Overloading unary operator &

Question

Let's consider a class with overloaded unary operator & (Address-of). Let it be class A

template <class C>
class A
{
public:
    C * operator &()
    {
        return &data;
    }
    //...
private:
    C data;
}

Now I want to pass to some function a pointer of type A to fill its data. Let us call it f

void f(A * auto_containter)
{
    //...
}

But it is clear why the code bellow wouldn't work (even wouldn't compile). It is because the overloaded operator is called.

A a;
f(&a);

The question is following:

Is there any syntax to pass address of a to f? If no, then for me it is very strange why it is allowed to overload unary operator &, because it makes code more buggy and difficult to understand. Or there are some other reasons?

Answer 1

Is there any syntax to pass address of a to f?

Yes, there's ugly syntax:

f( reinterpret_cast<A*>( &reinterpret_cast<char&>(a) ) );

boost::addressof is a nice and generic wrapper around it.

Answer 2

Use std::addressof function(or boost::addressof pre C++11). In any case, overloading unary & is highly dubious. Why do it instead of having a named function that returns the address of your data?