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Is heterogeneous container of boost::shared_p tr possible?

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Hi, first post and here it goes...

This is the current code (working) that I have. It works but for large number of A & B objects, it's not the most efficient. It's also not really heterogenous either. It's really just a storage of the parent class objects.
Expand|Select|Wrap|Line Numbers
  1. class A
  2. { … }
  3. class B:public A
  4. { … }
  5.  
  6. vector<A*> combined;
  7. vector<A> list_A;
  8. vector<B> list_B;
  9. for(size_t i=0; i<list_A.size();i++)
  10. {
  11.    combined.push_back(new A(list_A[i]));
  12. }
  13. for(size_t i=0; i<list_B.size();i++)
  14. {
  15.    combined.push_back(new B(list_B[i]));
  16. }
  17.  
So instead, I changed to using boost shared pointers for list_A and list_B.
Now, I still need to combined those two different vectos into a single one.
Something like this:
Expand|Select|Wrap|Line Numbers
  1. vector< boost::shared_ptr<A> > list_A;
  2. vector< boost::shared_ptr<B> > list_B;
  3. for(size_t i=0; i<list_A.size();i++)
  4. {
  5.    combined.push_back(list_A[i]);
  6. }
  7. for(size_t i=0; i<list_B.size();i++)
  8. {
  9.    combined.push_back(list_B[i]);
  10. }
  11.  
I’d like to do something like the above but I’m not sure how to define my
vector< … > combined;

Following the original method, I thought about:

Expand|Select|Wrap|Line Numbers
  1. vector<  boost::shared_ptr<A>  > combined; 
  2.  
So how would I populate combined from list_B?
even though B inherits A, you can't just replace boost::shared_p tr<A> with boost::shared_p tr<B> directly right?
Oct 26 '07 #1
1 1981
weaknessforcats
9,208 Recognized Expert Moderator Expert
How does B inherit A ??

If there are no virtual functions in A, then you can have a vector<B>.
Otherwise you cannot since the virtual function in A indicates polymorphism and that indicates using base pointers or referecnes only.

Therefore, if A has a virtual function, then you can have a vector of shhared_ptr. Since all calls use the A interface there's nothing to combine. You put the B objects in the vector as shared_ptr<A>.
Oct 27 '07 #2

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