Copy contents of a unique pointer array in the copy constructor

Question

My class contains a unique pointer to an array. When the copy constructor is called, I want the class to create its own unique pointer array and just copy the contents of the old unique pointer array. I keep getting errors about converting from a const value, and I'm not sure how to get around it.

My pointer is declared under private like this:

std::unique_ptr<Manager[]> managers;

I planned to just loop through the array and copy manually, so I made this copy constructor:

Restaurant::Restaurant(const Restaurant &_r)
{
    Manager *_managers = _r.managers;
    for (int i = 0; i < MAX_MANAGERS; i++)
    {
        managers.get()[i] = _managers[i];
    }
}

It gives the const convert error on this line:

Manager *_managers = _r.managers;

I just want to make a deep copy. How can I go about it to make this work?

Answer 1

The reason that it won't compile is that _r.managers is of type std::unique_ptr<Manager[]>, but you want to initialize a raw pointer with this.

just change it to:

Restaurant::Restaurant(const Restaurant &_r)
{
    for (int i = 0; i < MAX_MANAGERS; i++)
    {
        managers.get()[i] = _r.managers.get()[i];
    }
}

or first take a smart pointer's data (which is an array)

Manager *_managers = _r.managers.get();

and then you can use it as was before:

for (int i = 0; i < MAX_MANAGERS; i++) {
        managers.get()[i] = _managers[i];
}