Implementing a constexpr strlen() is trivial and I looks just like it's from your ancient C textbook, save for the "constexpr" keyword. No goofyness involved.

Implementing a constexpr strlen() is trivial and I looks just like it's from your ancient C textbook, save for the "constexpr" keyword. No goofyness involved. Or you use what the C++ standard library has to offer. std::string_view(ptr).length(); or std::string(ptr).length(); or std::char_traits<char>::length(ptr); all work at compile time.