Boost logo

Boost :

From: John Maddock (john_at_[hidden])
Date: 2005-02-05 05:54:52

> There are several Boost-related projects underway around the theme of
> unordered containers (in my case, I'm pretty much on the verge
> of releasing a preview of hashed indices for Boost.MultiIndex.)
> All these projects have the common need of a hash<> implementation
> being available, preferrably promoted to a public namespace rather
> than as an implementation detail.


> Although Boost.TR1's purpose is not to implement new features but
> rather wrap them to achieve std::tr1-compliance, I think it'd be very
> useful if some tr1-hash implementation could be added to Boost.
> For the record, I'm currently using Jeremy Maitin-Shepard and
> Daniel James' implementation in Sanbox files/unordered.tar.gz. I
> think it is a rather solid implementation, taking care of compilers
> witohut PTS such as MSVC++ 6.0/7.0.

Yes, I would also like to see that added - it really just needs some docs -
there's not that much to review given that the design is fixed by the TR.

> As for the location, my pereference would be boost/functional/hash.hpp.
> Boost.TR1 could embrace this later in boost/tr1/functional.hpp.
> Could this be done? Maybe as a separate activity from Boost.TR1?
> Am I entitled to do it myself as part of the upgrade of my library,
> even though this would be adding a new library in disguise? As it
> happens, I think I'll be able to release hashed indices in time for
> Boost 1.33, but this detail can be a showstopper :(

Personally if your just talking about adding boost::hash<> (and not all the
containers as well), then I would be inclined to suggest that you go ahead,
although it might be better to place it (temporarily) either in detail, or
under the pending sub-directories, since it hasn't been reviewed etc.
Otherwise we might end up with another aligned_storage style clash at some
point (although a TR-conforming version should always take preference).

Anyone else want to throw in their thoughts? What's the timescale on the
unordered container development, how much is there left to do?


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