February 2014 - Boost - lists.boost.org

GSoC: Who is taking on the responsibility as organization admin for Boost this year?
by Hartmut Kaiser 05 Feb '14

05 Feb '14

Sorry if I missed this information... Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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[modular-boost] Questions about development procedures and more
by Gennadiy Rozental 04 Feb '14

04 Feb '14

Hi, Trying to start using modular boost (and git for that matter). I have several questions about this. These are in no particular order: 1. Why does ./b2 headers on windows creates hardlink for each file instead of directories? The process takes forever. 2. What the story about cmake based build? What state is it in? Can I try it now? How? Can I help with anything to push this further? I got a bit of experience with cmake since last time I see n this discussed. 5. What the status of testing of the new tree? How is it setup? Where can I read it? Specifically I am interested in what being tested against what. 4. First command to switch to develop branch produces warning(?) ...\modular-boost\libs\test>git checkout develop Previous HEAD position was 954d3ab... Thread: merge [81791]-tools dir missing Branch develop set up to track remote branch develop from origin. Switched to a new branch 'develop' Should I worry? 5. After I switched to development branch headers directory still "points to" master branch files. Actually I am not sure what it points to now since master files are nowhere anymore. How should I switch headers? 6. What the corresponding action with git, which does what svn up from root of tree did before? What I am after is comamnd(s) which updates other libs, but keep my lib as is (maybe merge changes from other developers). If "git submodule update" is one of these commands, why does it takes forever on fresh just cloned boost tree? 7. How do I run the test which will check how my changes affect other libraries (their master branch at least). Should I just run the test from root in my local copy? How do I test against develop branch of other libs and develop branch of other libs against me? 8. Dependency specification. This actually a big question, which can be split into several: 8.1 Is there place where I can see "released versions" for particular library/submodule? 8.2. Is there way to tell which other boost submodules I depend on? 8.3 Can I specify specific release version I want to depend on (per submodule)? 8.4 Can I somehow only checkout/pull the submodules I depend on? 8.5 Can I check which submodules depend on me and checkout only those? 8.6 Is there place where I can see which submodule version constitute specific boost release? 9. One of the wiki pages refers to "git submodule summary" command. I do not understand what this command supposed to do. 10. How do I create private branch? IOW branch which is not publicized on github, but one I can share with the team? 11. This page is not clear to me: https://svn.boost.org/trac/boost/wiki/PostCvtMergePoint What do I need to do to merge my development branch into master, given that it is significantly differ now (at the time of svn->git conversion)? Thank you. Gennadiy

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SQL: next iteration of sqlpp11
by Roland Bock 04 Feb '14

04 Feb '14

Dear boosters, after the lively discussion about sqlpp11 in November 2013 (http://lists.boost.org/Archives/boost/2013/11/208388.php) sqlpp11 has evolved quite a bit and I want to give you an update. https://github.com/rbock/sqlpp11 *) sqlpp11 now supports prepared statements. For instance auto ps = db.prepare(select(all_of(tab)) .from(tab) .where(tab.alpha != parameter(tab.alpha))); ps.params.alpha = 42; for (const auto& row: db.run(ps)) { std::cerr << "alpha: " << row.alpha << std::endl; std::cerr << "beta: " << row.beta << std::endl; std::cerr << "gamma: " << row.gamma << std::endl; } *) Binding of parameters and results for binary transport is now supported. Both, parameters of prepared statements and results can be bound to in-memory data of the database now. In the example above, using the provided mysql connector, neither parameters nor the non-text results are converted to/from string. *) Support for multi-row insert: //First, you create an insert: auto i = insert_into(tab).columns(tab.alpha, tab.beta); //Then you add values (one or more times): i.values(tab.alpha = 7, tab.beta = "seven"); // Then you run the insert db.run(i); There is no support for array binding in sqlpp11, since this is highly vendor specific afaict. But it would be fairly easy to add support for this in the vendor-specific connector library. I'd be happy to support you if you wanted to give it a try. *) New interpreter for SQL expression trees: This has changed and improved a lot. sqlpp11 has been stripped of all vendor specific code and will serialize standard SQL. The connector libraries can specialize an interpreter template to change the representation of certain aspects. For instance, mysql would represent the concatenation of strings as CONCAT(a,b) instead of a||b. But of course, the connector libraries are not required to turn the expression into a string. They can interpret it any way they like. I strongly believe that this is going to allow for writing connectors to XML, input streams, maps, etc. (think LINQ). *) I added a sample code generator (in python) that generates table representations from a DDL Todo-List: ---------- *) More thorough documentation *) More thorough and easier to comprehend tests *) Some of you mentioned that Boost.Fusion or Boost.Preprocessor might do be able to do the job of code generation very elegantly. I won't do that myself but I'd be interested to see such solutions. Since code generation is not integral part of the library it would make sense to have such solutions as support libraries. *) Look into cursors FYI, I am going to give a talk about sqlpp11 and some template patterns used inside of it on February 27 in Munich, see http://www.meetup.com/MUCplusplus/events/160688442/ Please let me know your questions/thoughts/suggestions/rants. Contributions welcome, of course :-) Regards, Roland PS: Given enough interest, I intend to officially propose the library to boost (after several more iterations, of course). This is why I hope it is OK to discuss sqlpp11 on this mailing list every now and then.

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Regarding GSoC 2014
by shubhv＠iitk.ac.in 04 Feb '14

04 Feb '14

Hey, I am a sophomore student of Computer Science Department, IIT Kanpur, India. I have been going through the boost libraries for quite some time now, and also have read through the proposed GSoC projects in 2014. I am especially interested in the Boost.Math Generalized Hyper geometric Functions. Though I have gone through the links provided under that project and am trying to become versed with Boost's Math library, I am finding it difficult to find a starting point to contributing. I would be really glad if someone could help me in the initial phase by directing me to the right starting point and guide me through. Thanks Shubhangee Verma

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Trying modular Boost
by Paul A. Bristow 04 Feb '14

04 Feb '14

FWIW here are some things I didn't understand or did wrong. (And, of course, playing Devil's Decidedly Dumb Advocate ;-) 1 How do I know if I have the right version of Git? Open GitHub icon and check Tools/About? 2 Windows hint: If you install TortoiseGIT, avoid incompatibilities by using the command line version of Git that TortoiseGIT installs. I.E. place C:\Program Files (x86)\Git\cmd in your path ahead of any other git binaries, such as cygwin. Huh? Am I Shelling, Bashing, Batting or Powershelling? How do I do that? How do I check that I have done this right? Open a Windows command window? Many Windowers will not know how to find/edit their path (and should not need to know?). A link would help. If you have dozens of items in the path, this is pretty awkward to edit? But (after a frustrating failure to get SSH access to work - in a separate post) I got to the main course using https: https://github.com/boostorg/boost.git Submodule 'io' (https://github.com/boostorg/io.git) registered for path 'libs/io' Submodule 'iostreams' (https://github.com/boostorg/iostreams.git) registered for path 'libs/iostreams' <big snip> Cloning into 'tools/quickbook'... Submodule path 'tools/quickbook': checked out '340c65150d175ffc20a9a877247928b3ed5eba1b' Success (4040769 ms @ 31-Dec-2013 17:00:21) Just over an hour (using my nominal 10 mbps living-in-the-boondocks but line-of-sight radio link) - something that should be noted in the docs (along with a strong recommendation to send to a log file)? Other you would miss/lose this very useful info? Building the Boost C++ Libraries. Performing configuration checks - symlinks supported : no - hardlinks supported : yes - 32-bit : yes . And I could test system library OK J Phew! Paul PS I had an existing (luckily current) b2.exe at c:\program files\Boost and this is implicitly in my PATH. Do we need to be more specific about how b2 is stored and accessed? Some check that b2.exe vcvars32.bat etc are all set up correctly would be good? --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 <mailto:pbristow@hetp.u-net.com> pbristow(a)hetp.u-net.com

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Process for the Community Maintenance Team
by Marshall Clow 04 Feb '14

04 Feb '14

I’ve put up a set of procedures for the Boost Community Maintenance Team (CMT) on the wiki at: https://svn.boost.org/trac/boost/wiki/CommunityMaintenance Comments welcomed. — Marshall

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Udp Socket
by •°o.O sαмι O.o°• 04 Feb '14

04 Feb '14

Asalam-o-Aliakum and Hi all, I am having a problem with boost udp socket. My program terminates after throwing exception "host unreachable". My questions: 1). why udp socket cares for host it should just send data out of its own port and its job is done? 2). And how it knows that host is not available if udp is connection less protocol? 3). And another simple question how to avoid program termination on this exception? Best Regards; Sami Ul Haq

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Building with clang for Windows/MingW
by Edward Diener 03 Feb '14

03 Feb '14

When trying to test clang under Windows which is built with MingW, Boost Build runs with the options: -c -x c++ -O0 -g -fno-inline -Wall -g -mthreads However clang does not recognize -mthreads and flags it as an error. Is there anything I can do to remove this option from the clang++.exe command line when invoking Boost Build ?

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named_condition_any not working.
by Marius Adrian DOBRESCU 02 Feb '14

02 Feb '14

Hello! I tried to use into my code an interprocess mechanism like producer/multiple consumers with named_sharable_mutexes. I found out that named_condition_any is not working with any kind of scoped locks. Neither with sharable_mutex or simple named_mutex. It takes the lock successful but cannot unblock another process when notify is called. I used linux, gcc 4.8, just basic build, linking with pthreads. Is this a known issue to you because I couldn't find any info related on the Internet? Maybe I can take a look next week what is in there... Adrian

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http://lists.boost.org/Archives/boost/2014/01/211169.php
by Gilbert Polo 02 Feb '14

02 Feb '14

Thank you for the simple explanation. Somehow I lost sight of the forest for the trees or its a lot easier to see when the obvious is pointed out.

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