#include <memory>

class C;
std::unique_ptr<C> pC;

C& f() {
    if (!pC) throw 0; // OK, even though C is incomplete
    return *pC;         // OK, even though C is incomplete
}

template <class T>
class X
{
    T t;
};

std::unique_ptr<X<C>> pX;

typename std::add_lvalue_reference<X<C>>::type DoSomeStuff() // exact copy of operator*
{
    return (*pX.get());
}

void g() {
    if ((bool)pX) return;
}

class C {};

int main()
{
    auto z = DoSomeStuff();
}