bstr

When calling a function that expects a BSTR it'd be nice to be able to write something like: iFoo->function( bs"HELLO" ); However the only workaround I'm aware of is to use a wrapper that calls SysAllocString etc., e.g.: iFoo->function( WideString(L"HELLO").c_bstr() ); which is kind of ugly. Is there actually such an option to create a BSTR literal? Motivation: easier-to-read code, and faster runtime performance by avoiding an allocation and deallocation. Clarification: I am only talking about situations where the caller (i.e. us) has ownership of the BSTR, for example: calling a function that

From book ATL Internals , I knew BSTR is different from OLECHAR*, and there are CComBSTR and CString for BSTR. According MSDN Allocating and Releasing Memory for a BSTR , I knew memory management responsibility for caller/callee. Take this line from MSDN, HRESULT CMyWebBrowser::put_StatusText(BSTR bstr) I still do not know how to handle bstr properly in my implementation. Since I still have a basic question for BSTR -- should we treat bstr as a value (like int) or as a reference (like int*), at least on COM interface boundary. I want to convert BSTR as soon as possible to CString/CComBSTR in

I have a BSTR object that I would like to convert to copy to a wchar__t object. The tricky thing is the length of the BSTR object could be anywhere from a few kilobytes to a few hundred kilobytes. Is there an efficient way of copying the data across? I know I could just declare a wchar_t array and alway allocate the maximum possible data it would ever need to hold. However, this would mean allocating hundreds of kilobytes of data for something that potentially might only require a few kilobytes. Any suggestions? Euro Micelli First, you might not actually have to do anything at all, if all you

I'm working with third-party COM object that has some of its methods passing values back as BSTR pointer. Since VBscript supports only Variant type attempts to use in a way like Object.Method(sMyString) reasonably end with "Type mismatch" error. I suspect this error is generated by the COM object itself rather then VBscript interpreter since the object gets string instead of pointer. I tried to workaround it defining array of strings but it's still the same error. So I was wondering if someone had similar problem and what workarounds were utilized. Just to emphasize. I DO NOT have control over

I have this code in my VB6 app: Private Declare Function FileGetParentFolder Lib "Z-FileIO.dll" _ (ByVal path As String) As String Output.AddItem FileGetParentFolder(FileText.Text) Output is a list, FileText is a text field containing a file path. My C++ DLL contains this function: extern "C" BSTR ZFILEIO_API FileGetParentFolder(Path p) { try { return SysAllocString(boost::filesystem::path(p).parent_path().c_str()); } catch (...) { return SysAllocString(L""); } } where Path is typedef'd as LPCSTR . The argument comes into my DLL perfectly, but whatever I try to pass back, the VB6 app shows