I have searched for an answer to this question and tried the solutions suggested. Namely #pragma once and #ifndef/#endif. They haven't worked for me.
The problem I'm having is that every single function in my code is being defined multiple times. I have used #pragma in an attempt to reduce header inclusion to a single time, and I as a general practice I always include the #ifndef/#endif in my header files. Neither fix works and I suspect it's due to the way the makefile is written, which is also included below.
This is the error output I'm receiving upon compiling:
BinaryNode.cpp:6:1: error: redefinition of ‘BinaryNode<ItemType>::BinaryNode()’
In file included from BinaryNode.h:35:0,
from BinaryNode.cpp:1:
BinaryNode.cpp:6:1: error: ‘BinaryNode<ItemType>::BinaryNode()’ previously declared here
BinaryNode.cpp:13:1: error: redefinition of ‘BinaryNode<ItemType>::BinaryNode(const ItemType&)’
In file included from BinaryNode.h:35:0,
from BinaryNode.cpp:1:
BinaryNode.cpp:13:1: error: ‘BinaryNode<ItemType>::BinaryNode(const ItemType&)’ previously declared here
BinaryNode.cpp:22:1: error: redefinition of ‘BinaryNode<ItemType>::BinaryNode(const ItemType&, BinaryNode<ItemType>*, BinaryNode<ItemType>*)’
In file included from BinaryNode.h:35:0,
from BinaryNode.cpp:1:
BinaryNode.cpp:22:1: error: ‘BinaryNode<ItemType>::BinaryNode(const ItemType&, BinaryNode<ItemType>*, BinaryNode<ItemType>*)’ previously declared here
BinaryNode.cpp:30:6: error: redefinition of ‘void BinaryNode<ItemType>::setItem(const ItemType&)’
In file included from BinaryNode.h:35:0,
from BinaryNode.cpp:1:
(And so forth, for every function defined in the implementation file below.)
Header file (Cannot be modified):
#ifndef _BINARY_NODE
#define _BINARY_NODE
template<typename ItemType>
class BinaryNode
{
private:
ItemType item; // Data portion
BinaryNode<ItemType>* leftChildPtr; // Pointer to left child
BinaryNode<ItemType>* rightChildPtr; // Pointer to right child
public:
BinaryNode();
BinaryNode(const ItemType& anItem);
BinaryNode(const ItemType& anItem,
BinaryNode<ItemType>* leftPtr,
BinaryNode<ItemType>* rightPtr);
void setItem(const ItemType& anItem);
ItemType getItem() const;
bool isLeaf() const;
BinaryNode<ItemType>* getLeftChildPtr() const;
BinaryNode<ItemType>* getRightChildPtr() const;
void setLeftChildPtr(BinaryNode<ItemType>* leftPtr);
void setRightChildPtr(BinaryNode<ItemType>* rightPtr);
}; // end BinaryNode
And here is my implementation file (CAN be modified):
#include "BinaryNode.h"
#include <stddef.h>
template<class ItemType>
BinaryNode<ItemType>::BinaryNode()
{
leftChildPtr = NULL;
rightChildPtr = NULL;
}
template<class ItemType>
BinaryNode<ItemType>::BinaryNode(const ItemType& anItem)
{
item = anItem;
leftChildPtr = NULL;
rightChildPtr = NULL;
}
template<class ItemType>
BinaryNode<ItemType>::BinaryNode(const ItemType& anItem, BinaryNode<ItemType>* leftPtr, BinaryNode<ItemType>* rightPtr)
{
item = anItem;
leftChildPtr = leftPtr;
rightChildPtr = rightPtr;
}
template<class ItemType>
void BinaryNode<ItemType>::setItem(const ItemType& anItem)
{
item = anItem;
}
template<class ItemType>
ItemType BinaryNode<ItemType>::getItem() const
{
return item;
}
template<class ItemType>
bool BinaryNode<ItemType>::isLeaf() const
{
return ((leftChildPtr == NULL) && (rightChildPtr == NULL));
}
template<class ItemType>
BinaryNode<ItemType>* BinaryNode<ItemType>::getLeftChildPtr() const
{
return leftChildPtr;
}
template<class ItemType>
BinaryNode<ItemType>* BinaryNode<ItemType>::getRightChildPtr() const
{
return rightChildPtr;
}
template<class ItemType>
void BinaryNode<ItemType>::setLeftChildPtr(BinaryNode<ItemType>* leftPtr)
{
leftChildPtr = leftPtr;
}
template<class ItemType>
void BinaryNode<ItemType>::setRightChildPtr(BinaryNode<ItemType>* rightPtr)
{
rightChildPtr = rightPtr;
}
Also, here is my makefile. I have a feeling this is where the problem is, but after an hour of reading makefiles aren't any more obvious to me.
lab10: main.o BinaryNode.o
cc -o lab10 main.o
main.o : main.cpp BinaryNode.h
cc -c main.cpp
BinaryNode.o: BinaryNode.cpp BinaryNode.h
cc -c BinaryNode.cpp
clean :
rm *.o *~
And my main.cpp, which is only there right now to make the compiler happy:
#include "BinaryNode.h"
int main(int argc, char* argv[])
{
};