Question

Is it possible to overload the operator new() to have a different return value than void*?

I have two structures:

One structure (A) just holds data and what not.

The second structure (B) is built to act like a pointer to the first:

struct A;

struct B
{

private:

    A* ptr;

public:

    A& operator*() { return (*ptr); };
    A& operator->() { return (*ptr); };

};


struct A
{
    int data;

    B operator&() { B ret;  ret.ptr = this; return ret; };
};

The idea is as simple as this.
I don’t want any external classes handling pointers to A, not directly.

However, I do want them to be able to create instances of A. Is there a way to override A’s new operator to return an instance of B? Nevermind right now the safety concerns, and handling delete, this is just a simple, reduced example to explain my problem.

Answer 1

Operator new is only responsible to allocate memory for the class and then C++ internally call constructor to initialize that memory, so if you want to override something to new A result in a B, then you should override C++!

Instead you may have:

struct A {
private
    friend struct B;
    A() {}
};
struct B {
    static B new_A() {return B(new A());}
}