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[svn] log message change request
by JOAQUIN M. LOPEZ MUÑOZ 16 Dec '08

16 Dec '08

I know this is nitpicking, but I've just commited the change 50300 to the repository: https://svn.boost.org/trac/boost/changeset/50300/ and I'd like the associated log message to be changed from up to rev. 49674 from trunk to merged up to rev. 49674 from trunk Apparently, I cannot change this myself due to the current repository configuration and I can't make myself content about leaving the wrong message there :-/ Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Re: [boost] [library submission] smoothsort
by dpxguard-boost＠yahoo.gr 16 Dec '08

16 Dec '08

> >David Abrahams wrote: > >>on Sun Dec 14 2008, Christopher Jefferson wrote: > >>>I have often been surprised at the lack of an algorithms library > >>>in boost. There has > >>>often been times I've wished for a guarded or unguarded insertion > >>>sort, or riffle > >>>shuffle. Is his lack just down to no-one stepping forward to help > >>>write and maintain > >>>such a library of algorithms? > >> > >>Seems like it > > > >I seem to recall that at BoostCon this year, there was a push to > >extend the algorithm support in Boost as part of the Library in a > >Week program. Did anything significant come of that? > > There's some stuff in the sandbox (some of which I wrote), but as far > as I know, none has come up for review. I'm hoping to get off my duff > and write some docs and get some of it reviewed before this year's > BoostCon. In case you are interesting in advanced search-algorithms as well, there is also a generic sequence searching template function in the vault. (Algorithms/single_pass_search) This algorithm is more generic than std::search (works with input-iterators) and has better worst case complexity at the same time. (See also http://www.codeproject.com/KB/stl/single_pass_search.aspx) Best Regards, Jim Xochellis ___________________________________________________________ Χρησιμοποιείτε Yahoo!; Βαρεθήκατε τα ενοχλητικά μηνύματα (spam); Το Yahoo! Mail διαθέτει την καλύτερη δυνατή προστασία κατά των ενοχλητικών μηνυμάτων http://login.yahoo.com/config/mail?.intl=gr

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[graph] boost::plugin and boost::id_tag ?
by remi.chateauneu＠gmx.de 16 Dec '08

16 Dec '08

Hi, I try to run an example here: http://www.boost.org/doc/libs/1_37_0/libs/property_map/iterator_property_ma… typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, boost::no_plugin, boost::plugin<boost::id_tag, std::size_t> > Graph; I cannot find boost::plugin and boost::id_tag. Any idea, please ? Thanks

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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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[serialization] Does this have any effect?
by David Abrahams 14 Dec '08

14 Dec '08

Hi All/Robert, I've been using the enclosed "untracked" wrapper around some things that I've been serializing... but I think I may have been barking up the wrong tree. Does it have any effect? In other words, I suspect that ar << untracked(anyexpression) is equivalent to ar << anyexpression Is that the case? Thanks in advance, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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[proto][design]why unary_expr,binary_expr; but no nullary_expr?
by Larry Evans 14 Dec '08

14 Dec '08

Although there's unary_expr<Tag,*>, binary_expr<tag.*,*> in traits.hpp there's no nullary_expr<Tag>. I realize this would be a replacement to the current terminal template but with a user specified tag. After all, if a user specified tag for n-ary (where n>0) expressions *is* desirable, why is a user specified tag for 0-ary expressions *not* desirable? On case where this would be useful is for algebraic morphisms where n-ary ops in a source algebra are mapped to n-ary ops in a target algebra. This *includes* 0-ary ops. An op would be the equivalent to proto tags. I think this could be done by another transform similar to the pass_through transform but allowing transformation of the tag. Currently pass_through just uses the source tag in the target expression. It seems like it should be pretty easy to allow transformation on the tag also.

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BoostCon 2009: Call for Participation
by Hartmut Kaiser 13 Dec '08

13 Dec '08

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

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[thread] reset a thread_specific_ptr by this pointer
by Pengcheng Song 12 Dec '08

12 Dec '08

Hi All, I was experimenting with the boost.threads library and especially boost::thread_specific_ptr. However, I ran into problems trying to reset the thread_specific_ptr by the this pointer (see the code below). // ========= beginning of code ============= #include <iostream> #include <boost/thread/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/thread/tss.hpp> boost::mutex mutex_; class A { private: double x_; static boost::thread_specific_ptr ptr_; public: A(double x=0) : x_(x) {} void operator()() { if (0==ptr_.get()) { ptr_.reset(this); } boost::mutex::scoped_lock lock(mutex_); std::cout << "x_=" << x_ << std::endl; } }; boost::thread_specific_ptr A::ptr_; int main() { boost::thread thrd1( A(1) ); boost::thread thrd2( A(2) ); thrd1.join(); thrd2.join(); return 0; } // ======= end of code ========= This compiled fine with boost_1_36 (binary from boostPro) under VC9 with multithreaded debug DLL code generation. But when I ran it under the debug mode, I got the following error message: Debug Assertion Failed. Expression: _BLOCK_TYPE_IS_VALID(pHead->nBlockUse) I searched the web and this seemed to be a memory problem. And I noticed that it failed to call the destructor of thread_specific_ptr. Is my code legal? Or one is not supposed to reset a thread_specific_ptr to this pointer? Your feedback would be greatly appreciated. Pengcheng Song -- View this message in context: http://www.nabble.com/-thread--reset-a-thread_specific_ptr-by-this-pointer-… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[iterators] how about an identity_iterator or generate_iterator?
by Dean Michael Berris 12 Dec '08

12 Dec '08

Hi, Has anybody found a need for an "identity_iterator"? Something that you can initialize to a value and returns that value every time it's referenced? It could model a random access iterator, and a default constructed version will mark an "end" of the identity_iterator. Something to the effect of: template <class Type> struct identity_iterator { identity_iterator(size_t count = 0) : v_(), count_(count) {} identity_iterator(const identity_iterator & o) : v_(o.v_), count_(o.count_) {} Type operator*() { return v_; } identity_iterator & operator++() { ++count_; *this; } identity_iterator & operator++(int) { ++count_; *this; } bool operator==(identity_iterator const & rhs) { return (this->count_ == rhs.count_); } bool operator<(identity_iterator const & rhs) { return (this->count_ < rhs.count_); } // ... and other required iterator nested types private: Type v_; size_t count_; }; Or even a "generate_iterator" which takes a nullary function object of signature "tuple<bool, T>()" where bool indicates whether it's at the end? It can be modeled as an input iterator. Something like: template <class T> struct generate_iterator { generate_iterator() : f_(), at_end(true) { } generate_iterator(function<tuple<bool, T>() > f) : f_(f), at_end(false) { } // copy constructor, swap, assignment, etc. T operator* () { T return_; tie(at_end, return_) = f_(); return return_; } // other required nested types private: function<tuple<bool, T>()> f_; bool at_end; }; Or is there already something out there which allows these iterator semantics? -- Dean Michael C. Berris Software Engineer, Friendster, Inc.

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Re: [boost] [review][constrained_value] Review of Constrained Value Library begins today
by Kim Barrett 12 Dec '08

12 Dec '08

At 2:23 PM +0100 12/6/08, Robert Kawulak wrote: >... maybe the problem >could be somehow solved if we have a function float exact(float) that, given a >floating point value (that may have greater precision because of caching in a >register), returns a value that is truncated (has exactly the precision of >float, not greater). I think that something along the lines of the following will likely work: inline double exact(double x) { struct { volatile double x; } xx = { x }; return xx.x; } The idea is to force the value to make a round trip through a memory location of the "correct" size. The use of volatile should prevent the compiler from optimizing away the trip through memory. If worried about whether a compiler will really do what's needed here, then I think the only other option is inline assembler to produce the equivalent behavior. Looking through the x86 instruction set, I don't see any other way to cause the desired rounding.

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[Graph] random_access_iterator_property_map
by remi.chateauneu＠gmx.de 11 Dec '08

11 Dec '08

Hi, I try to use random_access_iterator_property_map following the example here: http://www.boost.org/doc/libs/1_37_0/libs/graph/doc/using_property_maps.html I have exactly the same problem mentioned here, on 2003-01-04 : http://www.mail-archive.com/boost@lists.boost.org/msg02627.html The interesting thing is that the documentation is still not updated, and there are still occurences of this class: /usr/include/boost/graph/detail/self_avoiding_walk.hpp: SAW_visitor< random_access_iterator_property_map<Tri*,Tri,Tri&>, /usr/include/boost/graph/detail/self_avoiding_walk.hpp: HList, random_access_iterator_property_map<Iter*,Iter,Iter&> > /usr/include/boost/graph/detail/self_avoiding_walk.hpp: typedef random_access_iterator_property_map<Tri*,Tri,Tri&> TriD; /usr/include/boost/graph/detail/self_avoiding_walk.hpp: typedef random_access_iterator_property_map<Iter*,Iter,Iter&> IterD; Is it a mistake from me, or ? Thanks

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[ref] provide unref( T& )?
by Thorsten Ottosen 11 Dec '08

11 Dec '08

Hi, To be able to call a function object wrapped in boost::reference_wrapper<T>, we need something like the following: template< class T > inline typename boost::unwrap_reference<T>::type& unref( T& value ) { return static_cast<typename boost::unwrap_reference<Fun>::type&>(value); } which can then be used like template< class Fun > int algorithm( Fun fun ) { return unref(fun)(42); } any objections to adding this to ref.hpp? -Thorsten

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[variant]compile-time-checked boost::get<T>?
by Arno Schödl 11 Dec '08

11 Dec '08

Hello, I just replaced our own union implementation by boost::variant and was surprised that boost::get<T> does not compile-time check T. IMHO, boost::get<T> should only compile if T is a possible member of the variant. We implemented this with an enable_if without much difficulty. As a further extension, boost::get<S> where S is a base class of a T contained in the variant, should also work. I believe this would also be implementable with enable_if/disable_if, but we have not done it, so no guarantee. Arno -- Dr. Arno Schoedl · aschoedl(a)think-cell.com Technical Director think-cell Software GmbH · Invalidenstr. 34 · 10115 Berlin, Germany http://www.think-cell.com · phone +49-30-666473-10 · toll-free (US) +1-800-891-8091 Directors: Dr. Markus Hannebauer, Dr. Arno Schoedl · Amtsgericht Charlottenburg, HRB 85229

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[constrained_value] need help with runtime error
by Neal Becker 11 Dec '08

11 Dec '08

This code has an error: #include <boost/numeric/ublas/vector.hpp> #include <boost/constrained_value.hpp> namespace cv = boost::constrained_value; namespace ublas = boost::numeric::ublas; typedef cv::bounded<int>::type val_t; typedef cv::bounded<int>::type::constraint_type constraint_type; int main() { int min = -200; int max = 200; val_t init (10, constraint_type (min, max)); ublas::vector<val_t> v (10, init); ublas::vector<val_t> w = -v; } This code will throw an exception. The last line invokes: ublas/functional.hpp:70 (scalar_negate), which for some reason calls constrained.hpp:224, which is: constrained(const value_type & v) That is, initialize only the value, not the constraint! Any ideas?

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[review][constrained_value] Review of Constrained Value Library begins today
by Jeff Garland 11 Dec '08

11 Dec '08

Hi all, The review of the Robert Kawulak's Constrained Value library begins today December 1, 2008, and will end on December 10th -- I will be the review manager. Please post reviews to the developer list. Here's the library synopsis: The Boost Constrained Value library contains class templates useful for creating constrained objects. A simple example is an object representing an hour of a day, for which only integers from the range [0, 23] are valid values. bounded_int<int, 0, 23>::type hour; hour = 20; // OK hour = 26; // exception! Behavior in case of assignment of an invalid value can be customized. The library has a policy-based design to allow for flexibility in defining constraints and behavior in case of assignment of invalid values. Policies may be configured at compile-time for maximum efficiency or may be changeable at runtime if such dynamic functionality is needed. The library can be downloaded from the here: http://rk.go.pl/f/constrained_value.zip The documentation is also available online here: http://rk.go.pl/r/constrained_value --------------------------------------------------- Please state in your review, whether you think the library should be accepted as a Boost library. Additionally, please consider the following aspects in your review of the library: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Thanks, Jeff

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[review][constrained_value] Review of Constrained Value Library begins today
by Jeff Garland 11 Dec '08

11 Dec '08

Hi all, The review of the Robert Kawulak's Constrained Value library begins today December 1, 2008, and will end on December 10th -- I will be the review manager. Please post reviews to the developer list. Here's the library synopsis: The Boost Constrained Value library contains class templates useful for creating constrained objects. A simple example is an object representing an hour of a day, for which only integers from the range [0, 23] are valid values. bounded_int<int, 0, 23>::type hour; hour = 20; // OK hour = 26; // exception! Behavior in case of assignment of an invalid value can be customized. The library has a policy-based design to allow for flexibility in defining constraints and behavior in case of assignment of invalid values. Policies may be configured at compile-time for maximum efficiency or may be changeable at runtime if such dynamic functionality is needed. The library can be downloaded from the here: http://rk.go.pl/f/constrained_value.zip The documentation is also available online here: http://rk.go.pl/r/constrained_value --------------------------------------------------- Please state in your review, whether you think the library should be accepted as a Boost library. Additionally, please consider the following aspects in your review of the library: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Thanks, Jeff

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