i am using keil uvision 5.
in c++ it shows
class cdiolog { } extern cdiolog *g_diolog;
it shows an error redeclaration of cdiolog and unreferenced pointer?
Maybe the diolog doesn't like to be spelled diolog?
What does your C++ course book say about how to write code with classes? {} seems rather boring. And doesn't the C++ book contain code that ends with ';' after type declarations? And in your case - exactly where do you think you are referencing your pointer?