Non-replacement of types

[Demir]

class A;
class B
{
    public:
        B (A *p):y(p) {}
        ~B() {delete y;} 
        operator A const& () const {return *y;}
        operator A& () {return *y;}
    private:
        A *y;
};
class A
{
    public:
        A(int ax):x(ax) {}
        A* Clone() const 
        {
            return new A(x);
        } 
        B operator + (A const &v2) const
        {
            A *pv=v2.Clone();
            pv->x+=x;
            return B(pv);
        }
        friend ostream& operator << (ostream &os, A const &v)
        {
            os << x;
            return os; 
        }
    protected:
        int x;
};
int main()
{
    A v(4),v1(5);
    cout << v+v1; // <----------
}

Why doesn't this instruction work and why does it appear? ?

[Warning] possible problem detected in invocation of delete operator:

[enabled by default]

[baileigh]

At the point where the compilation takes place ~B()I can't see. Total Definition A♪ Therefore, the compiler cannot determine exactly what he should do when it comes to delete♪

Try to split the project into parts: class definitions separately, implementation separately. So you can compil a destructor. B in .cpp, insert header with complete definition A♪

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With regard to the second part, I've got a gcc on it if I take it. friend ostream& operator << outside the class: http://ideone.com/SV56y2