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Re: [glas] introducing the storage concept, a first interface specification

From: Karl Meerbergen (Karl.Meerbergen_at_[hidden])
Date: 2005-01-25 09:12:56


Patrick Kowalzick wrote:

>
> When it is more efficient to swap yourself, you need IMO more
> information _about_ the storage you use to write a generic algorithm.
> This means you need information about the capacity and the speed
> (which may vary with the capacity). Otherwise you are not able to
> write the most effective algorithm.
>
> Even if you knew this, it is IMHO still a question of an orthogonal
> design to not use concepts of the container until it is necessary.
> E.g. I would prefer explicit usage of a container for temporaries
> (this is about what we are talking?) than using a concecpt:
>
> I would prefer
> disk_matrix<...> temporary = ....
> against
> matrix<....,disk_storage> temporary = ...
>
> Furthermore a concept does not describe the efficiency of the
> container implementation. Take a look at the different kinds of sparse
> matrix where the performance is dependant of the matrix structure.

I am not sure I understand all your points. The motivation for
discussing storage concepts are the following:

1) To allow algorithms to optimize for different ways of storage, so
algorithms are not orthogonal to storage
2) Container concepts and storage concepts are orthogonal to some extent

Karl