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[library submission] smoothsort
by Edouard A. 16 Dec '08

16 Dec '08

Hello, I just finished a C++ implementation of the smoothsort algorithm (a derivative of the heapsort algorithm by Dijkstra that, in his words, "is of order N log N in the worst case, but of order N in the best case, with a smooth transition between the two"). When sorting nearly sorted containers smoothsort achieves excellent performances. If you keep sorting the same container, smoothsort may be the right algorithm for you. This implementation works on all sortable containers, with best performances on containers supporting random access iterators (in other words, smoothsorting a std::list is quite slow). It only requires the "<" operator between two elements and the user can supply the function with a binary predicate. To my knowledge, there is no equivalent public C++ implementation. I was wondering if this was interesting enough to be included in the boost library. Kind regards. -- Edouard Alligand

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[result_of] Ticket #1535 ("remove unneeded headers")
by Richard Webb 16 Dec '08

16 Dec '08

I see that Ticket #1535 (https://svn.boost.org/trac/boost/ticket/1535) was fixed on Trunk a year ago, but doesn't seem to have made it to the release branch. Can the change be merged across for 1.38? Thanks, Richard Webb -- View this message in context: http://www.nabble.com/-result_of--Ticket--1535-%28%22remove-unneeded-header… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Is there any interest in a vector-like container for small integers class?
by Václav Haisman 16 Dec '08

16 Dec '08

Hi, is there any interest in a vector-like container for small integers class? The idea is to bit pack small integers into (size_t) units of underlying type. -- VH

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tweaking the review process (was: signals2 review results)
by Stjepan Rajko 16 Dec '08

16 Dec '08

Hi Paul, On Fri, Nov 21, 2008 at 1:00 AM, Paul Baxter <pauljbaxter(a)hotmail.com> wrote: > On Thu, Nov 20, 2008 at 11:40 PM, vicente.botet <vicente.botet(a)wanadoo.fr> wrote: >> I would like to make some suggestion to improve the review management: > > <valid points snipped> > > Whilst I understand your points, unlike our day job, people do have other > more pressing commitments and, for many, the extensive effort given to > reviewing boost libraries is time given in an ad-hoc manner. > > Whilst it is good to have the timetable and a specific method for submitting > reviews, I don't think we need to go further and be more regimented. The > existing flexibility is a positive part of the process, IMHO. I also tend to prefer flexibility when people are volunteering their time. > > [ I do have problems with some libraries actually getting to the point of > review before interest, maturity of interface or implementation are right, > but that doesn't apply here and has been covered in previous discussions.] > I think I was guilty of this / have been bit by this myself. Anyway, there are two things that I think can help here: * requiring a certain number of committed reviewers before scheduling a review * the review manager being more active in examining the library before the actual review About the latter - in both reviews I managed, there was a number of issues (e.g., documentation shortfalls) that came up during the review that I, as review manager, could have discussed privately with the author beforehand had I done a more thorough review of the library. These issues could have been fixed before a review was scheduled, and the reviews could have been more focused on other issues. The review process page states: "The Review Manager... Checks the submission to make sure it really is complete enough to warrant formal review. See the Boost Library Requirements and Guidelines. If necessary, work with the submitter to verify the code compiles and runs correctly on several compilers and platforms." Well, in both cases I had examined the library, tried it on several compilers, read the docs, glanced at the implementation, etc. But it wasn't a thorough review. I think, had I actually gone through the reviewer's list of questions and wrote a full review, it would have given the authors some idea of possible areas that can be improved before the review (being careful not to react prematurely in possibly contentious areas where the opinion of just one person is not enough). Doing something like this would require additional effort from the review manager, but I think it would result in a much better review (and one where it is possibly easier to make a decision because there are fewer remaining problems). Best, Stjepan

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config macro for presence of unordered containers?
by David Abrahams 15 Dec '08

15 Dec '08

Hi John, I'd like to suppress GCC's backward-compatibility warnings by using <unordered_set> instead of <backward/hash_set> or whatever it is, but I can't find a config macro that tells me <unordered_set> is available. Can we set one up, or something else I can use for that purpose? Thanks, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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[release][flyweight] permission for merging to release
by JOAQUIN M. LOPEZ MUÑOZ 15 Dec '08

15 Dec '08

Hello, I hereby request permission to merge Boost.Flyweight into the release branch in time for Boost 1.38: Docs: http://tinyurl.com/6jvfss Trunk test results: http://tinyurl.com/6ogxkt Trunk test results are satisfactory to me (many yellow cells are actually due to environmental problems with the regression testers, or else correspond to plain broken testers). I don't foresee any complication in the merging process. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Fw: Making a new contribution - weak_hash_map
by Yoni Lavi 15 Dec '08

15 Dec '08

Anyone? am I sending this to the right mailing list? It doesn't seem like I've gotten any reply to this. If there is some general principle precluding this contribution from being considered, please let me know. ----- Forwarded Message ---- From: Yoni Lavi <l_yoni(a)yahoo.com> To: boost(a)lists.boost.org Sent: Friday, November 28, 2008 3:09:33 AM Subject: Making a new contribution - weak_hash_map I'd like to contribute a C++ class template that implements something similar to java.util.WeakHashMap; it uses boost::intrusive::iunordered_set and boost::pool::fast_pool_allocator internally. This is the first time I'm looking to get into boost development in general. I'm not aware of any trivial way to implement this using existing components of the boost library, but I could have easily overlooked something so let me know if I am mistaken. I'd also like to know if there's any interest in such a contribution at all - anyone else thinks this class could be useful? Briefly, given a key space and value space, the class provides a way to lookup (and optionally create) values by a unique key, in a thread safe manner. A smart pointer to the entry (<key, value> pair) is returned from the lookup/create function. The tricky part is to make such entries automatically destroy themselves when no longer in use. The set itself cannot store a shared_ptr or the use count would never reach zero; it has to rely on weak_ptr and try to lock() it. There is also a race condition that needs to be taken care of (lock() may fail if refcount just dropped to zero in another thread). Lastly, it also has to handle the case where the weak_hash_map is destroyed but its entries persist, and again this needs to be properly synchronized. The implementation makes use of insert_check and insert_commit to implement a "create-or-get" function as well. I have also written an intrusive smart pointer type and that made it possible to use raw pointers instead of the weak_ptr's in the implementation. It's not that this stuff is rocket science as much as it involves lots of boilerplate code (e.g. making an entry hasher out of a key hasher, key/entry and entry/entry equality from key/key equality, resizing the hash table automatically, synchronization, allocation... the class I've written takes care of a lot of the ugly details. If anyone's interested, please fill me in on the process of making such a contribution? Thanks.

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<build>no in common properties
by K. Noel Belcourt 15 Dec '08

15 Dec '08

Hi, The Sandia-darwin-intel-11.0 results are failing because essentially every Boost product is not being built (actually being skipped). This message is present for almost every Boost library. Skipping build of: ../libs/date_time/test/date_time_serialization <build>no in common properties Skipping build of: ../libs/disjoint_sets/disjoint_sets <build>no in common properties Skipping build of: ../libs/dynamic_bitset/dynamic_bitset <build>no in common properties Skipping build of: ../libs/exception/test/is_output_streamable_test <build>no in common properties Any idea what's up with this? The Sandia-leopard-x86 results didn't seem to suffer from this problem last night. Thanks. -- Noel

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Measuring compile time performance
by dan marsden 15 Dec '08

15 Dec '08

Hi We're looking at optimizing some of the compile time performance in Boost.Fusion. I'm looking for any experience in Boost of measuring build times / compile time cost, how to structure tests that cover it etc. Does Boost.Build provide any support for measuring compile time for example? I'm aware there's a Perl script by Steven Watanabe that measures template instantiations if I understand correctly. Are there any other techniques that are being used that I should be aware of? Cheers Dan Send instant messages to your online friends http://uk.messenger.yahoo.com

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Re: [boost] [Boost-users] BoostCon 2009: Call for Participation
by Raindog 15 Dec '08

15 Dec '08

Hartmut Kaiser wrote: > Hi all, > > before we all relax into the holidays I wanted to remind you all about next > year's Boost Conference in Aspen, CO, USA, May 3-9. Even if all important > dates are listed in the attached Call for Participation, I'll list them here > once again: > > Proposals for submissions due: January 10th 2009. > Proposals acceptances sent (tentative program available): February 10th, > 2009 > Fully scheduled program available: March 1st, 2009 > Session materials due: April 1st 2009. > > IOW, you might want to use some of your free time during the next weeks to > think about a possible contribution. It really doesn't take much time to > come up with a short abstract! > > Let's make sure BoostCon 2009 will be a major C++ event! > > Happy holidays! > Regards Hartmut > > Program Committee Chair > BoostCon 2009 > Any idea when the boostcon website will be updated with 2009 info?

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