struct A { };

template <int>
struct Parent { };

template <int N>
constexpr int operator*(A, Parent<N>*) { return N; }

template <class T>
using ptr = T*;

template <int>
struct Other { };

template <int N>
struct Kid: Parent<N> {
    static Other<A{} * ptr<Kid>{}> o;
};

int main() {
    Kid<2>{};
}

prog.cc:7:15: note: candidate template ignored: could not match 'Parent' against 'Kid'
constexpr int operator*(A, Parent<N>*) { return N; }

struct A { };

template <int>
struct Parent { };

template <int N>
constexpr int operator*(A, Parent<N>*) { return N; }

template <class T>
using ptr = T*;

template <int>
struct Other { };

template <int N>
struct Kid: Parent<N> {
    static constexpr int s = A{} * ptr<Kid>{};
};

int main() {
    Other<Kid<2>::s>{};
}