Returning pointer to template function instantiation from constexpr function

Question

I've been digging through cppreference, but I cannot figure out why the code below does not compile. Can anybody enlighten me?

template<typename T, T a> void g();
typedef void(*Func)();
Func f;

template<typename T>
constexpr Func get(T a)
{
   return g<T, a>;
}

void set()
{
   f = get(1);
}

I'm compiling with something like

g++ -c -Wall -Werror -std=gnu++11