class B {
public:
  int b;
};

template <class T> class C;

class A {
  int a;
public:
  A(const B &b) : a(b.b) {}
};

template <class T>
class C {
public:
  T c;
  C(const T &n) : c(n) {}
};

template <class T>
inline const A &operator << (const A &a, const C<T> &c) { return a; }

template <class T>
inline const A &operator << (const B &b, const C<T> &c) { return A(b) << c; }

int main() {
  B b;
  b << C<double>(1.2);
  return 0;
}