Boost logo

Boost :

From: Joaquín M LópezMuñoz (joaquin_at_[hidden])
Date: 2008-02-04 15:44:57

Michael Fawcett <michael.fawcett <at>> writes:

> On Feb 4, 2008 12:16 PM, Joaquín Mª López Muñoz <joaquin <at>> wrote:
> >
> > Good to know there's a potential for the keyed variant. Would you support
> > then the provision of regular flyweight and also keyed_flyweight as exposed
> > in my prior post?
> I support the notion of being able to lookup existing instances by
> key. However you implement it, I hope it will have an elegant syntax,
> and an extremely efficient implementation. Remember that this pattern
> is used often in games and 3D graphics, where extra copies are not an
> option, regardless of how pretty it makes the code look.

Besides regular flyweight and keyed_flyweight, there's a third
potential variant, namely tha in which the flyweight is
keyed but the key is not stored separately and can be obtained
from T. I'd like to ask you: in your particular use cases, do
your mesh classes store (apart from their data) the name of
the file the data was brought from, i.e. can you obtain
K from T? I wonder whether this third variant is worth implementing
after all, given ther difficulties STL containers have at
comparing elements with external keys.

> I intended on doing a review but regrettably don't have time to review
> this library. Good luck! Your libraries are high quality and I enjoy
> using them, so I hope Flyweight gets accepted.

Thanks for your compliments. The review has brought forward a
good number of issues. Regardless of what the review outcome is,
I'll have to rethink much of what I've written.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Boost list run by bdawes at, gregod at, cpdaniel at, john at