Как Можно перегрузить Оператор ==, если необходимо проверить указатель на nullptr

Навскидку пачка решений...

class Pointer1
{
public:
    void* ptr = nullptr;
};
class Pointer2
{
public:
    void* getptr() const { return ptr; }
private:
    void* ptr = nullptr;
};
class Pointer3
{
public:
    operator const void*() const { return ptr; }
private:
    void* ptr = nullptr;
};
class Pointer4
{
public:
    bool operator ==(const void * p) const { return ptr == p; }
private:
    void* ptr = nullptr;
};
class Pointer5
{
public:
    bool is_null() const { return ptr == nullptr; }
private:
    void* ptr = nullptr;
};

int main(int argc, const char * argv[])
{
    Pointer1 p1;
    if (p1.ptr == nullptr)       { cout << "p1 nullptr\n"; }
    Pointer2 p2;
    if (p2.getptr() == nullptr)  { cout << "p2 nullptr\n"; }
    Pointer3 p3;
    if (p3 == nullptr)           { cout << "p3 nullptr\n"; }
    Pointer4 p4;
    if (p4 == nullptr)           { cout << "p4 nullptr\n"; }
    Pointer5 p5;
    if (p5.is_null())            { cout << "p5 nullptr\n"; }
}