Why do these variables need to be outside the function?

Question

C++ / C#

I'm reading C++ Primer by Stenli Lippman.
The section on constexpr provides such an example.

Please explain why the variables i and j should be taken out of functions?
Although in practice everything works even if the variable i cannot be taken out.

Answer 1

Works, but turns into a regular const. And that's exactly what it does in the body of the function, because the actual dereference happens.