If you know C++, you almost know C. Experience with C gets you another brag – one character long, so it should fit! – on your resume. C is popular for operating systems and embedded systems, and there are a lot of libraries in it.
SDL/SSDL
cin and cout
& parameters
bool (use int instead)
constexpr (use const instead)
There are no classes, exceptions, overloaded operators, templates, or namespaces. structs exist but don’t have member functions or public/private/protected sections (it’s all public).