CRITIQUES WELCOME!

[eboyd]

oh shiza.
i addd the copy ctor for list like you pretty much had osdev64 and then all friggin hell broke loose.

if i let the compiler supply it, it seems fine. im lost.

which brings me to another question:

Do i want object declared like this:

Code: Select all

    dlist<int> list;
    dlist<int> list2 = list;
    dlist<int> list3(list2);

to behave the SAME AS this:

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    dlist<int> *list = new dlist<int>();
    dlist<int> *list2 = list;
    dlist<int> *list3(list2);

???????

It seems that the copy ctor is only envoked for objects like so:

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object myObject;
object another = myObject;

but not for:

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object *myObject = new object();
ojbject *another = myObject;

Somebody pleez explain what the frick is up with all this!?!

[frank]

Code: Select all

object myObject;
object another = myObject; 

is assigning the value of an object to an object so a copy would be necessary.

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object *myObject = new object();
ojbject *another = myObject;

is assigning the value of a pointer to a pointer. IE the only thing that should be copied is the address.

[eboyd]

I'm sorry. I guess I should have clarified my question.

Is the whole point of a copy constructor to STOP copied objects from referencing the same portion of memory?

So if myObj is a list from 1 - 10, and myObj2 is a copy of myObj, if myObj reverses its order, should myObj2 reverse as well?

[eboyd]

If what I'm assuming in my previous reply is true, than this is what I've come up with:

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dlist(const dlist& src) : head(new type(T())), tail(new type(T())) {

    clear();
    for(type* temp = (src.head)->next; temp != src.tail; temp =temp->next){
                
        pushb(temp->data);
    }
}

Look good?

[os64dev]

Ok, this will problably not hlp much but if you want to know what happens or need to happen then take a pencil and a piece of paper and draw the objects. trust me it will become very clear then.

[Solar]

Is the whole point of a copy constructor to STOP copied objects from referencing the same portion of memory?

The point of a copy constructor is to do what is "right" for the class in question. If the "right" thing goes beyond a shallow copy, you have to define a copy constructor of your own.

So if myObj is a list from 1 - 10, and myObj2 is a copy of myObj, if myObj reverses its order, should myObj2 reverse as well?

Up to you. I'd say it would be confusing, but your design requirements might be different. (You'd better document it in your headers, though.)