intArray class problem!

[nag]

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)

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

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????

[ripper079]

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.

[nag]

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

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);
	}
}

[Polymorphic OOP]

Originally posted by nag

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).