Re: [Boost-users] shared_ptr invalid covariant return type

From: Andy Rushton (quergle-mingw_at_[hidden])
Date: 2008-07-05 12:06:51

No, as I read it, the original author was not interested in covariant 
return types, he was asking how to solve the problem of writing clone 
methods for polymorphic classes. The solution is to *not* use covariant 
return types. This avoids the problem where shared_ptr<A> is a 
completely different and non-castable type to shared_ptr<B> - but if you 
do it the non-covariant way you don't have this problem because all your 
clone functions return shared_ptr<A>. Problem solved.

You'll get further in life if you make positive contributions, rather 
than putting down other people's.

Rodolfo Lima wrote:
> 
> And apparently you've forgotten what covariant return types are :)
> 
> Regards,
> rod