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Re: [glas] unallocated fill

From: Karl Meerbergen (Karl.Meerbergen_at_[hidden])
Date: 2005-10-03 06:56:09


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?

Cheers,

Karl