Question

When overloading the = operator, should one make the contents of one object equal to the contents of the other object OR do you make the pointer of the object point to the same object?

Reading back on the question it seems that the contents should be copied and not the pointers. But I just can’t figure it out, So I would be grateful if someone would explain what I should do, I know how to do both, I’m just not sure which one to choose.

class IntObject
{
private:
    int *pi_One;

public:

    IntObject(void);

    IntObject::IntObject(int const &i_one);

    ~IntObject(void);

    IntObject & operator=(const IntObject&);

};

IntObject::IntObject()
{
    pi_One = new int(0); 
}

IntObject::IntObject(int const &i_one)
{
    pi_One = new int(i_one); 
}

IntObject::~IntObject(void)
{
    delete pi_One;
}

IntObject & IntObject::operator=(const IntObject& c) {
//This copies the pointer to the ints
    this->pi_One = c.pi_One;

    return *this;  
}

Answer 1

It depends on what semantics you want to have in your type. If you want value semantics, then copy the contents (deep copy, as is the case in std::vector), if you want reference semantics (shallow copy, as in std::shared_ptr)