pointers and functions

[jay5965]

I've been having a bit of trouble with a piece of code, where I'm trying to call a function on the object being pointed to.

I'm afraid I may be using these incorrectly (I've been programming in c# for the last year or so, and am pretty rusty with c++ pointers) and I would welcome any help or insight anyone may be able to provide.

I will post three snippits of code, first a function which is giving me an issue (it is either telling me the left hand operand must be a struct/class/union, or if i use the deference operator it tells me that I have a syntax error '.') the second will the be trinaryGraph specification file and the third will be my node specification file. The code is a bit sloppy, It is meant to be used with a few other data containers not yet finished.


~Problem Code

template <class item>
Node<item> TrinaryGraph<item>::getNodeByPos(int x,int y,int z)//will be cleaned up by a data container containing 3 float values
{
	Node<item> *tempNode;
	tempNode=rootNode;

	if (x==0 && y==0 && z==0)
		return *rootNode;

	while(int iX=0 <= x)
	{
		if (tempNode.getLeftNode()==NULL)
			return NULL;
		tempNode=tempNode.getLeftNode();
		iX++;
	}
	
	while(int iY=0 <= y)
	{
		if (tempNode.getDownNode()==NULL)
			return NULL;
		tempNode=tempNode.getDownNode();
		iY++;
	}


	while(int iZ=0 <= z)
	{
		if (tempNode.getRightNode()==NULL)
			return NULL;
		tempNode=tempNode.getRightNode();
		iZ++;
	}

	return tempNode;

}

~TrinaryGraph Specification

template <class item>
class TrinaryGraph
{
public:

	///////CONSTRUCTORS///////

	TrinaryGraph(int xDim,int yDim,int Zdim, float step=1);

	~TrinaryGraph();


	/////MODIFICATION MEMBER FUNCTIONS/////////

	Node<item> getNodeByPos(int x,int y,int z);
	void createGraph(Node<item> current,int x=0,int y=0,int z=0);


	//data to fill must be hardcoded at this time
	void fillGraphFaces(int x=0,int y=0,int z=0);
	
	void fillGraph(Node<item> currentNode);
	void fillNodeAtLocation(int x,int y,int z);


	void swap(Node<item> first,Node<item> second);
	void swap(int x1,int y1, int z1, int x2, int y2, int z2);


	///TODO: faux random-access, matching(recursively)
private:
	struct dims
	{
		int x,y,z;
	};

	dims dimensions;

	Node<item>* rootNode;

	void fillGraphFaces(Node<item> currentNode, int x,int y,int z);

};

~Node specification

template <class item>
class Node
{
public:

	/////CONSTRUCTORS//////
	Node();
	Node(item idata);

	~Node();

	//MODIFICATION MEMBER FUNCTIONS///
	void setData(item data);

	void setLeftNode(Node<item> newNode);
	void setDownNode(Node<item> newNode);
	void setRightNode(Node<item> newNode);

	void createLeftNode(item idata);
	void createDownNode(item idata);
	void createRightNode(item idata);

	void createLeftNode( );
	void createDownNode( );
	void createRightNode( );

	void operator = (Node<item> source);
	void Node<item>::operator == (Node<item> source);

	//CONSTANT MEMBER FUNCTIONS//
	item getData() const;
	Node<item> getLeftNode() const;
	Node<item> getDownNode() const;
	Node<item> getRightNode() const;



private:
	item data;
	Node<item>* leftNode;
	Node<item>*downNode;
	Node<item>* rightNode;
	

};

I thank you for your time.

[jnmacd]

You declare tempNode as a pointer and to access it you use ->
However, you are

tempNode=tempNode.getLeftNode();

getLeftNode() does not return a pointer according to your Node specification, thats why you are getting an error. If you change it to

tempNode=&tempNode->getLeftNode();

It will compile, but this is probably not what you want.
Generally when dealing with nodes, everything is pointers.

[jay5965]

wonderful, that would most likely be my oversight, thank you very much. Ill try changing that first thing in the morning.