This is referred to as a template specialization which you can read about in your favorite C++ book. Unfortunately, VC 6.0's support for templates is weak and sometimes buggy. Moreover, member function templates aren't supported at all when defined outside of the class. Note that VC6 was also written before the official C++ standard was ratifiied in 1998 (both occurred around the same time). You're out of luck IOW (and better off taking the plunge into a later compiler if possible - note however that other potential issues may also surface - non-compliant and potentially buggy C++ code that you could get away with in VC6 isn't so easy in later versions of the compiler - this is for your own good however)