How does access checking work in type alias templates?

Consider this code:

struct A
{
    template <typename T>
    using type = decltype(&T::foo);
};

class B
{
    void foo() {}
    friend A;
};

int main()
{
    A::type<B> x;
}

> Run on gcc.godbolt.org <

It compiles on GCC and MSVC, but makes Clang complain: error: 'foo' is a private member of 'B'.

Is it a Clang bug? How can I work around this issue?

Edit: The duplicate doesn't provide a workaround, so here's one.

struct A
{
    template <typename T>
    static decltype(&T::foo) helper();

    template <typename T>
    using type = decltype(helper<T>());
};

class B
{
    void foo() {}
    friend A;
};

int main()
{
    A::type<B> x;
}