overload insert operator problem

Code:

---


#include <iostream.h>
//using namespace std;


class SimpleClass
{
public:
        SimpleClass();
        SimpleClass(SimpleClass &);
        ~SimpleClass();
        friend ostream & operator<<(ostream &,SimpleClass&);
        int GetData();
        void SetData(int);
        void testfunction(SimpleClass);
private:
        int itsData;
};

SimpleClass::SimpleClass():itsData(0){cout<<"Default constructor called!"<<endl;}
SimpleClass::SimpleClass(SimpleClass &rhs){cout<<"Copy constructor called!"<<endl;}
SimpleClass::~SimpleClass(){cout<<"Destructor called!"<<endl;}

int SimpleClass::GetData(){return itsData;}
 
ostream& operator<<(ostream &o, SimpleClass &rhs)
{
        o<<rhs.GetData();
        return o;
}

void SimpleClass::testfunction(SimpleClass obj)
{       
        //why at this place default constructor is not called
        obj.SetData(2);
}//Destructor is called when obj goes out of scope

void SimpleClass::SetData(int i)
{
        itsData=i;
}

int main()
{
        SimpleClass obj; //this will cause message "Default constructor called"
        cout<<obj<<endl;
        obj.testfunction(obj);
        return 0;
}

---

If I put on first two lines:
#include <iostream>
using namespace std;
I get following compiler error:
c:\program files\microsoft visual studio\myprojects\konstruktor\konstruktor.cpp(45) : error C2593: 'operator <<' is ambiguous
Error executing cl.exe.

but if I put
#include <iostream.h> it works fine
why is this happening and how to fix it

>> //why at this place default constructor is not called
Because the copy constructor is called to make a copy of obj from main() into the obj from testfunction() parameter. If you don't want to make a copy, make the parameter a reference paramenter.

>> I get following compiler error:
Well I don't get that error using VC++ 6.0, but you could try:

Code:

---

friend ostream & operator<<(ostream &,const SimpleClass&);

---

gg

My guess is that it is the MSVC friend bug. Try to download the approiate patch and the problem should be solved. If I remember it correctly you can avoid the bug by making

Code:

---

friend ostream & operator<<(ostream &,SimpleClass&);

---

inline like this

Code:

---

class SimpleClass
{
public:
        SimpleClass();
        SimpleClass(SimpleClass &);
        ~SimpleClass();
        friend ostream & operator<<(ostream &o,SimpleClass &rhs)
{
        o<<rhs.GetData();
        return o;
}
        int GetData();
        void SetData(int);
        void testfunction(SimpleClass);
private:
        int itsData;
};

---

and remove the previous implementation. Skip this codesnippet

Code:

---

ostream& operator<<(ostream &o, SimpleClass &rhs)
{
        o<<rhs.GetData();
        return o;
}

---

You can download service pack 5 for 6.0 here.

gg