[ncmncm]

If you are not using classes, you are not using OO at all, by definition.

That does necessarily not mean you are programming badly, although you might be. But restricting yourself to STL and smart pointers does very strongly resemble Java Disease. You might as well switch to Java.

[pjmlp]

Definition by whom, certainly not by CS and the innumerous SIGPLAN papers and variations on what OOP means since Simula came into the world.