#include <iostream>

template<typename T> struct A {};
template<typename T, typename U, typename V> void f(T&, const U&, V) { std::cout << "f1\n"; } //#1
template<typename T, typename U, typename V> void f(T&&, U&, A<V>) { std::cout << "f2\n"; } //#2

int main()
{
   int a = 7;
   const char b = 'a';
   A<int> c;
   f(a, b, c); //Should print 'f2'.
}