C++ is radically different from C. It has classes (with plain constructors, copy constructors, destructors, visibility rules), exceptions, templates, operator overloading, move, RAII, stuff like constexpr, to name a few.

Due to the above, stuff like `{ Foo * c = a + b; }` may have a completely different interpretation in C++ than in C.

Few people would write C++ as if it were C. They would then rather write C instead.

A C++ compiler happens to include a C compiler, and allows to easily mix C++ and C code. This is just a convenience; the Zig compiler also includes a C compiler and allows to easily mix in C code, but nobody would mistake Zig for C.

Saying "C/C++" is like saying "car/aircraft", just because an F-150 and a Cessna 182 happen to include a piston engine and a seat behind it.