I wouldn't expect an intern to write idiomatic modern C++. That looked to me to about what I would expect from a university student that had passing familiarity with C++ from their coursework; there is still an unbelievable amount of "C-with-classes" in active use and pedogogy kicking around.
Given how we used to teach C++ to university first year students back in 1994 - 2000, it still confuses me that there are so bad teachers keeping "C-with-classes" in active use.
Basically, even without the STL, the students would get our department C++ library with the usual stuff (strings, arrays, vectors, bounds checking enabled), and the teaching would be similar to the way that Kate Gregory preaches how to teach modern C++.
