I am curious: why does this field use/used C++ instead of C for the logic? What benefits does C++ have over C in the domain? I am proficient in C/assembly but completely ignorant of the practices in HFT so please go easy on the explanations!
C++ is more expressive and allows much more abstraction than C. For a long time C++ was the only mainstream language that provided C-level performance as well as rich abstractions, which is why it became popular in fields that require complex domain modeling, like HFT, gamedev, and graphics. (Of course one can debate whether this expressivity is worth the enormous complexity of the language, but in practice people have empirically chosen C++.)
