[dvfjsdhgfv]

I don't believe anyone tries to hide it. Except a couple of well-known cases, C++ is (relatively slightly) slower than C, but it's far more powerful. You can argue about compile times - yes, there is a huge difference here; also some specific features like virtual methods are slow - but overall, C++ is one of the fastest languages available.

[pjmlp]

C++ includes plenty of tools, including a C11 subset, so if it happens to be slower than a bare bones C compiler, the author doesn't know its craft.