Can anyone please suggest me how can i generate class diagram from VC++ source code using visual studio
Sorry for my late reply. I think you have posted your message in the wrong place (you should put the message in SDE forum but here is VP-UML).
The SDE Professional Edition (or above) for Visual Studio (SDE PE-VS) supports code synchronization for VC++, you can find out details of reversing .NET code by code sync from http://188.8.131.52/media/documents/sde41vsug1/html/012_Java_Round_Trip_Engineering/012_Java_Round_Trip_Engineering.html#toc-0-1
BTW, you can still reverse VC++ to class diagram in VP-UML using Instant Reverse (available in Standard Edition or above). But since VP-UML only supports reversing source code of ANSI C++ but not Visual C++, you need to compile your VC+ code to dll / exe file and then reverse it to class diagram through Tools > Instant Reverse > .NET dll or exe files. More details can be found at http://184.108.40.206/media/documents/vpuml61ug1/html/Chapter_9_Instant_Reverse/Chapter_9_Instant_Reverse.html#toc-0-3
*Code sync will update the changes made in code/models, but Instant Reverse will overwrite all models every time you run it.
If there is any further inquiry, please do not hesitate to ask.