These are not versions of the language, but rather versions of Cfront, which
was the original C++ translator implemented by AT&T. It has become generally
accepted to use these version numbers as if they were versions of the language
itself.
Very roughly speaking, these are the major features:
- 2.0 includes multiple/virtual inheritance and
pure virtual functions
- 2.1 includes semi-nested classes and
delete[] pointerToArray
- 3.0 includes fully-nested classes, templates and i++ vs.
++i
- 4.0 will include exceptions