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 T &c) { return A(b) << C<T>(c); }
int main() {
B b;
b << 1.2;
return 0;
}