Re: [c-prog] Calling a virtual function from another virtual function in a derived class

[wang jun]

On Sat, 2007-11-24 at 13:25 +0000, sowmya wrote:
> Hello,
> I wanted to know if calling a virtual function from another 
> virtual function is valid or not.
Yes, you can. 
> I was working on an assignmnet where 
> the functions are pure in the base class and have definitions in the 
> derived class.
> I used g++ to compile the code and I was getting a runtime error 
> saying "pure virtual function called. aborted".
> The program executes fine when the declaration is removed in the 
> base class.Can anyone please tell me the reason? 
> 
> I have included the brief structure of the code
> class base
> {
> public:
> virtual void abc() ;
pure virtual: virtual void abc() = 0;
> virtual void efg();
> };
> 
> class derived: public base
> {
> public:
> virtual void abc(){ }
> virtual void efg(){ ...
> abc();
> ...
> }
> };
> 
> Regards,
> Sowmya
> 
I don't see there is a problem here. I have wrote a test 
program to verify it:

#include <iostream>

using namespace std;

class Base
{
    public:
        virtual void procedure() = 0;
        virtual void signature() = 0;
};

class Derived : public Base
{
    public:
        virtual void procedure()
        {
            cout << "procedure called" << endl;
        }

        virtual void signature()
        {
            this->procedure();
            cout << "signature called" << endl;
        }
};

int main()
{
    Derived subclass;
    subclass.signature();

    return 0;
}

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