Circular Double Linked List - Logic in Operator=
Hello folks, I am working ona a circular double linked list and trying to overload the operator= operand but I think my logic is false.
It takes in a linked list and inserts the data into the current linked list.
I believe this is not a deep copy
Code:template <class T> CList<T>& CList<T>::operator=(const CList<T> &a){ if(this!=&a){ if(a.curr_){ Node<T> *nn_ = a.curr_; do{ nn_ = nn_->next_; insert(nn_->data_); }while(nn_!=a.curr_); } } return *this; }
Usually the result of using operator= is that both sides would have the same value. What you are trying to do is append, which is more along the lines of what operator+= does.
If you want to make it a real operator=, then clear your current list before adding the other elements.
The only thing I see wrong with that code if it was for operator+= is that I think it skips the insertion of a.curr_. If it was an operator+= I wouldn't check for self-assignment either.
Any tips on how to do this?
I'm not sure what you mean. Those are the tips on how to do that. Is there something in particular that you'd like more information on?
How to remove every node of the list.
I came up with this code but I come up with an unhandled windows32 exception upon runtime.
It deletes the node pointed at by curr_Code:template <class T> bool CList<T>::remove(){ if(this->isempty()){ return false; } else if(!this->isempty()&&curr_){ Node<T> *prev_; Node<T> *next_; if(curr_->next_==curr_&&curr_->prev_==curr_){ delete curr_; curr_ = NULL; } else{ prev_ = curr_->prev_; next_ = curr_->next_; delete curr_; prev_->next_ = next_; next_->prev_ = prev_; curr_ = next_; return true; } } else return false; }
Last edited by INFERNO2K; 09-30-2006 at 10:03 AM.
I don't see anything particularly wrong with that remove function (except that if there is only one node in the list the function exits without returning a value). I assume you have a clear function that keeps calling it while it returns true, which also should be ok.
You'll have to find out more information on when, where and why the exception occurs. A debugger would be most helpful for that. You can also make a small test program that writes to cerr after each step if you can't use the debugger.
