#310 ATL CString issues

[Alexander Riccio]

This appears related to #293. There's something weird going on, and I can't compile WTL v10 as of now because of it. I have a gut feeling that it has something to do with VS2019, but I can't say for sure right now.

Currently, compiling my app with WTL gives a whole bunch of errors about ATL::CString:

C2039 'CString': is not a member of 'ATL' windirstat ...\wtl.10.0.8280\lib\native\include\atlwinx.h

As best as I can tell, there is no CString in the ATL namespace - only CStringT (the base template class)... whereas in C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.20.27508\atlmfc\include\afxstr.h:103 there's this:

typedef ATL::CStringT< wchar_t, StrTraitMFC< wchar_t > > CStringW;
typedef ATL::CStringT< char, StrTraitMFC< char > > CStringA;
typedef ATL::CStringT< TCHAR, StrTraitMFC< TCHAR > > CString;

Which is presumably what you want. Since CString here is typedefd outside the ATL namespace, it won't work.

I've tried a simple/ugly using ATL::CString = ATL::CStringT< TCHAR, StrTraitMFC< TCHAR > >;, and the more complex/ugly:

namespace ATL {
    using CString = ATL::CStringT< TCHAR, StrTraitMFC< TCHAR > >;
}

and many variations thereof in my headers, but it's not working. So the fix isn't really simple, and I'll have to revert for now.

[Nenad Stefanovic]

There must be something wrong with your setup or your project. I don't see that with VS2019 or older VS/ATL.

afxstr.h is for MFC, you will find typedef for ATL in atlstr.h:

typedef CAtlString CString;

Please provide more info about what is going on.

[Alexander Riccio]

Aha! Now we're getting somewhere. In that file the code is:
```
#ifndef _AFX
typedef CAtlStringW CStringW;

ifdef _ATL_USE_WINAPI_FAMILY_DESKTOP_APP

typedef CAtlStringA CStringA;

endif // _ATL_USE_WINAPI_FAMILY_DESKTOP_APP

typedef CAtlString CString;

endif

`` However, since I'm plugging this into a mostly MFC application (because I hate MFC),_AFXis defined. In the long run, this should be fixed, but in the meantime, should I just#undef _AFX` (or will that break everything else?)

[Nenad Stefanovic]

Ah, I didn't know that you are actually using MFC. In that case you need to add this line before including atlapp.h:

namespace ATL { using ::CString; };

The compiler will now be able tu use MFC's CString as ATL::CString

Cheers,
Nenad