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unboxing options
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Date: 2005-05-11 (18:50)
From: Christophe Raffalli <christophe.raffalli@u...>
Subject: Re: [Caml-list] unboxing options
Mike Hamburg wrote:
> Why should we need an "unboxed" keyword?  Is there any reason why the
> user should want things to be boxed?

Yes many reason:

- Unboxing of data structure prevent sharing of data structure and
   1 it may increase the memory usage
   2 it changes the semantics in presence of mutable data or ==
   3 it cost time to get the data out of the structure (needs copying)

So in fact, you only want unboxing for small object that have little
chance to be shared.

You could correct 2 and 3 if you allow pointer in the middle of the data
structure, but this is a nightmare for GC and runtime ...

Christophe Raffalli
Université de Savoie
Batiment Le Chablais, bureau 21
73376 Le Bourget-du-Lac Cedex

tél: (33) 4 79 75 81 03
fax: (33) 4 79 75 87 42
mail: Christophe.Raffalli@univ-savoie.fr
www: http://www.lama.univ-savoie.fr/~RAFFALLI
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