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Glas :Re: [glas] unallocated fill |
From: Neal Becker (ndbecker2_at_[hidden])
Date: 2005-10-03 07:25:29
On Monday 03 October 2005 7:56 am, Karl Meerbergen wrote:
> Neal Becker wrote:
> >On Monday 03 October 2005 3:19 am, Karl Meerbergen wrote:
> >>On Friday 30 September 2005 20:22, Neal Becker wrote:
> >>>Suggest adding to dense_vector.hpp:
> >>> dense_vector(size_type size, value_type const& init)
> >>>
> >>> : size_( size )
> >>>
> >>> {
> >>> begin_ = alloc_.allocate( size ) ;
> >>> std::uninitialized_fill (begin(), end(), init);
> >>>
> >>> }
> >>>_______________________________________________
> >>>glas mailing list
> >>>glas_at_[hidden]
> >>>http://lists.boost.org/mailman/listinfo.cgi/glas
> >>
> >>Hi Neal,
> >>
> >>Personally, I prefer a free function fill( v, init ) ;
> >>Similarly, clear_values() and clear() also are free functions.
> >>rather than a member function. I agree that some form of initialization
> >> is quite useful.
> >
> >It is important to separate allocation and initialization for HPC. Here
> > is what I believe. The default construction should not perform
> > initialization. It looks to me that glas already follows this. If you
> > want initialization, use the alternative constructor as I show above.
>
> I agree about the point on separation of initialization and allocation.
> This is indeed how GLAS now works.
>
> The only difference with your suggestion is not to provide an
> initializing constructor, but use a free function. I prefer not to
> overload the collections with constructors, if it is not really needed.
> Is there a reason why you would prefer a constructor?
>
Thanks. The free function is fine. I suggested this because it is consistent
with STL, so maybe more familiar.