Перегрузка оператора =

const int& int_array::operator= (const int_array& in)
{
    size = in.size;
    capacity = in.capacity;
    mas = new int[capacity];
    for (int i = 0; i < size; ++i)
        mas[i] = in.mas[i];
    return *this->mas;
}

        int_array mas(5);
        for (int i = 0; i < mas.getSize(); ++i)
            mas[i] = rand()%10;
        print(mas);
        std::cout << "\n";
        int_array mas1 = mas;
        print(mas1);

int_array a, b, c;
a = b = c;

int_array& int_array::operator = (const int_array& in)
{
    if (this != &in)
    {
        //implement copy-and-swap idiom here
    }
 
    return *this;
}

int_array& int_array::operator= (const int_array& in)
{
    if (this != &in)
    {
        reserve(in.capacity);
        size = in.size;
        for (int i = 0; i < size; ++i)
            mas[i] = in[i];
    }
    return *this;
}

int_array& int_array::operator= (const int_array& in)
{
    if (this != &in)
    {
        int_array temp(in);
        temp.swap(*this);
    }
    return *this;
}
 
void int_array::swap(int_array& in) throw()
{
    std::swap(*this, in);
}

int_array& int_array::operator= (const int_array& in)
{
    if (this != &in)
    {
        int_array temp(in);
        temp.swap(*this);
    }
    return *this;
}
 
void int_array::swap(int_array& in)
{
    std::swap(mas, in.mas);
    std::swap(size, in.size);
    std::swap(capacity, in.capacity);
}