Is there exception to rule that if address can be find out using & it's lvalue?

Question

Is there any exception to rule that if I can find address using & it's l-value otherwise r-value?

For example,

int i;

&i will give address of i, but I cannot take address of (i + 5), unless I is pointer or array.

Regards

Answer 1

The most obvious exception is overloading the prefix & operator for your own type:

#include <iostream>

struct X
{
    X* operator&()
    {
        return this;
    }
};

int main()
{
    std::cout << &X() << '\n';
}

This prints the address of the temporary object, which happens to be 0x7fff76012d9f when I ran it.