C++ get private member

#include <iostream>

template<class M>
struct public_cast {
    static inline M m{};
};
template<auto M>
struct access {
    static const inline auto m = public_cast<decltype(M)>::m = M;
};

class C {
private:
    int x = 42;
};
template struct access<&C::x>;

int main() {
    std::cout << C{}.*public_cast<int C::*>::m;
}