how to overload operator= with pointers?

[exca]

Hi all,

I have written some classes in my code, and when I create object pointers of it, I want to assign one to another. I think I must write an operator= function to overload it. But I don't know how to do it with pointers. My class' constructor is:

ExpNode::ExpNode(){

	this->value=0;
	this->type=' '; // a number or operator? N or O?
	this->op=' '; // operator: + - / * (^)
	this->var=' '; // A, B, C etc.
	this->left=NULL;
	this->right=NULL;

}

and I want to do something like:

deque <ExpNode*> treedeque(exp.size()); // creating a deque with size of a string
	ExpNode *x=new ExpNode;
	treedeque[i]->value=value; // assigning an integer to the value field of ith element of treedeque
x=treedeque[5]; // assigning the 5th element of the deque to x 

Can you please help me?

[kempofighter]

Well you are copying the pointers which are integral values. Therefore the objects operator= isn't invoked when you copy only pointers. TO deep copy you'd do something like this.

*x = *(treeDeque[5]);

Of course that assumes that you have defined an assignment operator for the ExpNode class. Take a look at this article.
http://cplusplus.com/articles/jsmith1/

[exca]

Do I have to overload operator=, or does it automatically have one when I don't?

Because it says "First, you should understand that if you do not declare an
assignment operator, the compiler gives you one implicitly. The
implicit assignment operator does member-wise assignment of
each data member from the source object"

[kempofighter]

You may not need to define one for your nodes but I don't really know what your project does. The default does a shallow copy so the left and right pointers would be copied by the default and you'd end up with multiple nodes with the same left/right pointers. If you want those deep copied you have to write your own but I'm not sure why you need the copies so I can't make that decision for you.