I’m trying to create a constant function that takes in a size int as a template parameter and returns an array that size with each index filled with its respective power of 2.

 template <int sz>
consteval int* conflagtab() {
    int ar[sz] = {};
    for (unsigned int i = 0; i < sz - 1; i++) {
        ar[i] = conflag(i);
    }
    return ar;
}

However when I am trying to use it I get the error “call to consteval function “conflagtab<sz>() [with sz=31]” did not produce a valid constant expression”.

I tried putting it in global namespace to see if that had a change but it had no difference. I’m expecting it to just return a pointer to the array.