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POIs this a deep copy and properly implemented = operator for a C++ Linked List?
 

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  1. POIs this a deep copy and properly implemented = operator for a C++ Linked List?
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    <p>I'm running into some bugs now that I'm trying to use the doubly linked list class that I made. My implementation of the = operator looks like the following:</p> <pre><code>template &lt;typename T&gt; Dlist&lt;T&gt;&amp; Dlist&lt;T&gt;::operator=(const Dlist &amp;l) { copyAll(l); return *this; } template &lt;typename T&gt; void Dlist&lt;T&gt;::copyAll(const Dlist &amp;l) { node *copyList = new node; copyList = l.first; while(copyList){ insertFront(copyList.first-&gt;o); copyList = copyList-&gt;next; } delete copyList; } </code></pre> <p>Note that o is a pointer for the data in a node in the List.</p> <p>My intent is for copyAll to be a true deep copy. Is this not the case? Is there something wrong with my class method definitions here? I'm new to linked lists so help is much appreciated!</p> <p>EDIT: specifically the issue I'm having is when I make a List and fill it, then make a new list and set it equal to the first, anytime I do something to the second list, it also alters the first list. </p> <p>EDIT2: Here's the class itself. I'm not allowed to add any other member functions:</p> <pre><code>template &lt;typename T&gt; class Dlist { public: // Operational methods bool isEmpty(); // EFFECTS: returns true if list is empty, false otherwise void insertFront(T *o); // MODIFIES this // EFFECTS inserts o at the front of the list void insertBack(T *o); // MODIFIES this // EFFECTS inserts o at the back of the list T *removeFront(); // MODIFIES this // EFFECTS removes and returns first object from non-empty list // throws an instance of emptyList if empty T *removeBack(); // MODIFIES this // EFFECTS removes and returns last object from non-empty list // throws an instance of emptyList if empty // Maintenance methods Dlist(); // ctor Dlist(const Dlist &amp;l); // copy ctor Dlist &amp;operator=(const Dlist &amp;l); // assignment ~Dlist(); // dtor private: // A private type struct node { node *next; node *prev; T *o; }; node *first; // The pointer to the 1st node (NULL if none) node *last; // The pointer to the 2nd node (NULL if none) void makeEmpty(); // EFFECT: called by constructors/operator= to establish empty // list invariant void removeAll(); // EFFECT: called by destructor/operator= to remove and destroy // all list elements void copyAll(const Dlist &amp;l); // EFFECT: called by copy constructor/operator= to copy elements // from a source instance l to this instance }; </code></pre>
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    1. USSlims
    1. USSlims
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      1. POIs this a deep copy and properly implemented = operator for a C++ Linked List?
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      1. VTUpMod
    2. VO
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      1. POIs this a deep copy and properly implemented = operator for a C++ Linked List?
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      1. VTUpMod
    1. COI don't think that code can compile, you're using `copyList` both as a pointer (->next) and as a reference (.first). The delete at the end doesn't make sense, `copyList` should always be null at that point.
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      1. POIs this a deep copy and properly implemented = operator for a C++ Linked List?
      1. USMat
    2. COIt definitely compiles, but it doesn't do what it's supposed to.
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      1. POIs this a deep copy and properly implemented = operator for a C++ Linked List?
      1. USSlims
 

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