Does C++ replace built-in operators with function calls?

Question

I was recently reading about operator overloading in C++. So, I was wondering whether the built-in operators are replaced by function calls behind the scenes.

For example, Is a + b(a and b are int types) replaced by a.operator+(b)? Or the compiler does something different?

Answer 1

There is no int::operator+. Whether the compiler chooses to compile a + b directly to assembly (likely) or replace it with some internal function like int __add_ints(int, int) (unlikely) is an implementation detail.