assign variable to itself on declaration [duplicate]

Question

This code fails at runtime in the copy constructor.
But the compiler (MSVS2008) issues no warnings.

Could you explain (preferably cite the standard) whether this code is illegal or what?

I understand that A a = a; should never be written at the first place, but I am looking for a theoretical background.

 class A
 {
 public: 

    A()
    :p(new int)
    {
    }

    A(const A& rv)
    {
        p = new int(*rv.p);
    }

    ~A()
    {
        delete p;
    }


 private:

    int *p;
 };

 int main()
 {
    A a = a;
 }

Answer 1

Your code is not calling the standard constructor but the copy constructor, so you are accessing an uninitialized pointer.