Passing template type parameter as a type of template non-type parameter

Just curious. According to C++17 and higher we can use an "auto" placeholder for non-type template parameters:

template<typename A, auto B>
class C {
public:
    A foo() { return B; }
};

But can we pass instead of "auto" template type parameter defined at left?

example.cpp

template<typename A, A B>
class C {
public:
    A foo() { return B; }
};

int main()
{
    C<int, 5> c;
    std::cout << c.foo() << std::endl;

    return 0;
}

Well in practice we can, and clang with -std=c++11 allows to do that.

$ g++ -std=c++11 example.cpp
$ ./a.out
5

But what about standard? I didn't find any explicit rule. Thanks!