🚀 go-pugleaf

Karl Heinz Buchegger wrote:

> 
> 
> Christopher Deli wrote:
> 
>> The thing is that the assignment I am working with demands that I have a
>> base class A with two subclasses (B and C) and I need to make ONE list 
>> with
>> both B and C objects. A should be an abstract class. So I need to 
>> create an
>> A pointer which sometimes points on B objects and sometimes on C objects.
>> And on top of that I need an operator which can add two B objects. If 
>> I only
>> put the operator in class B it wont work if the pointers I try to add 
>> have
>> static type A and dynamic type B.
>>
> 
> 
> First of all: please don't top post.
> Scroll to the section you want to reply to, and insert
> your comments there.
> 
> As you have seen, there is a technical problem with having
> an operator: the return type.
> Are you sure you *must* implement an operator or will an
> ordinary member function be sufficient?
> If your assignment explicitely states an operator, then I
> would suggest to ask your teacher, how he thinks this should
> work (Hint: it is impossible, since operator+ has to return
> an object, but for polymorphism you would need a pointer or
> a reference).
> 

I should have said: It is impossible without giving the operator+
a very unusual semantics. Something you definitly want to avoid.


-- 
Karl Heinz Buchegger
kbuchegg@gascad.at