Re: [boost] [ptr_container] new_clone overload

Subject: Re: [boost] [ptr_container] new_clone overload
From: Frank Mori Hess (frank.hess_at_[hidden])
Date: 2009-08-20 10:36:43

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On Thursday 20 August 2009, Thorsten Ottosen wrote:
> Frank Mori Hess skrev:
> > I've noticed that ptr_container/clone_allocator.hpp contains an
> > undocumented overload of new_clone that accepts a pointer-to-const:
> >
> > template< class T >
> > inline T* new_clone( const T* r );
> >
> > It is annoying because it doesn't support a pointer-to-non-const
> > argument, resulting in a compile error if you try.  Any chance one of the
> > following could be done?
>
> Yes, which do you prefer?

1,2, or 4 are all equally fine to me.  Actually, I'm currently in the process 
of moving away from new_clone to a "placement" version of it for 
generic_ptr::cloning (a cloning smart pointer class).  That will let me avoid 
having to do two allocations for every copy of generic_ptr::cloning, by using 
a boost::aligned_storage inside the clone allocator.  Also, my versions of 
new_clone and CloneAllocator will have to be generalized slightly to support 
generic pointer-like objects in addition to plain old pointers.

> > 1) remove it
> >
> > 2) add a pointer-to-non-const overload
> >
> > 3) change it to
> > template< class T >
> > T* new_clone( T* r );
> >
> > 4) or if you care about always returning a pointer-to-non-const change it
> > to template< class T >
> > typename remove_const<T>::type * new_clone( T* r );
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