Yep. If you had a C program you were automatically already using C++. You could just suddenly start to use the extra features where you wanted them. For that

Yep. If you had a C program you were automatically already using C++. You could just suddenly start to use the extra features where you wanted them. For that it was great. If it had been D instead, an actual new version of C designed to incorporate new features, instead of C++, additional features on top of C, it probably would be less reviled but there would have been a lot more resistance to adoption.