComBSTRvarToUpdate) {}

This is not passing by reference - you are passing pointers. To pass by reference yous should declare myfunction as

   void myfunction(CComBSTR& myModifiableVariable)...

and call it like

   myfunction(myCComBSTRvar);

Some wise guy at MS thought it to be a good idea to overload operator& to make a CComBSTR easyly mix with plain BSTR. But by doing that he made it impossible to get the address of a CComBSTR itself. If you only use CComBSTR as a wrapper for BSTR, you should have a look at _bstr_t. 

To my best knowledge, the solution would be using the m_str itself.


.

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