C++ preprocessor directive issue - c++

Question

I have a stream class with following functions :
void writeInt(int value); //old function
void writeInt(int value, char* lable); //new function
we've used the writeInt() old function in lot of places. without changing the existing usage
I tried to replace the old function with the new function using following:
#define writeInt(x) writeInt(x,#x)
but it still calls the old functions not the new functions!.
Update:(working test-case)
// IStream.h
#include <stdio.h>
class IWStream {
public:
IWStream(char* path);
virtual ~IWStream();
virtual void writeInt( int iValue, char* szlable= 0 );
private:
FILE* _file;
};
//DataObject.h
class DataObject {
public:
DataObject(int value);
virtual ~DataObject(){};
void writeData(IWStream *stream);
private:
int _value;
};
//DataObject.cpp
#include "DataObject.h"
#include "IStream.h"
#define writeInt(x) writeInt(x,#x)
DataObject::DataObject(int value)
{
_value = value;
}
void DataObject::writeData(IWStream *stream)
{
stream->writeInt(_value);
}
//main.cpp
int main(){
IWStream stream("D://test.txt");
DataObject data(10);
data.writeData(&stream);
return 0;
}