Question about C++ knowledge for job

Hi,
I'm currently a 2nd year computer science student and currently taking c++. I am planning on getting an internship hopefully this summer and was wondering how much of a programming language do you need to know to start off on a job ? I know the more you know the better, but for example, C++ and others are very broad languages with many features. What topics in C++ would you guys say should be mastered before being able to say there your "proficient" in the language? Are there any websites that can help me assessment my skills in C++ so I can see if I know as much as I should for job ?
Thanks, additional advice is appreciated.

In my experience, they usually ask stuff about memory and efficiency. In other words, really know your pointers whether in C/C++.

I've been asked about abstract classes, virtual functions, inheritance and even a little template programming. All this and I'm not even a computer science major, I'm an EE.

They just want to test how deep your knowledge is. If necessary start talking a lot about your strongest topic in order to suck up time.