VC++ Bug with Decltype or Undefined Behavior?

I have this code:

#include <iostream>
#include <type_traits>
using namespace std;
template<typename T>
T f2(T&&t) {
    return t;
}
int rr(int i) {
    return 40*i;
}
int main()
{
  cout << is_function< remove_reference<decltype(f2(rr))>::type>::value << endl;
}

When compiled with VC++2015, i got this error:

error C2893: Failed to specialize function template 'T f2(T &&)'

The main issue is with using decltype() on the expression f2(rr). Note that f2's parameter is T&&. This is called Universal Reference by Scott Meyers: universal reference. I am expecting f2(rr) yields an expression whose type is a function reference. In GCC, it runs normally and returns true, and hence, confirms that f2(rr) is a function reference.

Is this simply a bug with VC++2015 rather than undefined behavior when the univeral reference is used with a function name?

EDIT: This works correctly in VC++2015:

int main()
{
  cout << f2(rr)(10) <<endl;
}

result:

400