C++ Inheritance of abstract reference members for polymorphism

Question

I have an abstract class with N protected members:

class Something {
protected:
    UINT someVal;
    std::vector<SomeType> g_MyVec;
    // some virtual abstract methods ...
public:
    UINT getSomeVal() { return someVal; }
    std::vector<SomeType> GetVec() { return g_MyVec; }
}

class SubClass : public Something {
public:
    SubClass() { // no members in this class, all inherited from super
        someVal = 5; // this sticks
        g_myVec = { .. correct initialization }; // this doesn't stick
    }
}

The client of this code does:

Something* s = &SubClass();
s->getSomeVal(); // OK, has 5 in it.
s->GetVec(); // Nada, it returns 0 size, nothing at all... WHY?!

Enlightenment is much appreciated.

Answer 1

You are taking an address of the temporary. It's a UB and incorrect code. Subclass gets destroyed along with the vector after the ;

Correct way to do this would be (Assuming no C++11):

Something* s = new Subclass();
s->getSomeVal(); // OK, has 5 in it.
s->GetVec(); 
delete s;