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What does "xml this : this.qbk" do?
by Peter Dimov 21 May '15

21 May '15

Documentation Jamfiles often contain a line like xml core : core.qbk ; What does this line do? Is "xml" a rule? I haven't been able to find it anywhere.

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Questions about upcoming review of Boost.AFIO
by Niall Douglas 21 May '15

21 May '15

Dear list, Ahmed has volunteered to review manage AFIO (thanks Ahmed!), however I wanted to get the list's feedback on some things first. 1. After collecting feedback at C++ Now from members of WG21 on the shape and preferred future of a race free Filesystem TS, the next iteration of AFIO will have a radically different API consisting of the form: std::vector<afio::future<T>> afio::batch(...) afio::future<T> afio::async_io_handle::operation(inputs) noexcept(is_nothrow_move_constructible<T>) T afio::io_handle::operation(inputs) T afio::io_handle::operation(error_code &ec, inputs) The internal engine is the same very well tested code, just the API is very different from before. The current API was forced by VS2010's limitations and the lack of constexpr in MSVC - now VS2015 RTM has C++ 11 constexpr, I can adopt the custom future based API I always originally wanted. This new API will require C++ 14 in the compiler. Question: Given the API will so radically change, is now the time for a community review? Do note that APIBind allows me to support the existing API and the new API concurrently without issue. 2. AFIO requires APIBind which is a separate library. APIBind is not yet in the review queue and it is pending me writing up its documentation and a more useful unit test suite. Is this a problem? Do note that you the user of AFIO will never need to know about APIBind, it is entirely an internal implementation detail. Comments appreciated. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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More cool free github tooling: https://reviewable.io/
by Niall Douglas 21 May '15

21 May '15

Dear list, I'm not sure about other libraries, but in Boost.Thread Vicente the primary maintainer does the lion's share of dealing with pull requests but he occasionally needs someone else to review a patchset or a pull request before it can be merged. Github's facilities for this are okay - you can comment per line of a pull request, and overall. It works, though one wishes for something more gerrit like. So enter a new free tool with github integration: https://reviewable.io/. One click install into your github project. You now gain an alternative UI for pull requests, one which is much better than the default Github UI, specifically: * Per file review gating like gerrit * Can publish a group of per-line comments as a single thing (and just one email notification) * Doesn't hide deleted change history * Diffs are much better calculated and presented I've turned it on for AFIO. We'll see how it goes. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Some statistics about the C++ 11/14 mandatory Boost libraries
by Niall Douglas 21 May '15

21 May '15

Tomorrow at 11am after Eric's talk I'll be presenting at C++ Now a review of the upcoming C++ 11/14 mandatory Boost libraries. I looked at fifteen libraries and decided ten were worth further investigation. I'm sure you all remember my colour coded ranking of those ten libraries by "nearness" to entering Boost: https://goo.gl/6l1KiH I sadly only have time to review four of those libraries during my talk, but one (APIBind) enables an alternative Boost 2.0 approach and I will spend 45 mins on that library alone. And here is my alternative Boost 2.0 vision: Boost 2.0 is a alternative distro of modular standalone Boost libraries which can be each downloaded separately. Each has contemporary per commit CI testing and is nightly dashboarded by quality score by a web service under the 19 quality score headings listed at https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook (still unfinished, but nearly there). APIBind allows the library end user to dependency inject what dependencies that library uses. This allows a Boost library, in a single codebase, to be part of both the monolithic Boost 1.x distro and to be modular and standalone and part of the Boost 2.x distro. Motivated library maintainers port their Boost 1.x library to the APIBind platform, and therefore can be part of both 1.x and 2.x distros if they want. Those libraries not ported to APIBind remain in the 1.x distro, which I would assume will gradually fade into obsolescence over time. This makes sense, as if a maintainer is not motivated to do the port then it seems proper that library should gracefully deprecate. There is some empirical data supporting the inevitability of this alternative vision of Boost 2.0. Of the ten libraries I examined in any detail: * Just 1.5 libraries have any dependencies on Boost headers at all (the 0.5 is because that library is currently removing its Boost dependencies). * Just 3 libraries can use Boost.Test. * Just 3 libraries use Boost Docs. * Just 2 libraries require using Boost.Build. The rest are header only, or use cmake. * Just 6 libraries use Travis/Appveyor for free CI testing on Linux, OS X and Windows. * Just 3 libraries use valgrind as part of their unit testing (two are mine!). * Just 3 libraries use coveralls for coverage reporting (two are mine!). Personally speaking, I think the new library authors are overwhelmingly voting for a complete break with Boost 1.x. It makes no sense to bundle these new libraries into a 1.x monolithic distro when they have no dependencies on Boost. I believe now is the time we start establishing the infrastructure to shape the new Boost 2.0 distro instead of wasting resources on trying to refactor the 1.x distro. APIBind is there for maintainers wanting to be part of both distros. Let's make a clean break. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Deprecation Policy
by Rob Stewart 21 May '15

21 May '15

Some Boost libraries are unmaintained, some are under-maintained, and others have been replaced by newer libraries or by the Standard Library. Boost needs to decide whether to deprecate such libraries, and if so, how and when to do it. Please consider my initial thoughts below and provide ideas on such a policy. I will try to capture your ideas and create a policy statement for later review. It would seem obvious that unmaintained libraries should be deprecated, but a library that works, even if it has some known bugs, doesn't grow worse over time. Thus, if an unmaintained library was included in one Boost release, continuing to include it is no worse than before. That implies that deprecating Unmaintained libraries is not a given. Another issue is deciding when a library is unmaintained. Boost prefers that library authors and maintainers seek a replacement when no longer able to provide maintenance. Unfortunately, that doesn't always happen. Thus, establishing criteria by which to judge a library as unmaintained is warranted. Many continue to use C++03 and benefit from the presence of libraries that only support that language. I think it a non-starter to suggest that a library is unmaintained, or under-maintained, because it hasn't been updated to use C++11/14. Indeed, a replacement library may be the better way forward, while the old library might remain in Boost releases. Some have suggested that libraries with Standard Library equivalents be considered deprecated. Note that such libraries provide equivalent or similar functionality for older compilers, so I think that they should be treated the same as C++03-only libraries. Libraries that have superior replacements in Boost releases seem like obvious candidates for deprecation. There is precedent for that: Boost.Signals was deprecated in favor of Boost.Signals2. There are some likely libraries in this category, such as Boost.Lambda. Once we reach consensus on how to identify libraries to deprecate, we then must decide on the process. How long should a deprecated library be released before it is removed from Boost releases? How do we mark deprecated libraries? What do we do with deprecated libraries that have been removed from Boost releases? ___ Rob (Sent from my portable computation engine)

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[preprocessor] Link to Boostpro site for introduction to preprocessor metaprogramming
by Edward Diener 20 May '15

20 May '15

The preprocessor documentation has a link to the Boostpro site which had an html version of the Appendix A of "C++ Template Metaprogramming" by Abrahams and Gurtovoy. Appendix A is "An Introduction to Preprocessor Metaprogramming", which is all about Boost PP. Alas Boostpro is no more and the link in the preprocessor documentation goes nowhere. I can remove the link and any notice of the introduction. But If either David Abrahams or Aleksey Gurtovoy are still around it would be nice to get the html pages which existed before and incorporate them into the Boost PP docs. Does anyone know how to contact either of them ? I can try their addresses in maintainers.txt but I do not want to directly encroach on their privacy if there is a better way.

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Interest in non-intrusive signal/slot lib?
by Emil Dotchevski 20 May '15

20 May '15

Hello, I realize that Boost has Signals library already, but I've implemented a non-intrusive one which approaches the problem differently, and I'm pretty sure that there is no overlap between the two. It turned out more generic than I originally anticipated, so I thought I'd ask if others would find it useful as well. Specifically I was motivated by wanting to use Qt without MOCing. I asked the Qt community if that was possible which generated several rather annoyed negative responses. :) The issue is that while in Qt it's possible to use any function as a Slot, to define a new Qt signal for an existing Qt type one needs to derive from the Qt type, define the signal (as a member function) and do the MOC dance -- which I wanted to avoid. The result is a small, non-intrusive signals/slots library that allows objects of any type to be used as signal emitters, e.g. one of the included examples shows how signals can be emitted by a Windows HWND object. Documentation and source code released under the Boost license can be found here: http://www.revergestudios.com/boost-synapse/. Thanks, Emil P.S. Thanks to Peter Dimov for his feedback and for coming up with the name Synapse. :)

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Version mismatch on develop
by Peter Dimov 20 May '15

20 May '15

On the current develop, autolink wants to link to (for instance) libboost_filesystem-vc80-mt-s-1_59.lib, but b2 builds libboost_filesystem-vc80-mt-s-1_58.lib. That's because BOOST_VERSION has been updated to 1.59 in boost/version.hpp, but is still 1.58 in Jamroot.

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[type_traits] A bug in has_nothrow_default_constructor
by Andrzej Krzemienski 20 May '15

20 May '15

Hi All, I have submitted a new ticket: https://svn.boost.org/trac/boost/ticket/11324 Given the information floating around that Boost.TypeTraits are unmaintained and that they are to be replaced with the rewrite, is there any chance that this is fixed, or at least the test case added to regression matrix? BTW, does type_traits v2 handle this case correctly? Regards, &rzej

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[Testing] Android clang tests
by John Maddock 20 May '15

20 May '15

Since all the Android/clang tests which use PCH are failing, can we either: * Change the build options to disable PCH, or better, * Fix the clang toolset? Someone who understands clang on Android would have to do the latter. See http://www.boost.org/development/tests/develop/developer/output/CrystaX-NET… for an example fail. Many thanks, John.

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crash in boost/date_time/microsec_time_clock.hpp:70 v1.55
by George Georgiev 20 May '15

20 May '15

Hi, I am having crash in in local_time () at boost155_lin32_gcc480//include/boost/date_time/microsec_time_clock.hpp:70 I can call this in isolation and there is no issues, but in the production calls it crashes 100% reproducible with Program terminated with signal SIGABRT, Aborted. The only difference I could think about it is that the call is made from a dynamically loaded library. Is there any known issue about this? Thanks, George

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Getting a trac id
by Steven Ross 19 May '15

19 May '15

I have a bug filed against my library, but with no trac ID I can't modify the bug. How do I get a trac ID?

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RemoteCall framework for RPC
by Alex Marmer 19 May '15

19 May '15

Hello, I created a C++ framework RemoteCall which allows to use RPC the same way as local C++ calls are used. For declaration, implementation and call used macros: DECLARE_REMOTE, IMPLEMENT_REMOTE, CALL_REMOTE.Return and parameters (In and In/Out) can be any type except pointers. For instance: std::tuple<in, bool> DECLARE_REMOTE(Test)(std::vector<std::string>& vInOut, const std::wstring& sIn). Implementation is on https://github.com/amarmer/RemoteCall Would it be useful to add this framework in Boost? Sincerely,Alex

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[all][testing] Regression summary upgrades
by Adam Wulkiewicz 18 May '15

18 May '15

Hi, Recently the regression summary was upgraded. The cells corresponding to the failing tests can have names comp, link, run or fail. This way we can see what's the nature of the failure without going into details. See, e.g. the tests for Math: http://www.boost.org/development/tests/develop/developer/math.html The last category of failures (generic "fail") is for the others or unknown. Currently the "Lib" errors are falling into this category. There are some in Math, e.g.: http://www.boost.org/development/tests/develop/developer/output/CrystaX-NET… So we could mark them explicitly as "lib" failures and then the other/unknown failures could be marked as "unkn" or left as it is now - "fail". This has sense if there can be other "types" of failures, e.g. caused by some error in the testing scripts, Build or Regression, for which the reason is somehow unknown. Though I haven't seen them. I propose to go further with this and to mark the compilation failures for which we know the reason of the failure in a special way: - "file" - file too big (reported on Windows, e.g. http://www.boost.org/development/tests/develop/developer/output/MinGW-w64-4…) - "time" - time limit exceeded (e.g. http://www.boost.org/development/tests/develop/developer/output/teeks99-03b…) I saw them in many libraries and I think it would be very useful for libraries having many tests like Math or Geometry. The other types of failures I could think of aren't that important for me personally but maybe someone could appreciate them, e.g. the compilers developers: - "ierr" or "cerr" - internal compiler error or segmentation fault during compilation (e.g. http://www.boost.org/development/tests/develop/developer/output/PNNL-RHEL6_… or http://www.boost.org/development/tests/develop/developer/output/teeks99-03h…) - "segf" - segmentation fault during run (http://www.boost.org/development/tests/develop/developer/output/BenPope%20x…) Furthermore I propose to use various colors for different failure reasons. You can see the examples here: https://github.com/awulkiew/summary-enhancer https://github.com/awulkiew/summary-enhancer/tree/master/example/pages Of course the colors could be changed. We should be able to modify them in the master.css file. In the examples above they are varying much to make a clear distinction between them. But if you like the yelow collor then all of the new failures could be yelowish with a slight accent of another color, e.g. compilation errors could be yellow with orange accent and "time"/"file" errors with green accent. Regards, Adam

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Spirit 3.0.0
by Joel de Guzman 18 May '15

18 May '15

Hello! C++ Now 2015. Today is the official release of Spirit X3, aka Spirit 3.0.0. X3 will be in beta, coexisting side by side with Qi, Karma, Lex and Classic. If you are a Qi user. The best place to start are the examples, especially rexpr and x3 fun. Remember to use a compiler with c++14 capabilities: clang 3.4 or greater gcc 4.9 or greater Follow this link for more: http://boost-spirit.com/home/2015/05/16/spirit-3-0-0/ Cheers! -- Joel de Guzman http://www.ciere.com http://boost-spirit.com http://www.cycfi.com/

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[type_traits] Time to upgrade to "version 2" ?
by John Maddock 17 May '15

17 May '15

Now that the release is out it's decision time: I'd like to merge the "Version2" branch of type_traits to develop, it passes all the tests, and I've been using it exclusively for testing and development locally for a few months now without issues. But.... it's a big change with the potential to break a lot of folks stuff if things go wrong given that this is such a core component. To recap the main advantages are: * Removed all the redundant cruft that's no longer required for old/broken compilers we don't support anymore anyway. * Very nearly dependency free (other than Config), there's just comon_type which still has dependencies elsewhere - and even that disappears for a C++11 compiler. * Much cleaner, easier to understand code, now that the horrid obfuscating macros introduced by MPL have gone. * Fewer template instantiations than before as much of the indirection / forwarding templates have been removed. * As a result code using these headers should be somewhat faster to compile - both with fewer template instantiations, and a much lighter #include load. Note that as a result of this change, a number of undocumented headers which were none the less being used in Boost have been deprecated. The headers still exist, but warn loud and clear about their deprecated status, so folks will get a lot of warnings to begin with. I know Edward Diener has submitted some PR's to fix these, but I plan to make a concerted attack on any remaining once the new version is in develop. So here's the question, how do we proceed? My thoughts are to basically go ahead and merge, but not merge to master until after the next release at the earliest to give everything a chance to bed down, and the required changes in other libraries to filter through. Or we could have some sort of mini-review either formally or informally to check things out before the merge - of course folks are most welcome to do this anyway! Let me know what you think, best, John.

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[type_traits] difference in decay semantic between boost and standard library
by Anton Bikineev 17 May '15

17 May '15

Hi Boost, Is it expected semantic of boost::decay not to strip top-level constness? Thanks.

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[testing] Regression unresolved issues page
by Adam Wulkiewicz 15 May '15

15 May '15

Hi, The unresolved issues page seems to be outdated (only msvc-8.0 failures can be found there): http://www.boost.org/development/tests/develop/developer/issues.html It's because from all required toolsets mentioned here: https://github.com/boostorg/boost/blob/develop/status/explicit-failures-mar… only the msvc-8.0 is currently tested. The required compilers are quite old ones. I'm not sure how we should addres this issue. I get an impression that in the past this page was used differently than it is now. I'm not sure how though. The ToC/menu is also missing. Anyway, we could: - add only some specific, more modern required toolsets to the explicit-failures-markup.xml - ignore the required toolsets entries and display the issues detected in a library for all non-disabled toolsets - remove the issues page I'd probably go with the second option and treat this page as a complement of the regression matrix. What do you think? Regards, Adam

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[ELFIO] - New library proposal
by Serge Lamikhov-Center 15 May '15

15 May '15

Hello Boost community! I'd like to determine interest in possible new library submission. ELFIO is header-only C++ library that provides a simple interface for reading and generating files in ELF binary format. It is a mature library and is in use by a number of open source and commercial projects. It is a part of some Linux distributions as well as Cygwin project. Would you please have a look at the library's home page located at: http://elfio.sourceforge.net Documentation: http://elfio.sourceforge.net/elfio.pdf Library download: http://sourceforge.net/projects/elfio/files/ELFIO-sources/ELFIO-3.1/ and its source code available through: http://github.com/serge1/ELFIO Please share your opinion on making this library be a part of the Boost. Thank you and Best regards, Serge

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[test] Problem with BOOST_TEST_MESSAGE
by Edward Diener 15 May '15

15 May '15

In testing out a library with Boost.Test I want to inject informational messages that will appear in the output of the test results. When I use BOOST_TEST_MESSAGE with the correct logging level my message appears in the output if there is some sort of Boost.Test error during my tests. However if my unit test does not have a Boost.Test error my BOOST_TEST_MESSAGE does not appear. Needless to say I always want my BOOST_TEST_MESSAGE messages to always appear in the output. Is there a solution to this ?

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[website] Broken uBLAS link
by Renato Florentino Garcia 14 May '15

14 May '15

Hi, The link to uBLAS documentation page on http://www.boost.org/doc/libs points to http://www.boost.org/doc/libs/release/libs/numeric/ublas/doc/index.htm instead of http://www.boost.org/doc/libs/release/libs/numeric/ublas/doc/index.html There are a missing l on .html Regards, Renato Garcia

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[testing] Looking for test runner owner
by Andrzej Krzemienski 14 May '15

14 May '15

Hi All, The test matrix in branch 'master' contains these two test runners: oracle-intel-S2-stlport4 <http://www.boost.org/development/tests/master/oracle-intel-S2-stlport4.html> and oracle-sparc-S2-stlport4 <http://www.boost.org/development/tests/master/oracle-sparc-S2-stlport4.html> Could the owner of these reply to me? I am trying to fix a bug on this platform in Boost.Optional, and would require some assistance. Regards, &rzej

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[variant] 1.58 boost/variant/get.hpp compile errors
by Maarten de Vries 14 May '15

14 May '15

Hello list, I recently updated to boost 1.58 and one of my programs didn't compile any more. The reason was the <boost/variant/get.hpp> header. A simple test program and compiler output is attached below. Swapping the order of the includes or including <boost/type_traits/remove_cv.hpp> before <boost/variant/get.hpp> in the test program will get rid of the errors. It would appear that <boost/variant/detail/element_index.hpp> should include <boost/type_traits/remove_cv.hpp>. Kind regards, Maarten de Vries Test program: #include <boost/variant/get.hpp> > #include <boost/variant/variant.hpp> > > int main() { > return 0; > } > Compiler output g++ (GCC) 4.9.2 20150304 (prerelease): In file included from /usr/include/boost/variant/get.hpp:24:0, > from test.cpp:1: > /usr/include/boost/variant/detail/element_index.hpp:38:69: error: > ‘remove_cv’ in namespace ‘boost’ does not name a template type > variant_element_functor<boost::mpl::_1, typename > boost::remove_cv<T>::type > > ^ > /usr/include/boost/variant/detail/element_index.hpp:38:78: error: expected > template-argument before ‘<’ token > variant_element_functor<boost::mpl::_1, typename > boost::remove_cv<T>::type > > > ^ > /usr/include/boost/variant/detail/element_index.hpp:38:78: error: expected > ‘>’ before ‘<’ token > /usr/include/boost/variant/detail/element_index.hpp:38:88: error: template > argument 2 is invalid > variant_element_functor<boost::mpl::_1, typename > boost::remove_cv<T>::type > > > ^ > /usr/include/boost/variant/detail/element_index.hpp:39:9: error: expected > ‘::’ before ‘>’ token > > > ^ > /usr/include/boost/variant/detail/element_index.hpp:39:9: error: expected > identifier before ‘>’ token > /usr/include/boost/variant/detail/element_index.hpp:39:9: error: template > argument 2 is invalid > /usr/include/boost/variant/detail/element_index.hpp:40:5: error: expected > ‘::’ before ‘>’ token > > > ^ > /usr/include/boost/variant/detail/element_index.hpp:40:5: error: expected > identifier before ‘>’ token > /usr/include/boost/variant/detail/element_index.hpp:40:5: error: template > argument 2 is invalid > /usr/include/boost/variant/detail/element_index.hpp:41:1: error: expected > ‘::’ before ‘{’ token > {}; > ^ > /usr/include/boost/variant/detail/element_index.hpp:41:1: error: expected > class-name before ‘{’ token >

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Community Maintainence Team - a Modest proposal
by Robert Ramey 13 May '15

13 May '15

Today at 12:45 in Bethe is the operations meeting of the Boost Community Library Maintainence team. In advance of that meeting I'd like to render my proposal on this list so I have it written down. Premise:The library maintainence team does not and will likely never have sufficient resources to maintain libraries without current maintainers. Proposal: a) The CMT will solicit volunteers to take over maintainence of specific libraries. b) The most likely source of such volunteers are those working in companies which use and depend upon the libraries in maintainence. Such companies will be expected to support the library maintainence by permitting the maintainer to undertake this effort using company time and resources. c) Since we don't have a list of which companies are using which libraries, we will send a solicitation to volunteer to every person who has posted a bug report for the library in question on the TRAC system. I believe this is the most likely source for prospective maintainers. d) Companies that support maintainence of a particular library will be permited to place their logo and link on the TRAC page for that library. So they will receive the following benefits from sponsoring the maintainece of the library. 1) They will be demonstrating their commitment to the high standard of software development that Boost supports. 2) By placing their logo and link on the track page, they will be encouraging and facilitating prospective employees who desire to work for such an organization to contact them. That is, they will have a leg up on attracting the highest quality C++ programmers. 3) They will be guarenteed timely and rigorous maintainence of the library which they depend on. 4) They will have the inside track on proposing and implementing any library enhancements that they desire. 5) They will benefit from collaboration of the boost community which provides numerous valuable benefits: Bug fixes submitted by users, suggestions for enhancements. etc. The value of all these benefits to the sponsoring company will far, far out weigh the incremental cost of the employee time. In many cases, since employees have to maintain the library anyway - the incremental cost is zero anyway. This moves the responsibility for library maintainence to those most willing and able to undertake it. The role of the CMT would be to promote, recruit, certify, and monitor library maintainence. The CMT would have the authority to move the responsability from maintainer to another. The current practice of having a single person/entity responsible for maintainence of a library would continue unchanged. Robert Ramey

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boost serialization and new archive types
by Robert Ramey 13 May '15

13 May '15

I'm here at C++Now and some have approached me about some enhancements to the serialization library. Specifically there is interest in moving the implementation of XML serialization to the latest C++11 of boost. I've gone them one better - While they're at it, how about including JSON and YAML as well? I would be happy to meet with anyone and everyone interested in this while here at the conference. I'm commited to all the operations meetings 12:45 so that time would be out - I'm flexible. Robert Ramey

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