I did not already know C++. I did already know Java since we did java for our intro class (101/102) and then the next year we did Compiler theory (240). But the professors who know more than me an entry level student designed this structure.

And I did write that same compiler in c++ and sure it was more lines of code but I understood it better.

I've also worked on a scheme interpreter in C++ that someone wrote in a game engine and it wasn't all that complicated.