Assertion Error and Ostream problem

[snazziosity]

I'm having two problems with my code.

First problem: I'm trying to get it to print correctly, but I can't figure out the best way to call the Winery class' << overload.

Here's the printing code in Winery.cpp:

void Winery::displayColumnHeadings(ostream& out)
{
	// print out column headings for lists of wineries, as specified by lab1output.txt
	out << setw(26) << "name" << setw(19) << "location" << setw(6) << "acres" << setw(6)
		<< "rating" << endl << "----                      --------           ----- ------" << endl;
}

ostream& operator<<(ostream& out, Winery *w)
{
	// print out a winery, as specified by lab1output.txt

	out << setw(26) << w->name << setw(19) << w->location << setw(6) << w->acres << setw(6)
		<< w->rating << endl;
	return out;
}

This is how I'm calling it:

void List::displayByName(ostream& out) const
{
	Node*		curr;
	Winery*     winptr;

	winptr = & ;

	for(curr = headByName; curr; curr = curr->nextByName)
		out << '\t' << curr->item << endl;
}

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Second problem: The program compiles without errors in VisualStudio, but the program won't run all the way through without an assertion error. I've been trying to figure this out for a while, but I have no idea what this even means. Will somebody please help?

Here's the function that I think may be the culprit:

void List::insert(const Winery& winery)
{
	Node * prev = NULL;
	Node * curr = headByName; 

	//traverse to find the position to insert
	while (curr!=NULL && curr->item.getName() < winery.getName())
	{
		prev = curr;
		curr = curr->nextByName;
	}

	//the data already exists
	if(curr && curr->item.getName() == winery.getName());
		//return false;
	//insert the data here
	else
	{
		//create new node to contain the data
		Node * newNode = new Node(winery);
		newNode->item = winery;
		newNode->nextByName = NULL;
		newNode->nextByRating = NULL;

		//link the newNode into the linked list
		newNode->nextByName = curr;
		if(prev == NULL)
			headByName = newNode;
		else
			prev->nextByName = newNode;
		//size++;
		//return true;
		curr = headByRating;
		while (curr!=NULL && curr->item.getRating() < winery.getRating())
		{
			prev = curr;
			curr = curr->nextByRating;
		}
		//link the newNode into the linked list
		newNode->nextByRating = curr;
		if(prev == NULL)
			headByRating = newNode;
		else
			prev->nextByRating = newNode;
	}
}

Here's list.h

class List
{
public:
	List(void);				// constructor
	virtual ~List(void);	// destructor

	// Print out the wineries in alphabetical order by name,
	// by calling winery's operator<< for each winery.
	void displayByName(ostream& out) const;

	void displayByRating(ostream& out) const;

	void insert(const Winery& winery);

	Winery * const find(const char * const name) const;

	bool remove(const char * const name);

private:
	// defines each node in the doubly-threaded linked list.
	struct Node
	{
		Node(const Winery& winery);		// constructor
		Winery item;
		Node *nextByName;
		Node *nextByRating;
	};

	Node *headByName;
	Node *headByRating;
};

Thank you!