December 2011 - Boost - lists.preview.boost.org

Re: [boost] Proposal for a Differential Evolution C++ library
by Adrian Michel 26 Dec '11

26 Dec '11

Hi everybody, I released a new version of the DE library based on feedback I received on the initial release - see the doc at http://www.amichel.com/de/doc/html. First of all, I updated the documentation to describe in more detail what DE is, its use in one specific case, and links to descriptions of several other use cases - see the Overview page at the link above. I hope this will help make the case why a DE library would be worth being included in boost. BTW, there are already implementations in several languages and for several free or commercial products: Java, C, Matlab, Scilab, Fortran90, Python, Labview, Pascal, C#, etc. As far as the library itself, Thomas Heller noted that requiring the objective functions to be derived from the de::objective_function abstract class limited the user options by not allowing arbitrary unnamed or plain functions to be passed as objective functions. I followed his suggestion and reimplemented parts of the library as template classes, in particular the de::processor class. It is now possible to pass objective functions as: named functions, unnamed functions, functors (all with the right prototype) or objective function factories which create local copies of the objective function. All of these can be passed as either references, plain pointers or boost::shared_ptr. This change should make it easier to integrate the library within existing code. Your comments will be appreciated. Adrian

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[string_algo] New Maintainer
by Pavol Droba 26 Dec '11

26 Dec '11

Dear Boosters, After a careful consideration I finally realized that I can no long act as a maintainer for String Algorithms Library. I simply don't have the required time and I thinks that the library deserves at least development. Therefore I would like to call for a volunteer(s) who would like to take String Algorithm library further. I will still be available for consultations or any such assistance if required. Hopefully I will be also able to contribute a bit if my situation changes. Now, I don't really know if there is an official process for this kind of shift. I would be nice if potential volunteers would send a few words about the future direction they would take. A community can make a decision then. Best Regards, Pavol

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[config, c++11] emplace_back check?
by Tim Blechmann 26 Dec '11

26 Dec '11

hi all, i wonder, is there a way to determine, if std::vector provides emplace_back? this currently causes a compile failure for boost.heap on gcc-4.3 with c++0x enabled: it does not implement emplace_back, although it has rvalue references and variadic templates. thanks, tim

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boost releases on microblogs
by Pedro Larroy 25 Dec '11

25 Dec '11

Hi Wouldn't it be nice to have twitter and identi.ca anouncements of boost releases? Regards. Pedro.

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Re: [boost] FW: Proposal for a Differential Evolution C++ library
by Adrian Michel 24 Dec '11

24 Dec '11

Hi Philip, On 12/09/2011 4:35 PM, Philip Bennefall wrote: >> The full documentation is at http://www.amichel.com/de/doc/html but I'd >> suggest these pages for a first read >> http://www.amichel.com/de/doc/html/dd/d53/overview.html and >> http://www.amichel.com/de/doc/html/db/d4e/tutorial.html . >> >> The zip containing the DE C++ library and helper files is at >> http://www.amichel.com/de/de.zip. >> >> The DE main page is at http://www.icsi.berkeley.edu/~storn/code.html . > I took a peak at the overview and some of the other pages and from what I > can see initially, it looks like a very useful library for artificial > intelligence. I have very limited knowledge in the field but this is > something that grabs my interest, so if it's made public I'll definitely use > Thanks for your interest. DE and this library can be certainly used for AI, but many different problems in various areas can be optimized efficiently using DE (references to some of those can be found here: http://www.icsi.berkeley.edu/~storn/code.html) Best, Adrian

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[geometry] MSVC needs namespace even if it is hoisted
by Barend Gehrels 24 Dec '11

24 Dec '11

Hi, We got a strange MSVC compilation problem in a Unit Test for Boost.Geometry. Attached a miminal reproduction. The essention is that we have stated: using strategy::distance::services::returning_type; and somewhere after that: typedef typename returning_type<strategy_type>::type the_return_type; but this is not accepted, in this case, by MSVC. It is well accepted by gcc, clang and comeau. If the namespace is specified, it is accepted by MSVC. The error message is: reproduce_msvc_using_bug.cpp(257): error C2059: syntax error : '<' And that is the same message as if the returning_type would not be a template. If we state: std::cout << typeid(returning_type).name() << std::endl; It compiles in MSVC, but it should not compile, because it is a template. So somehow it picks up this "returning_type" as if it is not a template. But of course it is. I've tried another (much smaller) minimal reproduction to mimic this problem but that is compiled normally by MSVC. So attached this one with (reworked) pieces from Boost.Geometry and even Boost, but still all contained in one file. We've discussed this internally and the current thought is that it is a compiler problem. If so, is this issue known to anyone on this list, or Microsoft? Otherwise I will report it. If not so, what is the problem here? It is of course easy to work around: giving the full namespace is OK for any compiler. So this is more out of curiosity: what is wrong here? Regards, Barend

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TRAC hit hard last night
by Marshall Clow 23 Dec '11

23 Dec '11

We got a major infusion of garbage; strictly speaking, it doesn't appear to be spam, because it's not advertising anything, and the text doesn't contain any links. However, it doesn't have anything to do with boost. I've deleted about 40 tickets this morning. Any suggestions on how to prevent this in the future? -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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C++11 challenge: ASSERT_INVALID_EXPR
by Dave Abrahams 23 Dec '11

23 Dec '11

I don't know whether this is actually possible, but I was thinking today that there might be a way to use the new SFINAE to detect errors in a large class of invalid expressions without actually causing a hard error, and thereby build an assertion that fails compilation when passed a valid expression and passes for any invalid expression in the large class mentioned above. Any takers? -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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[concept_check] Some issues
by Robert Kawulak 23 Dec '11

23 Dec '11

Hi, I've spotted some problems when playing with BCCL: - The implementation of assignable_archetype defines private default and copy constructors, so for example assignable_archetype<copy_constructible_archetype<>> will not actually be copy constructible. The same for convertible_to_archetype and convertible_from_archetype, but additionally with copy assignment. Is this by purpose? - copy_constructible_archetype defines public default constructor - again, am I overlooking something or it should not be there? - Function and predicate archetypes also seem to provide too wide interface (they are copy constructible and assignable). Additionally, they don't allow for archetypes chaining since they lack the Base parameter (with the only exception of binary_predicate_archetype - why the inconsistency?) - Apart from the provided function object concepts and archetypes it seems it would be useful to have a general Callable concept and the corresponding callable_archetype, parameterised with the types of arguments and return value. Wouldn't it be valuable to add them? - There's boost/concept_check directory in the trunk - are the files in it actually used anywhere? I've found no reference to them in Boost headers, documentation doesn't mention them too. Best regards, Robert

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boost and google search
by Edward Rankin 23 Dec '11

23 Dec '11

Hi, I am sure it is pretty common for users of boost to use google to search for documentation/tutorials on their favorite library in boost. I have found that the top hits are typically not the latest documents. For example I just searched for boost,foreach and a documentation from 1.35 was the first hit. It would be great if there is a way to tell google to update their links to the latest version. Anyone knows whether this is possible, and how to make it happen? This problem probably applies to any search engine but I can only comment on google search. Thanks, Edward

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constness in barrier.hpp
by Gaetano Mendola 23 Dec '11

23 Dec '11

Hi all, simple patch to make const the private member m_threshold in class barrier Regards Gaetano --- barrier.hpp.original 2011-12-22 12:05:05.921720854 +0100 +++ barrier.hpp 2011-12-22 12:05:36.936205847 +0100 @@ -52,7 +52,7 @@ private: mutex m_mutex; condition_variable m_cond; - unsigned int m_threshold; + const unsigned int m_threshold; unsigned int m_count; unsigned int m_generation; };

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[config] ok to merge forceinline changeset to release?
by Eric Niebler 23 Dec '11

23 Dec '11

I got a little overzealous and merged to release some code that uses BOOST_FORCEINLINE, only to discover that that macro doesn't exist on the release branch yet. The right fix is probably to get config in sync between the two branches. OK to merge [74917] to release? -- Eric Niebler BoostPro Computing http://www.boostpro.com

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Re: [boost] RFC: Multiprecision arithmetic library
by John Maddock 22 Dec '11

22 Dec '11

>I really like the idea, and the API looks good. > > Have you considered an MPIR backend, in addition to GMP and others? Being > the > Windows port of GMP, the interfaces and usage are identical. Nod, the two are treated the same - in fact I use MPIR for testing under Visual Studio. John.

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it would be nice if people logged into trac before commenting on tickets.
by Marshall Clow 22 Dec '11

22 Dec '11

That way we don't get things like this: > Changes (by anonymous): > > * status: new => closed > * resolution: => invalid Thanks, everyone! -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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Re: [boost] ASIO Query
by Olaf van der Spek 21 Dec '11

21 Dec '11

On Wed, Dec 21, 2011 at 9:21 PM, james(a)jamesbb.co.uk <james(a)jamesbb.co.uk> wrote: > Blocking - I've thought about this, but the MySQL C/C++ libraries unfortunately > don't provide asynchronous queries. > > I'm thinking of moving database reads into a seperate thread(s). It would be > nice if I can integrate this with the io_service, but I'm unsure how to do so. > Is it possible to pass arbitrary work items to an io_service, in the same manner > as async_read/write? Does every request involve blocking calls? If so, I'd not go with a 'shared nothing' design. Olaf

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Re: [boost] ASIO Query
by james＠jamesbb.co.uk 21 Dec '11

21 Dec '11

After a little reading of the ASIO documentation, it looks like I should be able to run a seperate io_service on another thread, and post() database queries to it. If I bind a callback with the query, the results/error can be passed back to the initiator without too much trouble. Seems like boost is the answer to everything. Assuming I can keep the database queries asynchronous, would anyone recommend HTTP example 2 or 3? Appreciated, thanks again. On 21 December 2011 at 20:21 "james(a)jamesbb.co.uk" <james(a)jamesbb.co.uk> wrote: > Blocking - I've thought about this, but the MySQL C/C++ libraries > unfortunately > don't provide asynchronous queries. > > I'm thinking of moving database reads into a seperate thread(s). It would be > nice if I can integrate this with the io_service, but I'm unsure how to do so. > Is it possible to pass arbitrary work items to an io_service, in the same > manner > as async_read/write? > > Many thanks. > > > > > On 21 December 2011 at 16:07 Olaf van der Spek <ml(a)vdspek.org> wrote: > > > On Wed, Dec 21, 2011 at 3:27 PM, james(a)jamesbb.co.uk > > <james(a)jamesbb.co.uk> wrote: > > > I'm hoping for opinions on using an io_service per core against a single > > > io_service with multiple threads (similar to HTTP Server examples 2 & 3). > > > The > > > application is a TCP authentication / proxy server, intended to use all > > > available cores. > > > > > > - The TCP streams consist of small messages (usually a few hundred bytes) > > > which > > > can individually be processed quickly. > > > - Connections themselves are fairly long lasting - average around 4 hours, > > > although occasionally up to 10-12 hours. > > > > > > We're looking for a 'shared nothing' design between threads - database > > > queries > > > can be made per-thread (using TLS), for example. > > > > Are database queries blocking or non-blocking? If they're blocking, > > won't this also block other connections handled by the same thread? > > > > Olaf > > > > _______________________________________________ > > Unsubscribe & other changes: > > http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] ASIO Query
by Olaf van der Spek 21 Dec '11

21 Dec '11

On Wed, Dec 21, 2011 at 3:27 PM, james(a)jamesbb.co.uk <james(a)jamesbb.co.uk> wrote: > I'm hoping for opinions on using an io_service per core against a single > io_service with multiple threads (similar to HTTP Server examples 2 & 3). The > application is a TCP authentication / proxy server, intended to use all > available cores. > > - The TCP streams consist of small messages (usually a few hundred bytes) which > can individually be processed quickly. > - Connections themselves are fairly long lasting - average around 4 hours, > although occasionally up to 10-12 hours. > > We're looking for a 'shared nothing' design between threads - database queries > can be made per-thread (using TLS), for example. Are database queries blocking or non-blocking? If they're blocking, won't this also block other connections handled by the same thread? Olaf

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Contact to lists.boost.org owners
by Mateusz Łoskot 21 Dec '11

21 Dec '11

Hi, I have tried to get in touch with ML managers at boost-owner(a)lists.boost.org I haven't received any response for a few days. What is the current contact to request new ML on lists.boost.org server? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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ASIO Query
by james＠jamesbb.co.uk 21 Dec '11

21 Dec '11

Hiya, I'm hoping for opinions on using an io_service per core against a single io_service with multiple threads (similar to HTTP Server examples 2 & 3). The application is a TCP authentication / proxy server, intended to use all available cores. - The TCP streams consist of small messages (usually a few hundred bytes) which can individually be processed quickly. - Connections themselves are fairly long lasting - average around 4 hours, although occasionally up to 10-12 hours. We're looking for a 'shared nothing' design between threads - database queries can be made per-thread (using TLS), for example. The application is written for Redhat Linux - I'm unsure if it makes a difference. Any suggestions are much appreciated! Cheers Jim

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[fusion] patch for #5010
by Jürgen Hunold 21 Dec '11

21 Dec '11

Hi, tow weeks ago I have attached a patch to https://svn.boost.org/trac/boost/ticket/5010 changing fusion::nil to fusion::nil_ for better compatibility with Obective-C and my case an ancient version of LEDA. Patch attached for convenience. The questions is how to proceed? May I commit the patch? Any documentation to change? Hoping for feedback, Yours, Jürgen -- Dipl.-Math. Jürgen Hunold | IVE mbH Software-Entwickler | Lützerodestraße 10 Tel: +49 511 897668 33 | 30161 Hannover, Germany Fax: +49 511 897668 29 | http://www.ivembh.de juergen.hunold(a)ivembh.de | | Geschäftsführer: Sitz des Unternehmens: Hannover | Univ.-Prof. Dr.-Ing. Thomas Siefer Amtsgericht Hannover, HRB 56965 | PD Dr.-Ing. Alfons Radtke

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[config] Sandia-pgi-11.9 thread support
by Vicente J. Botet Escriba 21 Dec '11

21 Dec '11

Hi, on the regression test I see this error Test output: Sandia-pgi-11.9 - thread - test_barrier / pgi-11.9 Rev 76060 / Mon, 19 Dec 2011 10:30:05 +0000 *Report Time: *Mon, 19 Dec 2011 21:30:12 +0000 Compile [2011-12-19 12:43:58 UTC]: fail "pgCC" -INLINE:none -Kieee -fpic -fPIC -gopt -Minform=warn -DBOOST_ALL_NO_LIB=1 -DBOOST_TEST_NO_AUTO_LINK=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -D__need_IOV_MAX -I".." -c -o "/scratch/kbelco/boost/results/boost/bin.v2/libs/thread/test/test_barrier.test/pgi-11.9/debug/threading-multi/test_barrier.o" "../libs/thread/test/test_barrier.cpp" "../boost/config/requires_threads.hpp", line 86: catastrophic error: #error directive: "Compiler threading support is not turned on. Please consult your compiler's documentation for the appropriate options to use" # error "Compiler threading support is not turned on. Please consult your compiler's documentation for the appropriate options to use" ^ 1 catastrophic error detected in the compilation of "../libs/thread/test/test_barrier.cpp". Compilation terminated. Is something missing in the boost/config/requires_threads.hpp file? Best, Vicente

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... broken with clang
by Beman Dawes 21 Dec '11

21 Dec '11

On Sat, Dec 17, 2011 at 6:42 AM, Andrey Semashev <andrey.semashev(a)gmail.com> wrote: >... All in all, I consider clang to be at a too early stage of development > to support it in the libraries. While I believe clang has a bright future, I'm afraid I agree with you. Clang's lack of support on Windows, including lack of installer, makes it hard for Windows developers to work with clang. Looking forward to the day when clang "just works" on Windows, --Beman

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[iostreams] #5908: failure to parse optional fields in gzip header
by Travis Abbott 20 Dec '11

20 Dec '11

Hi, I'm wondering if anyone with commit access can have a look at this ticket/patch I put in a few months ago: https://svn.boost.org/trac/boost/ticket/5908 This is technically a regression, as it did work in 1.40, but support for multiple compressed files within 1 stream was not. When that was added, some refactoring was done which introduced this new bug. I actually need support for both of those features, so I'd really appreciate any consideration that can be given to this bug. Thanks, Travis Abbott

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[Review Results:Algorithms] Boost.Algorithms is accepted
by Dave Abrahams 20 Dec '11

20 Dec '11

Having “reviewed the reviews” of Boost.Algorithms, I'm pleased to announce that it is unconditionally accepted. Congratulations to Marshall Clow! There were 5 yes votes and 1 no vote. The issues raised in all reviews were taken seriously by Marshall and recorded in the issue tracker at https://github.com/mclow/Boost.Algorithm I trust that Marshall will address the most important ones immediately, so I feel no need to place conditions on acceptance. Among the most important issues: https://github.com/mclow/Boost.Algorithm/issues/19 https://github.com/mclow/Boost.Algorithm/issues/18 https://github.com/mclow/Boost.Algorithm/issues/16 https://github.com/mclow/Boost.Algorithm/issues/15 https://github.com/mclow/Boost.Algorithm/issues/2 Thanks, everybody, for your participation! -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Home page needs updating
by Nevin Liber 20 Dec '11

20 Dec '11

"Ten Boost libraries are already included in the C++ Standards Committee's Library Technical Report (TR1) and will be in the new C++0x Standard now being finalized. C++0x will also include several more Boost libraries in addition to those from TR1." Seems a bit out of date... :-) Nevin :-) -- Nevin ":-)" Liber <mailto:nevin@eviloverlord.com> (847) 691-1404

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