How to have common pointer for independent classes

Question

Hi

I have a class ( for eg. clsMain) which is responsible currently to call the methods of seperate class (For eg. clsA) . This class clsMain has pointer of the clsA class and it is working fine

Now scenario is that I need to work with clsB also and clsMain class based on input decides what to call for either clsA or clsB

I don't have control over clsA and clsB as it is owned by other group

How can I better use it in to clsMain ? I don't wana store pointer of both class but I don't find a way to store it in a single pointer due to the fact that they are independent classes

Any suggestions on this would be great.

Answer 1

Ketan Lalcheta it seems (at least to me) that this is a problem that can be solved using dynamic inheritance.
Have clsMain define an interface( a set of virtual functions ) and then let clsA and clsB define the implementation ( override the virtual functions ).

But since you've said that you don't have control over clsA and clsB, then the only solution is to define clsMain as having 2 pointers/objects of the 2 classes as member variables.

Answer 2

Anthony Maina Thanks.
this is something I will try....

But having said that, what's the difference if I access clsA method directly or access clsA object from clsMain

I still have to figure out which object or pointer of clsMain to use... Correct or I m missing something ?

Answer 3

Correct.
You still have to figure out which object to use, whether you are accessing their methods directly or through a clsMain object.

Answer 4

You may define your own type :
struct clsAB {
clsA a;
clsB b;
};
clsAB ab;
ab.a; //access clsA
ab.b; //access clsB

Answer 5

Yes that's correct ... But what benifit we will get by doing so ? Still I have to use condition to decide whether to write ab.a.function() or ab.b.function()

I need some mechanism which will work like ab.function which itself decided on a or b

Answer 6

A struct is like a class without methods, you know ? What's the condition to use one of these classes

Answer 7

That is user input... If input is 1 , then call a or else call b..

I will be calling this class a or class b method almost 100 times in entire code

So don't want to call each time using the if else condition

Answer 8

Does their methods have the same names ?

Answer 9

Yes it has... To be more specific, only one method is not to be called

Method1, method2 and method3 are called so many times

Answer 10

Is it what you want ? :
if(input) A ab();
else B ab();
ab.method1(); //this will work