与它所属的类相同类型的对象数组会创建无限实例吗？

Question

Sorry for the awkward wording of the question but I'm not sure how to describe it better in words so I'll try an example

struct A {
    A* a;
    A() {a = new A[2];}
    ~A() {delete[] a;}
}

int main() {
    A aa;
}

Once aa gets constructed, the *a internal to struct A will be allocated an array of two A objects. But it appears to me that each of those objects will, in turn, create an array of A objects of their own as a result of the default constructor, and on and on in a seemingly endless cycle. Am I correct in thinking this?

Answer 1

Am I correct in thinking this?

Yes. The constructor is called recursively, and you'll probably run out of dynamic storage or overflowing the call stack at some point.

Answer 2

Yes, you are absolutely right. Your code effectively embeds an array of objects inside itself. Essentially, you are making this impossible struct :

struct A {
    A a[2]; // Impossible
};

Your code bypasses compiler's check for by using pointers, so the code crashes at runtime due to infinite recursion.

If you would like to make A that refers to two A s optionally, make an array of two pointers.