Thread: ADT

The constructor for winery, node, or both is taking in values which don't match their declarations and definitions.

This example should have the same error message:

Code:

class Test
{
     int x;
};

int main()
{
     Test test(0);
     return 0;
}

can you explain a little further, Im not seeing what you are.

You are trying to create a node using a constructor that does not take an argument:

Code:

node * newNode = new node;

the only constructor you've provided is one which takes a winery object:

Code:

node(const winery& winery);		// constructor

Get it?

You are not using a constructor to build a linked list, so it's going to remain new to you (especially since such a thing doesn't really make sense). You are using the insert method of a list object to build a list. But you do need to build the nodes, and in order to do that your node requires a winery -- look at where rags_to_riches pointed out your node constructor. So whenever you call a new node, you need to pass the winery in. You are aware you can do something like this, right:

Code:

int *foo;
foo = new int(5);

where we call the int constructor with a parameter?

tabstop, your talking about doing this right?

Code:

node* newNode = new node(winery);

what do i need to do in the node constructor then?
God im confused.

Originally Posted by mrsirpoopsalot

tabstop, your talking about doing this right?

Code:

node* newNode = new node(winery);

what do i need to do in the node constructor then?
God im confused.

Why should you need to do anything more than what's already there? The point being, you had to give the winery to the constructor when you call it so that it could use it.

I am still getting this error:
error C2512: 'winery' : no appropriate default constructor available

in reference to

Code:

list::node::node(const winery &winery)
{

//item = winery;
//nextByName = NULL;
//nextByRating = NULL;


}

Code:

private:
	struct node
	{
		node(const winery& winery);		// constructor
		winery item;
		node * nextByName;
		node * nextByRating;
	};

	node * headByName;
	node * headByRating;
};

Same song, second verse:

Code:

winery item;

Your constructor for node is going to have to construct this object, and there are no default constructors. At this point it's getting annoying trying to remember which winery is the type and which winery is the variable, which is why you shouldn't do that. Consequently your node constructor should call the winery constructor, something like this:

Code:

node(const winery &incoming) : item(incoming)
{
    /* set some pointers
}

Originally Posted by mrsirpoopsalot

I am still getting this error:
error C2512: 'winery' : no appropriate default constructor available

Let's go over, again, exactly what your problem is. I didn't point out exactly where your problem is in my previous post, but others have told you pretty much exactly where it is. Let's go over the concept of a constructor and a function, and then you'll see where you went wrong.

You are no doubt aware of how a function works. You declare it, define it (possibly in the same place), and can pass values to it, based on how it is declared. A constructor is merely a special function. Just like regular functions, constructors can be overloaded. In your case, you need a second constructor, one that takes no arguments. Why? Well let's take at these lines:

Code:

node * nextByName;
node * nextByRating;

Let's then take a look at this line:

Code:

node(const winery& winery);		// constructor

I hope you notice the type mismatch between the constructor and the nodes. Your constructor basically says that in order to create a node, you must pass it a winery object. The two nodes within your function are not being passed a winery object, and so cannot be built. That is unless you declare a second constructor, like this:

Code:

node();		// constructor

Thank you for all your help! sorry i haven't seen what you guys have been talking about.
I just didnt see why the constructor would need the winery object.

The bad part is we are not suppose to change some of the files.
and i would assume thats where the default node constructor would go

Code:

// make NO CHANGES to this file

#ifndef _LIST_
#define _LIST_

#include <ostream>
#include "winery.h"

using namespace std;
//const int SIZE = 100;

class list
{
public:
	list(void);				// constructor
	virtual ~list(void);	// destructor
	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:
	struct node
	{
		node(const winery& winery);		// constructor
		winery item;
		node * nextByName;
		node * nextByRating;
	};

	node * headByName;
	node * headByRating;
};

#endif // _LIST_

What i did come up with was this.. However, i am not sure if it is right.
I get no compile errors..

Code:

list::node::node(const winery &winery): item(winery.getName(), winery.getLocation(), winery.getAcres(), winery.getRating())

{

so, obviously i still cant create a node. Again, i apologize if i am not getting this fast enough. Please be patient with me..

The teacher is not teaching us why we have to do it this way or even how to do it, i am basically on me own. Thank you guys for helping me.

So i should be able to do this then?
node* newNode = new node(winery); // crashes
but what do i have to do within the constructor?

Sorry if i havent got what you guys are saying!!!!!!

It wouldn't surprise me that your instructor hasn't mentioned how to make exactly this program work; I wouldn't have either. You have the information about what constructors are, how function calls work, what's needed to construct an object in C++, etc. You should then apply that information to the current situation. None of us here are reading off a sheet titled "How the Winery Problem Works"; we're taking the information at hand and our knowledge of the language and using the tools at our disposal to solve a problem.

You need to sit back, and look at your problem. How of much what you pasted in here was given and how much of it was yours I'm not sure. But for each class you have to write, you need to ask yourself: what members are in this class; how am I going to get data into these members, and what can I do with these members once they're initialized.

It might also help to first approach the problem "on your own terms", that is, write a program that does exactly what this assigment calls for, but using whatever method you're comfortable with. Once you have it working properly, compare the two and slowly build in the functionality into the required format, little by little.

Along the way, it might be a good idea to get better aquainted with the language by reading as many books/tutorials as possible.