February 2014 - Boost - lists.preview.boost.org

[move] interest: the pass-by-value and swap idiom, and explicit copy constructors
by Krzysztof Czainski 20 Feb '14

20 Feb '14

Hello, I would like to ask about interest in an idea of mine. I described it in detail [1] and implemented it as part of my cz libraries [2]. In short, the idea presents: - an alternative to implicitly copyable and movable types: making them explicitly copyable; - a protocol for explicitly stating in code, where a copy is to be made (boost::copy()), which compliments the protocol for explicitly stating in code, where a move is allowed (std::move() or boost::move()); - a Boost.move extension for implementing movable types with use of the pass-by-value and swap idiom, backwards-compatible with C++98, which allows to choose copying policies (and eases changing between these policies during maintenance): - movable but not copyable, - movable and explicitly-copyable, - movable and copyable; - an example, showing how simply a CloneablePtr can thereby be implemented. This extension to Boost.move is hosted and developed as part of my cz libraries [2], but it isn't tied to them at all. It only consists of two headers. I extracted the two headers together with samples and docs, and they are available as a zip archive [3]. I would be most excited if there was interest in adding this functionality to Boost.move, but in any case, all comments are much appreciated. Regards, Kris [1] http://kristoczaj.bitbucket.org/cz/copy_move_types.html [2] http://kristoczaj.bitbucket.org/cz/index.html [3] http://bitbucket.org/kristoczaj/cz/downloads/move-0.7.1.zip

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[build] Headers rule does both too much and too little
by John Maddock 20 Feb '14

20 Feb '14

Folks I don't think the headers rule is working very well at present - it seems to both do too much and too little depending on the context: Too much: If I build the type_traits tests so everything is up to date, and then touch say type_with_alignment.hpp, then in libs/type_traits/test do: bjam add_const_test And for some strange reason bjam thinks there's a dependency on type_with_alignment.hpp from add_const_test, and there really isn't. In fact *every* test seems to be out of date now. Too little: The headers under boost/config/ are included via macros so aren't placed in the dependency graph. I can fix this easily enough in the Boost.Config tests, but ideally this should be fixed at the top level by making everything under boost/config/ a dependency of boost/config.hpp. This is currently causing some Boost.Config tests to fail in the online matrix, I bet there are others as well. Anyone any ideas? Thanks, John.

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[move] [range] move algorithm (was: interest: the pass-by-value...)
by Krzysztof Czainski 20 Feb '14

20 Feb '14

2014-02-15 1:05 GMT+01:00 Adam Wulkiewicz <adam.wulkiewicz(a)gmail.com>: > Hi, > > Krzysztof Czainski wrote: > >> 2014-02-14 18:16 GMT+01:00 Lars Viklund <zao(a)acc.umu.se>: >> >> On Fri, Feb 14, 2014 at 05:52:53PM +0100, Krzysztof Czainski wrote: >>> >>>> - a protocol for explicitly stating in code, where a copy is to be made >>>> (boost::copy()), which compliments the protocol for explicitly stating >>>> in >>>> >>> Note that boost::copy already exists as the widely used Range-based >>> complement of std::copy algorithm. >>> >>> I just want to get this out of the way so people can focus on the actual >>> proposal and not parrot this over and over again. >>> >>> Good point, thanks Lars. >> >> Note, that an algorithm boost::move also exists: >> http://www.boost.org/doc/libs/1_55_0/doc/html/move/move_algorithms.html >> And I'm not sure how a Range-based complement to the move algorithm could >> look like, but it may also turn out useful. >> > > Probably like this: > boost::move(range, out_it) ; > > Regards, > Adam Hmm, how about: boost::copy( range | movable, out_it ); Regards, Kris

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[Boost.Test] Assertion changes in trunk? [WAS: Call for Review: Boost.Test documentation rewrite]
by Dominique Devienne 19 Feb '14

19 Feb '14

On Wed, Jan 22, 2014 at 11:25 AM, Alexander Lamaison <awl03(a)doc.ic.ac.uk>wrote: > [...] As for as I'm aware, the only change is > to the assertion macros, which move to a more natural syntax: > > BOOST_CHECK_EQUAL(a, b) becomes BOOST_TEST(a == b) > BOOST_CHECK_LT(a, b) becomes BOOST_TEST(a < b) > ... etc. > BOOST_REQUIRE_EQUAL(a, b) becomes BOOST_TEST_REQUIRE(a == b) > ... etc. > BOOST_WARN_EQUAL(a, b) becomes BOOST_TEST_WARN(a == b) > But don't we then miss better messages which actually show the values themselves when the assert fails? I do BOOST_CHECK(a == b) only when a and b lack the op<<, but otherwise greatly prefer BOOST_CHECK_EQUAL(a, b). And what's the point of going from BOOST_REQUIRE(expr) to BOOST_TEST_REQUIRE(expr), i.e. make it longer / more typing? What am I missing? --DD

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Meeting C++ 2014 - Call for Papers
by Jens Weller 19 Feb '14

19 Feb '14

Hello boost community, Meeting C++ 2014 has been announced today, it will be in Berlin on the 5th and 6th December! More details on the conference in the official announcement: http://meetingcpp.com/index.php/newsreader/items/announcing-meeting-c-2014-… With the announcement, also the call for paper is now again open till April 20th. This years theme track of the conference is "Scientific Programming with C++". I'm looking for a diverse set of talks about C++, talks about boost, Qt, STL, any libraries, testing, the C++ language (C++11/14/1y) or any other C++ related topic. More details on the call for papers: http://meetingcpp.com/index.php/newsreader/items/call-for-papers-meeting-c-… Kind regards, Jens Weller

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[GSoC 2014] [ B-tree + Trie ]
by Cosmin Boaca 19 Feb '14

19 Feb '14

Hello, I am a second year BS student at Politehnica University of Bucharest and I am interested in contributing to boost during GSoC 2014. I would like to work at implementing the B-Tree data structure and continuing the work at the Trie data structure implemented in last year's gsoc. I would like to hear your opinion about this project and I would be glad to discuss with someone that is willing to be a mentor for it. Thank you, Cosmin Boaca

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[type_traits] Should namespace boost::align be namespace boost::detail::align?
by Glen Fernandes 18 Feb '14

18 Feb '14

I was working on a tiny library, Boost.Align, which would provide (among other things) a boost::align (that would be std::align if BOOST_NO_CXX11_STD_ALIGN is not defined, or a reasonably non-portable implementation otherwise) and found that type_with_alignment.hpp uses the identifier 'align' for a namespace within namespace 'boost'. Was this namespace intended to not be within boost::detail? If it can be, I'll send a pull request; if not, I'll choose a different identifier over 'align'. Glen

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Release script module
by Daniel James 18 Feb '14

18 Feb '14

Now that we have a separate module the release scripts we should remove them from the super project. I'll do that if there are no objections. Do we want to keep it as a submodule, or just completely separate? A lot of the scripts seem to be subversion specific, so can they just be deleted?

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[trac] Resolving tickets
by Ahmed Charles 18 Feb '14

18 Feb '14

https://svn.boost.org/trac/boost/ticket/9415 I've never used trac before and I'm trying to resolve this ticket, but I don't think I can. Do I need a 'trac id' to be able to resolve tickets? Or am I simply missing something?

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Re: [boost] Just another GSoC project idea: Create a Bjam clone based on the Boost libraries
by Brian Wood 17 Feb '14

17 Feb '14

Niall Douglas writes: > (My only request is that if you do do this, please stick a great big > auto-generated warning on the top of every bjam file output. I've got > nobbled by my build script changes getting eaten too many times in my > life!) I'm not sure. I generate both headers and source files. Currently in the headers, I have such a warning. But all of the generated files have a "zz." prefix. I could either put the big warning also in the source files or remove it from the header files. It seems to me that the naming convention might be enough of a warning. Also, I've liked the prefix since it groups the generated code together. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[Boost] [Config] Macros for the absence of a full C++11 <memory> implementation
by Glen Fernandes 17 Feb '14

17 Feb '14

Macros to determine the availability of C++11 functions in <memory> like std::align would be useful to me. (I know that declaration begs the inquiry "What conforming code would you write if std::align is not present?" but that is separate e-mail...) Would a BOOST_NO_CXX11_HDR_MEMORY be generally useful? Glen

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[graph] named_graph
by Jan Hudec 17 Feb '14

17 Feb '14

Hello, Looking for a way to add index of vertices by some id to adjacency_list graph I notices it derives from maybe_named_graph that should support this. However I didn't find any example nor really usable description of how to use it (I'd need to define boost::graph::internal_vertex_name, but I don't know what the typedef is supposed to be). Is there any code that uses this, anywhere? -- - Jan Hudec <bulb(a)ucw.cz>

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[sync] Included file not found
by Edward Diener 17 Feb '14

17 Feb '14

When I build boost libraries from the top with the latest modular-boost master with MingW/gcc-4.8.1 on Window I get thi error in sync: In file included from libs\sync\src\tss_windows_pe.cpp:9:0: ./boost/sync/detail/config.hpp:32:42: fatal error: boost/detail/winapi/config.hp p: No such file or directory #include <boost/detail/winapi/config.hpp> ^ I do not see this file anywhere. What is the issue and can this be corrected ?

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[thread] Errors when building wave
by Edward Diener 17 Feb '14

17 Feb '14

When building the Wave tool on the 'master' branch with gcc-4.8.1/MingW on Windows I am seeing these errors" ..\..\..\..\libs\thread\src\win32\thread.cpp: In static member function 'static unsigned int boost::thread::physical_concurrency()': ..\..\..\..\libs\thread\src\win32\thread.cpp:425:51: error: 'GetLogicalProcessor Information' was not declared in this scope GetLogicalProcessorInformation(NULL, &size); ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:429:21: error: 'SYSTEM_LOGICAL_PROC ESSOR_INFORMATION' was not declared in this scope std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> buffer(size); ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:429:57: error: template argument 1 is invalid std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> buffer(size); ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:429:57: error: template argument 2 is invalid ..\..\..\..\libs\thread\src\win32\thread.cpp:429:65: error: invalid type in decl aration before '(' token std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> buffer(size); ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:430:52: error: request for member ' front' in 'buffer', which is of non-class type 'int' if (GetLogicalProcessorInformation(&buffer.front(), &size) == FALSE) ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:436:25: error: invalid types 'int[s ize_t {aka unsigned int}]' for array subscript if (buffer[i].Relationship == RelationProcessorCore) ^ ..\..\..\..\libs\thread\src\win32\thread.cpp:436:43: error: 'RelationProcessorCo re' was not declared in this scope if (buffer[i].Relationship == RelationProcessorCore) ^ Does anybody know what I have to do to get this working ?

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Just another GSoC project idea: Create a Bjam clone based on the Boost libraries
by Boris Schäling 17 Feb '14

17 Feb '14

Create a Bjam clone based on the Boost libraries 1. Write a parser for the most important rules (exe, lib and so on) based on Boost.Spirit 2. Use the parser's actions to create a dependency tree based on Boost.Graph 3. Attach Python functions to the nodes in the dependency tree based on Boost.Python 4. Implement Python functions for one toolset (like g++) The project promises a lot of variety as different Boost libraries have to be used. It's also an opportunity to get familiar with various Boost libraries. As it can be broken down into tasks it shouldn't be that difficult to make a realistic plan for a summer project. If there is anyone interested have a look at <https://github.com/boostcon/2011_presentations/raw/master/mon/Boost.Build.p…> and <http://www.highscore.de/cpp/boostbuild/> for more information about the build system. And of course the idea is not to create a fully featured Bjam clone in a few months. If there is a binary at the end of the project which can build a software based on a simple Jamfile the project is a success. It's more important to have all the required components in place even if they are far from complete (but once they are in place it shouldn't be too difficult to extend them later and add support for another rule for example). Boris

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[container] Experimental support for memory expansion in vector and burst allocation in node containers
by Ion Gaztañaga 16 Feb '14

16 Feb '14

Hi to all, Some years later than I expected, I've committed to the master branch (after regression tests in develop were ok) a new feature for Boost.Container: new experimental allocators that support memory expansion and burst allocation in order to improve insertion and erasure times in most containers. The interface of these allocators is a variation of the interface I proposed in N2045. The interface is still experimental and not ready to be used by other containers as it's quite complex to handle and I think it can be further improved. Nevertheless, Boost.Container users can benefit from improved performance just using these allocators. The first experiment using this approach can be found in my old article "Applying classic memory allocation strategies to C++ containers" (http://www.drivehq.com/web/igaztanaga/allocplus/) In that article, Boost.Interprocess containers were modified to support N2045 and DLMalloc was version 2.8.3. In the new version the extended system allocator is based on DLMalloc version 2.8.6 (I've noticed a performance improvement in DLMalloc in the new version) and requires linking a new Boost.Container library. Boost.Container is still header-only if extended allocators are not used. DLMalloc is known to be size and speed efficient for non heavily multithreaded environments, but Boost.Container DLMalloc extension is *not* a replacement for multithreaded allocators (say ptmalloc2, ptmalloc3, nedmalloc, tcmalloc, jemalloc...). Your default system allocator will be more efficient than Boost.Container for highly multithreaded environments. On the other hand, at least in Windows and Linux, the allocator seems to be very efficient in non-multithreaded programs. The following extended allocators are provided: * boost::container::allocator: This extended allocator offers expansion, shrink-in place and burst allocation capabilities implemented as a thin wrapper around the modified DLMalloc. It can be used with all containers and it should be the default choice when the programmer wants to use extended allocator capabilities. * boost::container::node_allocator: It's a Simple Segregated Storage allocator, similar to Boost.Pool that takes advantage of the modified DLMalloc burst interface. It does not return memory to the DLMalloc allocator (and thus, to the system), unless explicitly requested. It does offer a very small memory overhead so it's suitable for node containers that allocate very small value_types and it offers improved node allocation times for single node allocations with respect to boost::container::allocator. * boost::container::adaptive_pool: It's a low-overhead node allocator that can return memory to the system. The overhead can be very low (< 5% for small nodes) and it's nearly as fast as boost::container::node_allocator. It's also suitable for node containers. More details on the implementation of this allocator can be found in http://www.drivehq.com/web/igaztanaga/allocplus/#Chapter3. The goal of these extended allocators in Boost.Container is to start building widespread existing practice in regularly requested features from container users (realloc-like behaviour in vector, amortizing several node allocation in range insertions, etc...). I'm not an allocator expert, nor a HPC guru. These new allocators are just the first step of an experiment that I hope real experts will improve. I will appreciate any comment, bug report or suggestion. Thanks, Ion

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Lost the Gmane interface
by Edward Diener 16 Feb '14

16 Feb '14

Normally I post to this list using the Gmane newsgroup interface. The last message I tried to send via this interface received the response from Gmane: "You have tried posting to gmane.comp.lib.boost.devel, which is a unidirectional mailing list. Gmane can therefore not send this message to that mailing list. " Does anybody know what is happening ? I sent a message to a Gmane administrator but so far no response. Edward Diener

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[intrusive] intrusive/detail/has_member_function_callable_with.hpp(74) : fatal error C1189: #error : "BOOST_PP_ITERATION_START() must be zero (0)"
by Vicente J. Botet Escriba 15 Feb '14

15 Feb '14

Hi, there is an issue in has_member_function_callable_with.hpp that make a lot of test fail. See for example the following compiler errors. Could this be fixed? Thanks, Vicente Test output: teeks99-02j-win2008-64on64 - thread - shared_future__copy_assign_p / msvc-12.0 Rev 085b21ee6f062cfc538438496cc5f6ac2da9217f / Fri, 14 Feb 2014 21:34:08 +0000 Compile [2014-02-15 04:21:38 UTC]: fail call "C:\Program Files (x86)\microsoft visual studio 12.0\vc\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"C:\local\teeks99-02\j\results\boost\bin.v2\libs\thread\test\shared_future__copy_assign_p.test\msvc-12.0\debug\threading-multi\sync\futures\shared_future\copy_assign_pass.obj.rsp" copy_assign_pass.cpp C:\local\teeks99-02\j\boost_root\boost/intrusive/detail/has_member_function_callable_with.hpp(74) : fatal error C1189: #error : "BOOST_PP_ITERATION_START() must be zero (0)" and Test output: teeks99-05f-Ubuntu12.04-64 - thread - async__async_p / clang-linux-3.0 Rev 91a3fc2ca12c3dfdf088383f8b60fb476e222039 / Fri, 14 Feb 2014 23:21:25 +0000 Compile [2014-02-15 02:19:03 UTC]: fail "clang++-3.0" -c -x c++ -Wextra -Wno-delete-non-virtual-dtor -Wno-long-long -Wunused-function -pedantic -O0 -g -fno-inline -Wall -pedantic -g -pthread -fPIC -Wextra -Wno-delete-non-virtual-dtor -Wno-long-long -Wunused-function -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED -DBOOST_THREAD_USE_DLL=1 -I".." -o "/mnt/teeks99-05/f/results/boost/bin.v2/libs/thread/test/async__async_p.test/clang-linux-3.0/debug/threading-multi/sync/futures/async/async_pass.o" "../libs/thread/test/sync/futures/async/async_pass.cpp" In file included from ../libs/thread/test/sync/futures/async/async_pass.cpp:34: In file included from ../boost/thread/future.hpp:54: In file included from ../boost/thread/detail/memory.hpp:18: In file included from ../boost/thread/csbl/memory/allocator_arg.hpp:16: In file included from ../boost/container/scoped_allocator.hpp:28: In file included from ../boost/container/allocator_traits.hpp:29: In file included from ../boost/container/detail/memory_util.hpp:30: In file included from ../boost/preprocessor/iteration/detail/iter/forward1.hpp:57: ../boost/intrusive/detail/has_member_function_callable_with.hpp:74:5: error: #error "BOOST_PP_ITERATION_START() must be zero (0)" #error "BOOST_PP_ITERATION_START() must be zero (0)" ^ ../boost/intrusive/detail/has_member_function_callable_with.hpp:305:44: error: no template named 'has_member_function_callable_with_allocate_impl'; did you mean 'intrusive::detail::has_member_function_callable_with_pointer_to_impl'? struct BOOST_PP_CAT( BOOST_PP_CAT(has_member_function_callable_with_ ^

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[GSOC] '14 web page minor typo
by zlynus 15 Feb '14

15 Feb '14

Hi all. I'm Lingyu Zhu, a student working on a GSOC proposal. First of all,Thanks to the admin that 2014 GSoC web page has so many great idea and they are all well-documented, especially the section describing the idea of improving boost.afio,which draw my special attention. However, there is a conspicuous typo in the header line: GGoogle Summer of Code 2014 =\ I wonder if the minor typo will effect google's judgement and thus the acceptance of boost org application. So here I am --this is my first 'bug report' ;) Best regards, Lingyu

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[utility] Missing current_function.hpp
by Edward Diener 15 Feb '14

15 Feb '14

From modular boost: switch to develop git pull git submodule update b2 headers No current_function.hpp anywhere switch to master git pull git submodule update b2 headers No current_function.hpp anywhere What am I missing ?

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NT² 3.0 and Boost.SIMD - Stable release
by Joel Falcou 15 Feb '14

15 Feb '14

The first stable release of the 3.x series of MetaScale’s open-source software is available: NT² 3.0. It also includes its spin-off project, Boost.SIMD (not yet a Boost library). Many Issues have been closed since last beta. The main focus of this release cycle was to fix performances issues and to stabilize some parts of the API. Next step will be to separate NT2 and Boost.SIMD into separate repositories, thus making one more step toward Boost.SIMD submission into review. [ http://www.metascale.org/nt%C2%B2-3-0-and-boost-simd ] *Changes & Bug Fixes:* - Major performance improvements in both libraries - Added experimental support for the HPX runtime for parallelization on shared memory systems - Optimizations of many elemental functions, in particuler log/ex, frexp/ldexp and cbrt - More advanced shuffle pattern recognition for SIMD - Fixed issues with Visual Studio 2013 - More functions are force-inlined to ensure good performance - New functions for conversion between types and mixing of vectors of different sizes - Demo applications usable as benchmarks - Better handling of errors when an unsupported function is called - New API for custom memory allocators Full changelog is available at https://github.com/MetaScale/nt2/releases/tag/3.0.0. *How to get it ?* - Source and binary packages can be downloaded here: http://nt2.metascale.org/downloads - The release is also available on Github : https://github.com/MetaScale/nt2/releases - The main master branch is still under development : https://github.com/MetaScale/nt2

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Refactoring tools/regression and tools/release into separate sub-modules
by Beman Dawes 14 Feb '14

14 Feb '14

The tools used by regression testers and regression reporting, and the tools used by release managers are currently part of the boost-super project. As we gain experience with Git and submodules, it is becoming clear these need to be decomposed into two separate submodules. Among other advantages, that would speed work on these tools as we could better utilize volunteers without having to hand out excessive super-project write permissions. We would like one or two volunteers to do the refactoring. You don't need to be a library maintainer or release manager, although that's fine if you are. You do need git skills, as we do want to preserve history. Comments? --The release managers

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Introducing Boost.Optional co-mantainer
by Fernando Cacciola 14 Feb '14

14 Feb '14

Hello, I am pleased to announce that Andrzej Krzemienski will be a co-mantainer for Boost.Optional His goal is to (finally!) implement: 1. Move semantics emulation (C++-3 compatible). 2. Function value() from tr2::optional that either returns a value or throws. For those of you who don't know Andrzej, he is the main force behind the standarizaztion of std::optional Once again, thank you very much Andrzej ! -- Fernando Cacciola SciSoft Consulting, Founder http://www.scisoft-consulting.com

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General Advice Thankyou - now I need a Trac login
by Fletcher, John P 14 Feb '14

14 Feb '14

Thank you for the helpful responses and a lot of new information. I now need a trac login and to be assigned as the maintainer for Phoenix. I have not found instructions for getting a Trac login. Please help. John

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path of test-binary
by dib 14 Feb '14

14 Feb '14

Hi, within the tests of a (not-yet) boost-library, how can I find out the path where b2 placed the binaries of the tests? Problem is the following: Some of the tests need the path to a shared library, which is built together with the tests. In the lib/mylib/tests/Jamfile.v2 I have the following: [...] # our test lib for shared library tests lib test_library : test_library.cpp ; test-suite mylib : # # shared library # [ run shared_library_load_test.cpp ] [ run shared_library_get_symbol_test.cpp ] # # [...] Inside shared_library_*_test.cpp I need something like this: boost::filesystem::path tstlib("bin.v2/libs/mylib/test/mycompiler/test_library.so"); As boost.build decides by itself where to put the binary, i cannot hardcode the path in the source-files.. Is there a way to get the path from boost.build? If not, how could I solve this problem? -- regards dib

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