rust-index: find_gca_candidates bit sets genericization
This allows to use arbitratry size of inputs in `find_gca_candidates()`.
We're genericizing so that the common case of up to 63 inputs can be
treated with the efficient implementation backed by `u64`.
Some complications with the borrow checker came, because arbitrary sized
bit sets will not be `Copy`, hence mutating them keeps a mut ref on the `seen`
vector. This is solved by some cloning, most of which can be avoided,
preferably in a follow-up after proof that this works (hence after exposition
to Python layer).
As far as performance is concerned, calling `clone()` on a `Copy` object
(good case when number of revs is less than 64) should end up just doing a
copy, according to this excerpt of the `Clone` trait documentation:
Types that are Copy should have a trivial implementation of Clone.
More formally: if T: Copy, x: T, and y: &T, then let x = y.clone();
is equivalent to let x = *y;.
Manual implementations should be careful to uphold this invariant;
however, unsafe code must not rely on it to ensure memory safety.
We kept the general structure, hence why there are some double negations.
This also could be made nicer in a follow-up.
The `NonStaticPoisonableBitSet` is included to ensure that the
`PoisonableBitSet` trait is general enough (had to correct `vec_of_empty()` for
instance). Moving the genericization one level to encompass the `seen`
vector and not its elements would be better for performance, if worth it.
[This file is here for historical purposes, all recent contributors
should appear in the changelog directly]
Andrea Arcangeli <andrea at suse.de>
Thomas Arendsen Hein <thomas at intevation.de>
Goffredo Baroncelli <kreijack at libero.it>
Muli Ben-Yehuda <mulix at mulix.org>
Mikael Berthe <mikael at lilotux.net>
Benoit Boissinot <bboissin at gmail.com>
Brendan Cully <brendan at kublai.com>
Vincent Danjean <vdanjean.ml at free.fr>
Jake Edge <jake at edge2.net>
Michael Fetterman <michael.fetterman at intel.com>
Edouard Gomez <ed.gomez at free.fr>
Eric Hopper <hopper at omnifarious.org>
Alecs King <alecsk at gmail.com>
Volker Kleinfeld <Volker.Kleinfeld at gmx.de>
Vadim Lebedev <vadim at mbdsys.com>
Christopher Li <hg at chrisli.org>
Chris Mason <mason at suse.com>
Colin McMillen <mcmillen at cs.cmu.edu>
Wojciech Milkowski <wmilkowski at interia.pl>
Chad Netzer <chad.netzer at gmail.com>
Bryan O'Sullivan <bos at serpentine.com>
Vicent Seguí Pascual <vseguip at gmail.com>
Sean Perry <shaleh at speakeasy.net>
Nguyen Anh Quynh <aquynh at gmail.com>
Ollivier Robert <roberto at keltia.freenix.fr>
Alexander Schremmer <alex at alexanderweb.de>
Arun Sharma <arun at sharma-home.net>
Josef "Jeff" Sipek <jeffpc at optonline.net>
Kevin Smith <yarcs at qualitycode.com>
TK Soh <teekaysoh at yahoo.com>
Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl>
Samuel Tardieu <sam at rfc1149.net>
K Thananchayan <thananck at yahoo.com>
Andrew Thompson <andrewkt at aktzero.com>
Michael S. Tsirkin <mst at mellanox.co.il>
Rafael Villar Burke <pachi at mmn-arquitectos.com>
Tristan Wibberley <tristan at wibberley.org>
Mark Williamson <mark.williamson at cl.cam.ac.uk>