URGENT - template problem - PLEASE HELP

Throughout my project I use class members of type CMap e.g.:
CMap<CString, LPCSTR, C_ApplicationPart*, C_ApplicationPart*> m_mapApplicationPart;

Until yesterday the compiler accepted these constructions. But suddenly it reports the following error for every CMap type defined:
C:\Program Files\DevStudio\VC\MFC\include\afxtempl.h(1478) : error C2664: 'SetAt' : cannot convert parameter 1 from 'const char *' to 'class CString &'

This is very odd.... I've reversed changes I've made, tried old project/workspace files but nothing seems to work. I created a testproject and this project compiles CMap<CString, LPCSTR, typeVal, typeArg> with no problems!!!!

I also tried deleting all temporary files and precompiled header files but nothing seems to work.

Please, please help!

Martin van den Berg
[email protected]

just guess:
the error is raised by SetAt() not by CMap<...> constructor

check the SetAt(), maybe you use
CString str;
SetAt(str, ....);
but not
SetAt((LPCTSTR)str, ....);

just guess...

The compile error occures in
afxtempl.h in the CMap::Serialize method which I do not even use!!!

I am confinced it is not in on of my projects SetAt()'s.

Martin van den Berg
High Tech Automation
The Netherlands
[email protected]

This error means that you are giving an argument of class CString to SetAt(char *) which actually takes parameter of type (char *).

Try with the CSTring member operator as well
operator LPCTSTR ( ) const;
which converts the CString to a C-string

This casting operator provides an efficient method to access the null-terminated C string contained in a CString object. No characters are copied; only a pointer is returned. Be careful with this operator. If you change a CString object after you have obtained the character pointer, you may cause a reallocation of memory that invalidates the pointer.

Or just try extracting the CString values into a buffer of type (char *) and then give it to the function SetAt(buffer); but I think the first is better and faster.

My problem goes beyond casting etc..
The problem is that the compiler reports an error in CMap::Serialize(). In this method the SetAt method is used and this is where the compiler complains about.

I commented this particular piece of code in afxtempl.h out and it now compiles fine! Ofcourse this is a big HACK but it works for the mean time.

I didn't make any mistakes - have a look at the sample in 'Collections: Template-Based Classes.:


Martin van den Berg
High Tech Automation
The Netherlands
[email protected]

That code ought to be OK.

The CMap::SetAt method expects parameter 1 to be an ARG_KEY type, which you've declared to be LPCSTR. The CMap::Serialize method is passing it a CString, which should convert OK (CString has an LPTCSTR conversion).

The error message says SetAt is expecting a CString&, but is getting passed a const char*, which is obviously not correct - it's the reverse of what you'd expect.

I think that somewhere in your program you have mistakenly defined a CMap with the first two template arguments reversed:

CMap<LPCSTR, CString&, C_ApplicationPart*, C_ApplicationPart*> m_mapApplicationPart;

If you put this into your test program it should give the same error.

Nothing else seems to make sense...

Dave

Dave,

Thanks! That was exactly it!!



Martin van den Berg
High Tech Automation
The Netherlands
[email protected]