Re: [boost] Inheriting shared_ptr

From: Valentin Bonnard (Bonnard.V_at_[hidden])
Date: 2000-08-29 20:36:11

Greg Colvin wrote:
> 
> From: Valentin Bonnard <Bonnard.V_at_[hidden]>
> > Thomas Matelich wrote:
> >
> > > <whine> I wanna inherit shared_ptr </whine>
> > >
> > > Anyway, here's my situation, I'm writing a library for a simple plugin
> > > architecture.  Objects can be created from classes in dynamic libraries
> > > dynamically.  I want those objects to be shared_ptrs and be able to
> > > construct themselves.
> >
> > I don't understand.
> >
> > > I think this qualifies as an isa relationship.
> > > In general, their only purpose is to be used like a shared_ptr.
> > >
> > > So, is shared_ptr always going to use private for share and have no
> > > virtual destructor,
> >
> > Please explain why you think it should expose its implementation
> > details and why it should have a virtual destructor.
> >
> > > or is this matter up for discussion?
> >
> > We can discuss it, but I think I know the outcome.
> 
> I wouldn't be so sure.
> 
> We've been considering an improvement to shared_ptr to
> add template constructors parameterized on a function
> or functor that does the deletion. 

I have proposed some generalisations on std::auto_ptr 
and boost::*_ptr, and the answer has always been: keep 
it simple.

> We can arrange it
> so that type of shared_ptr(T*) is the same as the type
> of shared_ptr(T*,deleter), 

Defaulted template parameter class Desallocator=boost::Delete ?

Inherit shared_ptr<T*> from generalised_shared_ptr<T*, Delete> ?

> which might provide for the sort of polymorphism Thomas wants.  

I still don't understand.

-- 
Valentin Bonnard