A non abstract child class must implement all pure virtual function of parent abstract class in c++

Question

Hi,
In Indesign SDK there is a class  IActionComponent having two pure virtual functions:
virtual void
UpdateActionStates(IActiveContext* ac, IActionStateList *listToUpdateGSysPoint mousePoint = kInvalidMousePoint, IPMUnknown* widget = nil) = 0;
virtual void
DoAction(IActiveContext* ac, ActionID actionID, GSysPoint mousePoint = kInvalidMousePoint, IPMUnknown* widget = nil)= 0;
But, the child class
class WIDGET_DECL CActionComponent : public IActionComponent
implements only UpdateActionStates function and not DoAction function.
There is no compilation error and the code is running fine..HOW
Can some one please explain me?

Answer 1

Oops!!! there is a small correction in my C++ program. The JunkMethod is being called from the constructor...like the following code.
#include <iostream.h>
#include <stdlib.h>
class Base
    public:
        Base()
            cout<<"In Base Class constructor..."<<endl;
            JunkMethod();
        void JunkMethod()
            TestAbsFunc();
        virtual void TestAbsFunc()= 0;
class TestAbstract:public Base
    public:
        TestAbstract()
            cout<<"In Extend Class constructor..."<<endl;
        void TestAbsFunc()
            cout<<"In TestAbsFunc...."<<endl;
int main()
      TestAbstract test;
      return 0;
}You can see the change in the constructor of the Base class. JunkMethod is being called, just to bluff the compiler to call the virtual method (so that it won't crib saying that abstract method cannot be called from the constructor). When Java is supporting this functionality without giving any errors, C++ gives errors when you call an abstract method from the constructor or fails to execute when I do some work around like this. Isn't it a drawback of abstract funcationality supported by C++ (I'm not sure if it's a drawback or not)
Regards,
Kalyan.