Is it possible that your function is returning a string rather than an array? That would explain the part of the error message: for 2nd argument std::string.

I'm marking this as resolved. I don't think it a kata issue.

Can you please describe what you did that led to this error? When I test everything it works fine. Also, other people have solved the kata in C++ without encountering this issue.

I'm sure most people who clicked best practice or clever were clicking it because that's funny, they're the kind of answers that are like: if it works, then it works.

Because this make sanse for those who learn c++.