intArray class problem!

I have to write an intArray class with different operators overloaded for it,
The problem is that how i can overload operator - for it,here is the class code (partial)

Code:

---

class intArray
{
        int *ptr;
        int size;
public:
        intArray(int=0);
        intArray(int*,int=0);
        intArray& operator=(const intArray&);
        intArray operator-(intArray&);
        ~intArray(){delete [] ptr;}
        void Print()const;
};
intArray intArray::intArray(int s=0)
{
        size=s;
        ptr=new int[size];
}
intArray intArray::operator-(intArray& rhs)
{
        intArray temp(size);
        .        //perform operations on temp and rhs original lhs array
        .
        .
        return temp;                //causing problem
}

---

in the main i have to use code similar to this

Code:

---

int main()
{
        int p[]={2,3};
        intArray a1(p,2);
        intArray a2(2);
        (a1-a2).Print();        //print result of a1 - a2
        return 0;
}

---

and it is the problem ,when operator - is called it returns the temporary array
but since its scope is only limited to operator - function,
the ~intArray() destructor is called and it frees up the memory which is being used by
"temp"
,so how i can convert it in such a way that function call (a1-a2).Print()
should be valid...

i have tried to do it by removing ~intArray() destructor,it works fine but
what about the dynamic memory allocated by it????

Hmm I see the problem. I´m not sure of this but I give it a try. When you are returing a value by value (like in your case) it creates a temporary object to the function that invoked that function (hope you get it). And if your a returing an user-defined object the copy constructor is invoked. In other words I think your problem lies that you don´t have a copy-construtor (don´t realy on default copy-construtor). Create an approriate copy-constructor and tell me if it works.

i have written a copy constructor
but it does not seem to work,without it junk values was being printed but with a copy constructor,it does not print anything after return and returning a run time error,here is the copy constructor

Code:

---

intArray::intArray(intArray& t)
{
        size=t.size;
        delete [] ptr;
        ptr=new int[t.size];
        for(int i=0;i<t.size;i++)
        {
                *(ptr+i)=*(t.ptr+i);
        }
}

---

Quote:

---

Originally posted by nag

Code:

---

intArray::intArray(intArray& t)
{
        size=t.size;
        delete [] ptr;
        ptr=new int[t.size];
        for(int i=0;i<t.size;i++)
        {
                *(ptr+i)=*(t.ptr+i);
        }
}

---

---

because you
delete [] ptr
in your example, but ptr is just some garbage value (remember it's an unitialized member, you're in a constructor).