Which is something that should probably be added to log4cxx.hw.
On Wed, 2008-04-23 at 23:30 -0500, Curt Arnold wrote:
> On Apr 23, 2008, at 8:12 PM, Jara, Mike SEA wrote:
>
> > I'm having trouble getting (Windows) MFC or ATL CStrings to log
> > properly, when using the LOG4CXX_* macros. For example, this will log
> > the pointer's hex value, rather than the string contents:
> >
> > CString sMyString(_T("Test CString"));
> > LOG4CXX_DEBUG(MyLogger, sMyString);
> >
> > CString does implement a cast operator to LPCTSTR (wchar_t* in my
> > case).
> > If I explicitly call this, the string logs properly:
> >
> > CString sMyString(_T("Test CString"));
> > LOG4CXX_DEBUG(MyLogger, (LPCTSTR)sMyString);
> >
> > I would expect this cast operator to be implicitly called inside
> > MessageBuffer, to make the argument comply with the function
> > signature.
> > I think this is the function that should be called:
> >
> > WideMessageBuffer& MessageBuffer::operator<<(const wchar_t* msg);
> >
> > But when I step through in the debugger, I see that there is a global
> > cast operator called instead. I assume it's a better fit, as far as
> > the
> > compiler's concerned:
> >
> > template<class V>
> > std::ostream& operator<<(MessageBuffer& os, const V& val) {
> > return ((std::ostream&) os) << val;
> >
> > I tried commenting this cast operator out, and then I no longer have
> > to
> > cast my CString! But I'm afraid this was probably put in for a
> > reason,
> > and I hate to just hack something when I don't completely understand
> > it.
> > Does anyone know if I can safetly remove this? Looking at the change
> > list, I see it was added by "carnold" on 11/6/07, revision number
> > 592542.
> >
> > I'm using the last snapshot before the 0.10 release, by the way.
> >
> > Any help would be appreciated.
> >
> > Thanks!
> > Mike
>
>
> The template that you mentioned basically says that when attempting to
> insert, you do not recognize the right hand side as a recognized
> string type (char*, wchar_t*, std::string, std::wstring), then use any
> available insertion operator for a std::ostream and force the rest of
> the expression to be char* based.
>
> What you'd like to have is something like the following in scope:
>
> #if defined(_UNICODE)
> WideMessageBuffer& operator<<(MessageBuffer& buf, const CString& str) {
> return buf << (const wchar_t*) str;
> }
> WideMessageBuffer& operator<<(WideMessageBuffer& buf, const CString&
> str) {
> return buf << (const wchar_t*) str;
> }
> #else
> CharMessageBuffer& operator<<(MessageBuffer& buf, const CString& str) {
> return buf << (const char*) str;
> }
> CharMessageBuffer& operator<<(CharMessageBuffer& buf, const CString&
> str) {
> return buf << (const char*) str;
> }
> #endif
>
> which should take precedence over the fallback insertion operation.
>
--
Dale King <[EMAIL PROTECTED]>
