pure virtual function with body

[jinendrashankar]

Hi All,

1.Please check this code and its output which is working fine
while pure virtual functions( FUN1) prototype of Class CA is different
then Class CB Function (FUN1).

2. In Class CA pure virtual function ( FUN1) have body.

3. If i change my second pure virtual function(FUN2) prototype
class CA----> virtual int fun2()=0;
class CB---> void fun2(){ cout <<" fun of CB void::CB fun2() "<<endl;}

i am getting following error

$ CC -o CoVariance CoVariance.cpp
"CoVariance.cpp", line 24: Error: Virtual function CB::fun2() returns void, while CA::fun2() returns int.
1 Error(s) detected.

Can any one help me to find this dual behavior of code ?
#include<iostream>
using namespace std;

class CA
{
public:
CA()
{cout<<"CA::CA()"<<endl;}
virtual CA& fun1()=0;
virtual void fun2()=0;
virtual ~CA()
{cout<<"CA::~CA()"<<endl;}
};
void CA::fun2(){ cout <<"pure virtual fun of CA void::CA fun2() "<<endl;}

class CB:public CA
{
public:
CB()
{cout<<"CB::CB()"<<endl;}
~CB()
{cout<<"CB::~CB()"<<endl;}
CB& fun1(){ cout <<"CB fun1() "<<endl;return *this;}
void fun2(){ CA::fun2();}
};

int main()
{
CA *p = new CB;
p->fun1();
p->fun2();
delete p;
return (0);
}


OUTPUT:--
$ CC -o CoVariance CoVariance.cpp
$ ./CoVariance
CA::CA()
CB::CB()
CB fun1()
pure virtual fun of CA void::CA fun2()
CB::~CB()
CA::~CA()
$

[weaknessforcats]

I have no idea what your error is about.

Your code compiles and links with no errors or warnings using Visual Studio.NET 2005.