November 2014 - Boost - lists.boost.org

A GUI Library
by jinhao 09 Nov '17

09 Nov '17

Hi, all I am developing a GUI library, it takes aim at easy-to-use and portable library for modern C++ methods. The project at http://stdex.sourceforge.net A git repository at http://nanapro.codeplex.com A brief at http://nanaproject.wordpress.com/2011/12/16/preliminary-study-of-nana-c-lib… Is there any interest in this library? Regards Jinhao

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bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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[context] msvc /SAFESEH
by Jeff Flinn 12 Aug '15

12 Aug '15

I need to build my application with /SAFESEH which uses boost coroutine which uses context. I'm getting the following link errors: 1>libboost_context-vc100-mt-gd-1_53.lib(jump_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. 1>libboost_context-vc100-mt-gd-1_53.lib(make_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. I've built boost static libs with the same MSVC vesion and options (sans /SAFESEH as it's not a compile/lib option) Compiler/linker versions: Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86 Microsoft (R) Incremental Linker Version 10.00.40219.01 Has anyone run into this and resolved the error? Any insight is appreciated. Thanks, Jeff

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Arguing about names in Boost libraries
by Edward Diener 06 May '15

06 May '15

What is wrong with the people commenting on libraries for Boost who are so concerned about the names being used ? We are talking only about C++ identifiers and yet there are now endless discussions where people disagree on names or argue that some name is not what they want or that they like some other name, with a list of names that they find adequate. This is irrelevant. There is something mentally wrong about all those peoples spending endless amounts of time around this issue. I notice this does not happen nowadays for just one library but for ever single library, or proposed library, which is mentioned on this mailing list. Is this the way all of you people actually work in your daily jobs, or on your own projects, spending hours and days arguing with others about C++ identifiers for every little thing ? Are you not aware of the absurdity of your endless remarks ? Grow up ! Surely there are better things to do than carry on endlessly about some name, that is should be x or y or z or some other inane preferable list. It's time for somebody to say this, so I will do it. A C++ identifier name, as long as it is vaguely about what the functionality entails, is perfectly adequate. It does not have to satisfy everyone in the universe. Period !

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[build] b2 headers broken?
by Eric Niebler 02 Mar '15

02 Mar '15

I just updated to the latest develop. I ran bootstrap, then nuked my boost directory and reran b2 headers. Worked fine. Then I changed directory to libs/proto/test and ran ../../../b2 mem_ptr to run a test. Here's what I get: f:\modular-boost\libs\proto\test>..\..\..\b2 mem_ptr Performing configuration checks - symlinks supported : no - junctions supported : yes - hardlinks supported : yes ...patience... ...patience... ...found 4951 targets... ...updating 441 targets... common.mkdir ..\..\..\bin.v2\libs common.mkdir ..\..\..\bin.v2\libs\proto common.mkdir ..\..\..\bin.v2\libs\proto\test common.mkdir ..\..\..\bin.v2\libs\proto\test\mem_ptr.test common.mkdir ..\..\..\bin.v2\libs\proto\test\mem_ptr.test\msvc-12.0 common.mkdir ..\..\..\bin.v2\libs\proto\test\mem_ptr.test\msvc-12.0\debug common.mkdir ..\..\..\bin.v2\libs\proto\test\mem_ptr.test\msvc-12.0\debug\link-static common.mkdir ..\..\..\bin.v2\libs\proto\test\mem_ptr.test\msvc-12.0\debug\link-static\threading-multi link.rm ..\..\..\boost\mpl common.mkdir ..\..\..\boost\mpl link.hardlink ..\..\..\boost\mpl\print.hpp Hardlink created for ..\..\..\boost\mpl\print.hpp <<===>> ..\..\mpl\include\boost\mpl\print.hpp <snip> link.rm ..\..\..\boost\numeric\conversion link.hardlink ..\..\..\boost\numeric\conversion\conversion_traits.hpp The system cannot find the path specified. if exist "..\..\..\boost\numeric\conversion\conversion_traits.hpp" del "..\..\..\boost\numeric\conversion\conversion _traits.hpp" mklink /H "..\..\..\boost\numeric\conversion\conversion_traits.hpp" "..\..\numeric\conversion\include\boost\numeric\ conversion\conversion_traits.hpp" ...failed link.hardlink ..\..\..\boost\numeric\conversion\conversion_traits.hpp... link.hardlink ..\..\..\boost\numeric\conversion\int_float_mixture_enum.hpp The system cannot find the path specified. For some reason, b2 thinks it needs to rerun b2 headers, but it does a crap job of it and dies. What's going on? Eric

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Interactive metaprogramming shells
by Abel Sinkovics 28 Dec '14

28 Dec '14

Hi, I've built interactive shells for preprocessor and template metaprogramming. I've been using them for development and debugging of metaprograms and I think Boost developers could also find them useful. You can type in (metaprogramming) expressions which get evaluated and the result is displayed immediately. For example you can type boost::mpl::push_front<boost::mpl::vector<int, char>, double>::type and you get boost_::mpl::vector<double, int, char> as the result (the boost_ namespace is used because there are some tricks there to make the output more readable). As an example for the preprocessor shell you can type BOOST_PP_REPEAT(3, foo BOOST_PP_TUPLE_EAT(3), ~) and you get foo foo foo as the result. The tools are based on the Boost.Wave library and Clang. You can get them here: Preshell for preprocessor: https://github.com/sabel83/preshell Metashell for template metaprograms: https://github.com/sabel83/metashell You can also try them from your browser here: http://abel.web.elte.hu/shell Feedback is welcome. Regards, Ábel

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IDE for developing Boost
by Jens Müller 20 Dec '14

20 Dec '14

Hi, I am looking for recommendations for developing Boost, especially code in the graph library. At work, most developers (not for Boost, for some commercial software), most developers are using Eclipse. This works quite fine as soon as it has properly auto-discovered include paths etc. But before fiddling around with Eclipse to get all the settings right, I'd wanted to to ask for your recommendations. And maybe there are already settings available to make it "just work", at least initially. Cheers, Jens

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file_descriptor::read() docs?
by Olaf van der Spek 19 Dec '14

19 Dec '14

Hi, Where is file_descriptor::read() documented? Shouldn't it be at http://www.boost.org/doc/libs/1_57_0/libs/iostreams/doc/classes/file_descri… ? -- Olaf

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File Handle and FILE* wrappers?
by Olaf van der Spek 16 Dec '14

16 Dec '14

Hi, Would there be any interest in wrappers for file handles / descriptors and FILE*? Sometimes one needs native handles or FILE* for interoperability or special features like memory mapped IO, but standard C++ doesn't provide convenient RAII friendly wrappers for these. The idea seems trivial yet quite useful. I'm aware of <boost/iostreams/device/file_descriptor.hpp> but it seems to be too high-level. I've put a simple start for FILE* at https://code.google.com/p/xbt/source/browse/trunk/xbt/misc/xbt/cfile.h What do you think? Also posted at https://groups.google.com/a/isocpp.org/forum/#!topic/std-proposals/Q4RdFSZg… -- Olaf

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[utility] What happened to OptionalPointee/compare_pointees?
by Mostafa 16 Dec '14

16 Dec '14

1) OptionalPointee/compare_pointees reside here: libs/utility/OptionalPointee.html, but there's no way to navigate to it from here: libs/utility/ or here: libs/utility/utility.htm 2) IMO, compare_pointees should have stand alone documentation, and be grouped with pointee and indirect_reference. 3) pointee and indirect_reference are not iterator specific, therefore they shouldn't reside under iterator's documentation. IMO, compare_pointees, pointee and indirect_reference should all reside under a pointee utilities section. Thanks.

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[safe_numerics] questioning the basic idea
by Andrzej Krzemienski 15 Dec '14

15 Dec '14

Hi, I was going through the Safe Numerics library in Boost Library Incubator, and I realized I disagree with the basic idea it is built on. I wanted to rise my concerns here. If I were to summarize in one sentence what this library is, I would say: a drop-in replacement for type int that checks for overflow in run-time and throws an exception if it finds one. Did I get it right? The remainder of this post is based on this interpretation. If so, I am not sure if this idea is a good one and worth promoting in Boost. BTW this is one of my criteria for letting a library into Boost: whether it promotes worthy ideas. I agree with the statement that a program should be UB-free. But I do not think that the approach of letting the programmer do what he did before, having the library or some run-time tool check for potential UB, and throwing an exception instead makes the program any better (or safer). It is just hiding the symptoms but not curing the disease. The programmer should not plant the UB in the first place - I agree. But this is different than first doing the mess and then having the run-time clean it up for you. I know it works for many people, in a number of languages, and it may even be considered a practical solution, but (by inclusion into Boost) I wouldn't like to be sending the message "this is how you are suppose to code". I try to recall how I use type int. I do not think I ever use it for anything that would be close to "numeric" as I know the term from math. Use Case 1 (an index): for (size_t i = 0, I = v.size(); i != I; ++i) { if (i != 0) str += ","; str += v[i]; } There doesn't appear to be a good reason to wrap it into safe<int> here, even though the incrementation could possibly overflow. Plus, it would kill my performance. Use Case 2 (using reasonably small range): I used an int to represent a square on a chessboard. There is only 64 squares, so I couldn't possibly overflow, on whatever platform. And even if there exists a platform where 64 doesn't fit into an int, I would not use safe<int> there. I would rather go for something like double_int. If I were to use some numeric computations on integers and I perceived any risk that I may overflow, I would not be satisfied with having the computations stop because of an exception. I would rather use a bigger type (BigInt?). I do not think int is even meant to be used in numerical computations. I believe it is supposed to be a building block for building more useful types like BigInt. One good usage example I can think of is this. After a while of trying to chase a bug I comae up with a hypothesis that my int could be overflowing. I temporarily replace it with safe<int> and put a break point in function overflow() to trap it and support my hypothesis. I would probably use a configurable typedef then: #ifndef NDEBUG typedef safe<int> int_t; #else typedef int int_t; #endif But is this the intent? But perhaps it is just my narrow perspective. Can you give me a real-life example where substituting safe<int> for int has merit and is not controversial? I do not mean the code, just a story. Regards, &rzej

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List of C++ 11 only Boost libraries and their status?
by Niall Douglas 13 Dec '14

13 Dec '14

For C++ Now 2015 I am intending to present an overview of C++ 11 only Boost libraries in the review queue or very near the review queue by the time of the conference. I'd appreciate help filling in missing gaps in this list: * Boost.Spirit X3 ETA to Boost review: unknown, last commit was June 2014. * Boost.Proto 0x ETA to Boost review: unknown, last commit was Oct 2013. * Boost.Hana ETA to Boost review: Summer 2015, last commit was today. * Boost.AFIO ETA to Boost review: Already in review queue, last commit was two days ago. * Boost.BindLib ETA to Boost review: Q1 2015, last commit was two days ago. * Boost.Spinlock ETA to Boost review: Q2 2015, last commit was four days ago. * Boost.KernelAlloc ETA to Boost review: Q1 2015, last commit was today. * Boost.Expected ETA to Boost review: no later than Summer 2015 probably much earlier, last commit was two weeks ago. * Boost.CRUX ETA to Boost review: hopefully by end of 2015, last commit was three days ago. I have to admit surprise at how long the list I have collected already is. Are there any other C++ 11 only Boost libraries I am missing, or have I got the ETAs wrong? Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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[coroutine] x86 msvc11 stack corruption
by Tobias Loew 12 Dec '14

12 Dec '14

Hi, I use Boost 1.55 uni-directional coroutines to build an x86 MSVC11 application. I have a simple pull-type (boost::coroutines::coroutine<void>::pull_type) that under certain reproducable conditions destroys the stack after returning from the coroutine. Here is the corrupted stack as shown by VS2012 > ebs2000.exe!CScriptMainFrame::DoRun(CPascalEditorDoc * 0x00000000, int 0x00000000, int 0x00000000) Line 3372 C++ ebs2000.exe!CScriptMainFrame::OnDebugStepover() Line 4916 C++ mfc110u.dll!_AfxDispatchCmdMsg(CCmdTarget *, unsigned int, int, void (void) *, void *, unsigned int, AFX_CMDHANDLERINFO *) C++ 00000002() Unknown [Frames below may be incorrect and/or missing] mfc110u.dll!CCmdTarget::OnCmdMsg(unsigned int, int 0x00000000, void *, AFX_CMDHANDLERINFO *) Line 364 C++ mfc110u.dll!CWnd::OnCommand(unsigned int 0x00018263, long 0x00000000) Line 2785 C++ mfc110u.dll!CFrameWnd::OnCommand(unsigned int 0x00018263, long 0x00000000) Line 389 C++ ... This only happens in windows x86 32-bit release-builds when the coroutine finishes upon a user-action that also includes a windows WM_SETFOCUS message on my menu-bar. If at least one of the following is true, the stack-corruption does NOT happen: - debug-build - x64 build - using a different pull-type, e.g. enum status_enum{...}; boost::coroutines::coroutine<status_enum>::pull_type - not returning form the coroutine, but pushing just before the end of the coroutine and swapping the pull-type-variable with a default constructed "not-a-coroutine" Even though I have a lot of workarounds, I still would like to know, why this happens. regards Tobias PS: I had to recompile ml /safeseh /c make_i386_ms_pe_masm.asm ml /safeseh /c jump_i386_ms_pe_masm.asm to get SAFESEH-libraries. -- View this message in context: http://boost.2283326.n4.nabble.com/coroutine-x86-msvc11-stack-corruption-tp… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[review] Last day for formal review for Sort library
by Edward Diener 12 Dec '14

12 Dec '14

Today is the last day for the formal review of the Sort library by Steven Ross, which started November 10. We have had some great discussions and reviews so far and I would like to thank everybody involved, but as always we need more formal reviews. If you need any delay for your review after today, please contact me at 'eldiener at tropicsoft dot com' and I will take your review into account if given within a reasonable period of time after today. About the Sort library ================== The Sort library is a library which implements hybrid sorting algorithms based on a Spreadsort ( http://en.wikipedia.org/wiki/Spreadsort ), of which the author of the library, Steven Ross, is the inventor. The algorithm provides a sort that is faster than O(n*log(n)). The library provides a generic implementation of high-speed sorting algorithms that outperform those in the C++ standard in both average and worst case performance. These algorithms only work on random access iterators. They are hybrids using both radix and comparison-based sorting, specialized to sorting common data types, such as integers, floats, and strings. These algorithms are encoded in a generic fashion and accept functors, enabling them to sort any object that can be processed like these basic data types. Where to get it =============== The library is available on github at https://github.com/spreadsort/sort. The library is in modular Boost format and can be cloned to libs/sort under your local modular boost directory. I have provided as the review manager online documentation at: http://eldiener.github.io/sort Review guidelines ================= Reviews should be submitted to the developer list (boost(a)lists.boost.org) preferably with '[sort]' in the subject. Or if you don't wish to for some reason or are not subscribed to the developer list you can send them privately to me at 'eldiener at tropicsoft dot com'. If so, please let me know whether or not you'd like your review to be forwarded to the list. For your review you may wish to consider the following questions: - 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? And finally, every review should attempt to answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Even if you do not wish to give a full review any technical comment regarding the library is welcome as part of the review period and will help me as the review manager decide whether the library should be accepted as a Boost library. Any questions about the use of the library are also welcome.

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Review request for Compute
by Antony Polukhin 10 Dec '14

10 Dec '14

Hi, Please add the the Compute library to the review schedule. Compute is a GPU/parallel-computing library for C++ based on OpenCL. Author: Kyle Lutz Source code: https://github.com/kylelutz/compute Documentation: http://kylelutz.github.io/compute/ Review Manager: Antony Polukhin Approximate review date: end of November - December 2014 -- Best regards, Antony Polukhin

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Boost People section largely outdated
by Joaquin M Lopez Munoz 09 Dec '14

09 Dec '14

Hi, It is a pity that the Boost People section: http://www.boost.org/users/people.html is so outdated: many people there are no longer around, and, more importantly, many (most) current contributors are not listed. This is is a reminder for people to get themselves on that page! Instructions at http://www.boost.org/development/submissions.html#People Best Joaquín M López Muñoz Telefónica

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[mpl] [build] [testing] Merge pull requests
by Andrey Semashev 08 Dec '14

08 Dec '14

Hi, There were a lot of discussions about MPL recently, and I created a few pull requests to address issues: https://github.com/boostorg/boost/pull/39 Invoke 'headers' target before building testing tools. Note that several testers are currently failing to run because of this problem. Since this affects the testing process, I'd appreciate if someone familiar with it could take a look. https://github.com/boostorg/boost/pull/38 Add MPL.Core tests to the test report. These tests are currently not run by testers. https://github.com/boostorg/mpl/pull/12 Move a misplaced header from MPL to MPL.Core to resolve circular dependency between the two. I believe the first PR is especially critical. Could someone with permissions merge these? Thanks.

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Re: [boost] [optional] operator<(optional<T>, T) -- is it wrong?
by Felix Uhl 05 Dec '14

05 Dec '14

David Stone wrote: >I have been bitten in the past by operator<. I was converting code that >used unsigned with a 'magic value' to represent nullness to >boost::optional<std::uint32_t>. However, the maximum value it used was >std::numeric_limits<std::uint32_t>:max(). A simple find and replace for >this magic constant (which was referred to everywhere as DWORD_NULL) with >boost::none and fixing compile errors led to some erroneous code. We had >code that assumed an 'uninitialized' std::uint32_t was greater than any >valid value. >The concept of "value not present" is not inherently less-than or >greater-than any value, but because of operator<, code compiled that >shouldn't have. I suppose this is really an argument against any operator< >overload, not just the mixed-type comparison. I don't expect this to be a >major problem for new code, but there is a lot of code out there that uses >a magic value, and that is what optional is supposed to replace. I was irritated by it at first, too, and if you think about it the comparison brakes down to a philosophical problem: If I have a pair of pants and you don’t, are my pants smaller than yours? Hard to say, but to me the most logical solution is “no”. My pants aren’t smaller than yours, and my pants aren’t larger than yours. Also, your and my logic would apply to both the operator<(optional<T>, T) and operator<(optional<T>, optional<T>), but I think we’re only talking about the latter. --- Felix Uhl

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[review] [sort] Sort library review manager results
by Edward Diener 05 Dec '14

05 Dec '14

This is the results from the recent review of the Sort library of Steven Ross. First I would like to thank all those who made comments during the review, whether or not they officially gave a final Yes or No vote to whether the Sort library should be accepted as a Boost library. This list includes: Niall Douglas, Julian Gonggrijp, Phil Endecott, Vladimir Prus, Mathias Gaunard, Jeremy Murphy, Peter Dimov, Robert Ramey, Adam Walling, Anthony Polukhin, Phil Endecott, Paul Bristow, Thijs (M.A.) van den Berg Dupuis Etienne, and Frank Gennari If I have missed anyone I do apologize. Secondly I would like to thank Steven Ross for patiently answering all of the review comments to the best of his ability. My tally of Yes and No votes for acceptance are: Yes votes (5) : Niall Douglas ( conditional ), Julian Gonggrijp ( conditional ), Frank Gennari, Phil Endecott, Paul Bristow. No votes (3) : Vladimir Prus, Adam Walling ( conditional ), Anthony Polukhin I believe the condtional Yes vote from Julian Gonggrijp was completely met in the discussions of issues with Steven Ross and the conditional Yes vote from Niall Douglass was almost completely met in the discussion with Steven Ross about the issues mentioned, and enough to maintain his Yes vote. I want to also mention that the conditional No vote by Adam Walling has an implied Yes vote to it if the Sort library were one among other sort implementations. Since my final decision is not entirely based on the Yes and No votes I want to adumbrate some of the major issues brought up by the review without necessarily focussing on every one of the people who brought them up initially, as well as my own reactions to them as Review Manager. 1) The first major issue was whether a library whose basic merit lies in its algorithm and its speed/space constraints needs better theoretical backing. A number of reviewers discussed this after it was brought up. I tend to agree with reviewers that while the best theoretical basis is always desirable, it is not necessary for a Boost library whose empirical evidence can be and has been measured by its implementor and can be measured by any user. Furthermore Steven Ross has provided an extensive discussion in his documentation, as well as his original paper, about the theoretical merits of his technique. While much of this discussion is probably beyond the understanding of any but sorting experts and afficionados enough of it adequately explains the basic ideas behind SpreadSort for those who understand and have knowledge of basic sorting ideas and popular sorting techniques. 2) An important issue is the need for the Sorting library to provide extensive timing charts/tables comparing SpreadSort to at least std::sort ( and possibly other popular mainstream sorts ) with both different numbers of sort keys and different initial unsorted distributions. Steven Ross has been providing these charts/tables in the 'develop' branch of the library. 3) Connected to the previous issue is that a number of reviewers asked for better documentation on the conditions in which SpreadSort will show a marked improvement in speed compared to std::sort, as well as any condition(s) where SpreadSort performs worse than std::sort. While Steven Ross has explained that generally SpreadSort will fall back to using std::sort for some cases ( low N ), I too feel that the documentation needs to be more extensive for the average user in attempting to delineate the conditions where SpreadSort works best. 4) A really important issue discussed by a number of reviewers involves the creation of a synthetic radix, where most users of sorting algorithm are used to comparison based sorting functors. While the documentation provides information on the various individual sorts, as well as examples, I also feel that a discussion in the documentation of how to use SpreadSort when sorting structs/classes with multiple keys of different types would be invaluable. In other words, what and if are the common techniques for using SpreadSort with complicated keys which, when using comparison-based sorting, can be represented fairly easily be a functor. 5) Niall Douglass brought up the issue of exception guarantees when using SpreadSort, and I concur. The documentation should be stronger specifying what happens during the sorting algorithms if an exception occurs and/or does the sorting algorithm itself ever throw any exceptions and, if so, under what conditions. Steven Ross mentioned that he is adding exception guarantee information to his docs. 6) Many reviewers did not like the idea that the library should be called Sort when it is basically implementing a single sorting algorithm called SpreadSort. Alternate suggestions are: a) The library should be called SpreadSort. b) The library can be called Sort only if other sorting algorithms are added to it. c) The library can be called Sort with the proviso that it serves as a general library for sorting algorithms potentially added to it in the future. d) The library should be part of the Boost Algorithm library. Steven Ross mentioned other potential sorting implementations as part of the Sort library, under that general name, but all providing a good deal of extra work. These included a copy-based stable sorting algorithm, an LSD radix sorting, and an OpenMP based parallel implementation. Other reviewers mentioned some of the same types of sorting implementations and a few reviewers remarked that they also have created sorting implementations of their own. While I will give my own view at the end, I would like to mention here that I strongly believe that each sorting implementation needs to be reviewed separately for acceptance into Boost and never automatically added to a general library, whether it be called Sort or Algorithm or whatever. 7) Random issues brought up in comments I will mention, which have importance but which I do not believe are absolutely intrinsic yet still might be considered. a) C++11 techniques in general and inline namespaces in particular. b) A version that can work with less than random access. c) Optimizations for small sets of data ( Steven Ross has already addressed this to an extent in the 'developer' branch of the library ). d) Possible documentation of using SpreadSort as a subsort for parallel sorting techniques and possible discusion in the docs about Spreadort and parallel sorts. e) General O() information in docs. f) SpreadSort examples hoisted directly into docs using Quickbook technique and updating the Spreadort docs to use Quickbook. Review Result: Based on the voting for acceptance or not, based on the discussions during the review period, and based on Steven Ross's responses, I have decided that Steven Ross's library should be accepted into Boost. My main reason for my decision, aside from the votes and comments and specific issues discussed, is twofold: 1) There is a general consensus that Steven Ross has an excellent understanding of sorting techniques and algorithms and will support and refine his library for the benefit of programmers. 2) The empirical tests show that SpreadSort offers an improvement over std::sort, significantly in the area of large data sets, and this could be a major benefit to programmers. I do not know if the review manager has a say in this but based on the remarks of the reviewers I would like to see the library as accepted be named 'SpreadSort' rather than just 'Sort'. I do think that Boost can have a library called 'Sort' but I agree with the general consensus that a 'Sort' library needs more than one type of sorting algorithm. I would like to see other people, who mentioned in the reviews/comments that they have their own sorting implementation, also submit their own implementations to Boost and, if this happens and they are accepted, I can see combining them with 'SpreadSort' into a general Boost sorting library called 'Sort' in the future.

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[VC++ 14.0 preview] New failures in develop regression tests
by Beman Dawes 03 Dec '14

03 Dec '14

At my request, Tom Kent has kindly added VC++ 14.0 (toolset msvc-14.0) to his develop branch tests. See http://www.boost.org/development/tests/develop/developer/summary.html rightmost column. This compiler is available as part of the Visual Studio 2015 Preview. See http://www.visualstudio.com/en-us/downloads/visual-studio-2015-downloads-vs… Several libraries are showing new test failures. Please check out the test results to see if your library has started to fail. If it is your problem, fix it or at least create a ticket for yourself:-) If it is a Microsoft problem, consider submitting a bug report and posting a notice on the Boost list so that other developers are aware of the problem. Also post a link to the bug report on https://connect.microsoft.com Knowing the Microsoft Connect URL for the bug report lets other boosters up vote the importance of the issue. This is known to have at least some influence on the priority given the bug report, and that means faster fixes for the bugs boosters care about. Thanks, --Beman

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GDB-like debugger for template metaprograms
by Abel Sinkovics 03 Dec '14

03 Dec '14

Hi, Metashell 2.0.0 has a template metaprogram debugger with a GDB-like interface (thanks to András Kucsma), which can be useful for Boost developers. It can show you how your metaprogram is executed step-by-step. You can set breakpoints, step into or over the metafunction calls and inspect the "template metaprogramming stack trace" at any point during this: the chain of recursive template instantiations that lead to that point. Here is an example: > #include <boost/mpl/transform.hpp> > #include <boost/mpl/vector_c.hpp> > #include <boost/mpl/plus.hpp> > #include <boost/mpl/lambda.hpp> > #include <boost/mpl/int.hpp> > using namespace boost::mpl; > #msh mdb transform<vector_c<int, 1, 2, 3, 4, 5>, plus<_1, int_<1>>>::type For help, type "help". Metaprogram started (mdb) rbreak ^boost::mpl::plus Breakpoint "^boost::mpl::plus" will stop the execution on 25 locations (mdb) continue Breakpoint "^boost::mpl::plus" reached boost::mpl::plus<mpl_::integral_c<int, 1>, mpl_::int_<1>, mpl_::na, mpl_::na, mpl_::na> (Memoization) (mdb) bt #0 boost::mpl::plus<mpl_::integral_c<int, 1>, mpl_::int_<1>, mpl_::na, mpl_::na, mpl_::na> (Memoization) #1 boost::mpl::quote_impl<boost::mpl::plus<mpl_::integral_c<int, 1>, mpl_::int_<1>, mpl_::na, mpl_::na, mpl_::na>, true> (TemplateInstantiation) #2 boost::mpl::quote5<plus, mpl_::void_>::apply<mpl_::integral_c<int, 1>, mpl_::int_<1>, mpl_::na, mpl_::na, mpl_::na> (TemplateInstantiation) #3 boost::mpl::apply_wrap5<boost::mpl::quote5<plus, mpl_::void_>, mpl_::integral_c<int, 1>, mpl_::int_<1>, mpl_::na, mpl_::na, mpl_::na> (TemplateInstantiation) ... #19 transform<vector_c<int, 1, 2, 3, 4, 5>, plus<_1, int_<1>>>::type You can try Metashell from your browser: http://abel.web.elte.hu/shell Or you can install it on your computer: https://github.com/sabel83/metashell#version-200 Binary installers are available for a number of Linux distributions, Windows and Mac OS X. Feedback is welcome. Regards, Ábel

7 15

boost::async documentation
by Aaron Levy 29 Nov '14

29 Nov '14

I did not see any explicit documentation of the boost::async template although I see some mention of it since Boost 1.53. Is there some cohesive documentation which lists: 1. The macros needed to enable the functionality if any. 2. Details of behavior and limitations. 3. Differences in behavior wrt std::async. -- Aaron Levy aaron.levy(a)yandex.com

2 1

boost.context cause strange crash on certan WIN32 API
by microcai 29 Nov '14

29 Nov '14

Hi, I was using Boost.Asio.Spawn happliy until I ported my project to windows. I got stange openssl crash. many debug days speeded and there was nothing wrong with openssl. Strange thing is, openssl didn't crash when used in normal code, unless I used them in asio stackful coroutine. Now I finnally find the root cause and make it 100% reproducible. here is the code that demostrade the crash: <code> boost::context::fcontext_t fcm,fc1; void f1(intptr_t) { HMODULE advapi = LoadLibrary(TEXT("advapi32")); // crash there FreeLibrary(advapi); boost::context::jump_fcontext(fc1, &fcm, 0); } std::thread([](){ boost::context::guarded_stack_allocator alloc; std::size_t size(8192); void* sp1(std::malloc(size)); fc1=boost::context::make_fcontext(sp1, size, f1); boost::context::jump_fcontext(&fcm, fc1, 0); }); </code> the context created in threads other that main thread, can't call certain APIs. If LoadLibrary get called by an context that created in thread, it will crash. 100% reproducible on WIN64 platform with MSVC2013. And nothing wrong on WIN32 !

2 2

[Boost.Convert] Specify input using iterators
by Marius Dobrea 28 Nov '14

28 Nov '14

Hi Vladimir, While reading the Boost.Convert documentation last night there were some questions which came to my mind: Have you considered using iterators (or ranges) to specify input? Would that be in the scope of your library? Also I note that the strtol() function returns the position of the first invalid character (endptr below): long int strtol (const char* str, char** endptr, int base); Could convert() provide the position where the conversion stopped? This would allow single pass parsing of some input data. Would a Converter callable with the following signature be useful? template<typename TypeOut, typename InputIterator> class Result { public: enum Errc { numeric_overflow, empty_range, invalid_character, ...}; // std::expected like function signatures here private: TypeOut value; int errors; InputIterator pos; }; template<typename TypeOut, typename InputIterator> void operator()(InputIterator begin, InputIterator end, Result<TypeOut, InputIterator>& result) const; Please let me know your thoughts. Thanks, Marius Dobrea

2 1

[optional] Safe optional
by Andrzej Krzemienski 28 Nov '14

28 Nov '14

Hi Everyone, I would like to run an idea through everyone in this list. There is a recurring complaint about Boost.Optional that it allows you to do "unsafe" things: 1. Inadvertent mixed comparisons between T and optional<T> 2. Unintended conversion from T to optional<T> 3. "Unchecked" access to the contained object, which causes an UB when performed on an uninitialized optional object. There are valid reasons why optional is defined the way it is defined. But at the same time the complaints above are also valid. This makes some people abandon Boost.Optional and use their own alternative. My idea is to provide another type wrapper, say safe_optional<T>, that would choose different tradeoffs: prefer "safety" to some flexibility and/or efficiency. It would probably be part of Boost.Optional library as the implementation can be reused - only the interface would be changed. One downside of this solution is that we would have two libraries for doing nearly the same thing, which could "scatter" the community. There is a value for standardizing certain things and making them universal. I would like to solicit your feedback. Regards, &rzej

18 84

Explicit conversions to a contextual target type (was [optional] operator<(optional<T>, T) -- is it wrong?)
by Vicente J. Botet Escriba 27 Nov '14

27 Nov '14

Le 26/11/14 12:00, Vladimir Batov a écrit : I have started a new thread to try to clarify what I have in my mind. >> ... I'm looking on how all these conversions can be made safer. >> ... > OK, Vicente, my most humble apologies for snipping all the stuff you typed > that flew right over my head and made me feel stupid. I have to be brutally > honest I did not understand your "idea to state explicitly that you want a > explicit conversion but don't state to what" and your "implicit explicit > conversion thing". You obviously put a lot of thought into it but I > personally did not get *what problem* exactly you are trying to solve. I > personally do not feel there is a conversion-related problem that needs > fixing... On the other hand I do not know Haskell, so it may well be that I > do not know what I am missing. :-) I just hope that other people you'll > present your idea to will be smarter than me to appreciate it. Do you have > any links to slow-pace tutorial/explanation/justification of what you are > trying to propose that I could peruse without hurry? > > I will try again, but I'm not sure I will be clearer this time :( NOTE: this has nothing to be with a library solution, not with the current C++ language, and so it could be out of the scope of this ML. Please, skip this post if you are not concerned by how other language can influence C++. Just 3 references to Haskell * http://adit.io/posts/2013-04-17-functors,_applicatives,_and_monads_in_pictu… * http://en.wikibooks.org/wiki/Haskell/Understanding_monads * https://www.haskell.org/haskellwiki/Polymorphism C++ doesn't takes in account the result type of a function during overload resolution. This has its advantages and liabilities. Consider the following situation. Given void f(W<T>); template <template<class> class B, class A> B<A> make(A v) { return B<A>(v); } It seems reasonable to define a function void g(X x) { f(make<W>(x)); } Here we are conveying the context via the template class W, that is, we are explicit about the context. Consider now a system on which the overload resolution takes in account the target type. Let me use [] instead of () to wrap the function parameters and arguments for this kind of functions so that we can identify them in an easy way. First of all we need to identify the context on which the function has a sens. Let me call this construction just *context*. template <template <class> class B> * context* Builder { template <class T> B<T> make [ T v ]; }; The function 'make' has only one argument, but its result type depends on the context. void g(X x) { f( make[x] ); } The result of make[x] has no sens if we don't know what the target type is. In the expression f( make [x] ) the target of the expression make [x] is W<X> and the context would be W. So the overload that will be taken would be Builder<W>::make[X]. We need to say what Builder<W>::make[X] means, if it would even has a meaning. In order to give a meaning to this expression we need to map W as a builder * template <> context* Builder<W> { template <class T> W<T> make [ T v ] { return whatever_you_want_that_returns_w_t(c); } }; Note that in Haskell the keywords are class for context, and instance for context_map. In some way, we could say that Builder is a type-class having types as instances, and a type belong to this type-class if there is an explicit mapping. This has a lot to be with the abandoned Concept-0x proposal, which was based on signature mapping. The current C++ Concept Lite trend is to have a default mapping for those types that satisfy a set of some syntactical constraint. I think that we could build something similar to Concept-0x on top of Concept Lite, but of course without the help of the language it would be more verbose as we will need to add an indirection. There are also some similarities with the object oriented approach, but instead of having an explicit object you have an deduced context that determines the function to call using static polymorphism. This kind of polymorphism is called ad-hoc polymorphism in the literature an in particular it is used in Haskell and Rust. Another example, this time with a variable * context* ProbablyValued PV { // constructors PV make [ ValueType<PV> v ]; constexpr PV none; // accessors ... }; Ad-hoc polymorphism has its own liabilities also of course. Best, Vicente P.S. I'm not serious. Having another way to do polymorphic calls in c++ is not reasonable, or is it?

1 0

[review] Sort library review manager results
by Edward Diener 26 Nov '14

26 Nov '14

This is the results from the recent review of the Sort library of Steven Ross. First I would like to thank all those who made comments during the review, whether or not they officially gave a final Yes or No vote to whether the Sort library should be accepted as a Boost library. This list includes: Niall Douglas, Julian Gonggrijp, Phil Endecott, Vladimir Prus, Mathias Gaunard, Jeremy Murphy, Peter Dimov, Robert Ramey, Adam Walling, Anthony Polukhin, Phil Endecott, Paul Bristow, Thijs (M.A.) van den Berg Dupuis Etienne, and Frank Gennari If I have missed anyone I do apologize. Secondly I would like to thank Steven Ross for patiently answering all of the review comments to the best of his ability. My tally of Yes and No votes for acceptance are: Yes votes (5) : Niall Douglas ( conditional ), Julian Gonggrijp ( conditional ), Frank Gennari, Phil Endecott, Paul Bristow. No votes (3) : Vladimir Prus, Adam Walling ( conditional ), Anthony Polukhin I believe the condtional Yes vote from Julian Gonggrijp was completely met in the discussions of issues with Steven Ross and the conditional Yes vote from Niall Douglass was almost completely met in the discussion with Steven Ross about the issues mentioned. I want to also mention that the conditional No vote by Adam Walling has an implied Yes vote to it if the Sort library were one among other sort implementations. Since my final decision is not entirely based on the Yes and No votes I want to adumbrate some of the major issues brought up by the review without necessarily focussing on every one of the people who brought them up initially, as well as my own reactions to them as Review Manager. 1) The first major issue was whether a library whose basic merit lies in its algorithm and its speed/space constraints needs better theoretical backing. A number of reviewers discussed this after it was brought up. I tend to agree with reviewers that while the best theoretical basis is always desirable, it is not necessary for a Boost library whose empirical evidence can be and has been measured by its implementor and can be measured by any user. Furthermore Steven Ross has provided an extensive discussion in his documentation, as well as his original paper, about the theoretical merits of his technique. While much of this discussion is probably beyond the understanding of any but sorting experts and afficionados ( I am neither ) enough of it adequately explains the basic ideas behind SpreadSort for those who understand and have knowledge of basic sorting ideas and popular sorting techniques ( that's my province ). 2) An important issue is the need for the Sorting library to provide extensive timing charts/tables comparing SpreadSort to at least std::sort ( and possibly other popular mainstream sorts ) with both different numbers of sort keys and different initial unsorted distributions.

1 1

Re: [boost] [optional] operator<(optional<T>, T) -- is it wrong?
by Felix Uhl 26 Nov '14

26 Nov '14

Vincente J. Botet Escriba wrote: >I hope it is clear now that I don't want to change optional but see what >the safer optional could be with the ongoing C++ proposals. Fair enough, different users want different behaviour, but how is optional not safe in any way? operator<(optional<T>, T) does not throwing any kinds of exceptions when operator<(T,T) doesn’t, does it? --- Felix Uhl

2 1

[boost config] BOOST_NO_CXX11_HDR_CODECVT question
by Robert Ramey 26 Nov '14

26 Nov '14

I'm building on Mac OS with Xcode. The following test program seems to demonstrate a problem either with config or my understanding of it. <code> #include <codecvt> #include <boost/config.hpp> #ifdef BOOST_NO_CXX11_HDR_CODECVT #pragma message "no C++ codevt support" #endif #include "../../../libs/config/test/config_info.cpp" </code> When I compile the following I get a compile time message "no C++ codevt support" which is NOT what I expect to see. This surprises me since if the message is correct, I would expect the compile would fail at that #include <codecvt> statement. When I run the program I get: Clang version 6.0 (clang-600.0.54) __cplusplus =199711L __STDC__ =1 __GNUC__ =4 __GNUC_MINOR__ =2 __GNUC_PATCHLEVEL__ =1 __GNUG__ =4 __VERSION__ ="4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.54)" __REGISTER_PREFIX__ [no value] __USER_LABEL_PREFIX__ =_ __EXCEPTIONS =1 __GXX_RTTI =1 __LP64__ =1 __MACH__ =1 __APPLE__ =1 __APPLE_CC__ =6000 __STDC_HOSTED__ =1 ********************************************************************* libc++ version 1101 _LIBCPP_VERSION =1101 ********************************************************************* Detected Platform: Mac OS Type char is signed Type wchar_t is signed byte order for type short =0 8 byte order for type int =0 8 16 24 byte order for type long =0 8 16 24 32 40 48 56 sizeof(wchar_t) =4 sizeof(short) =2 sizeof(int) =4 sizeof(long) =8 sizeof(size_t) =8 sizeof(ptrdiff_t) =8 sizeof(void*) =8 sizeof(void(*)(void)) =8 sizeof(float) =4 sizeof(double) =8 sizeof(long double) =16 CHAR_BIT =8 CHAR_MAX =127 WCHAR_MAX =2147483647 SHRT_MAX =32767 INT_MAX =2147483647 LONG_MAX =9223372036854775807L LLONG_MAX =0x7fffffffffffffffLL LONG_LONG_MAX =9223372036854775807LL ULLONG_MAX =0xffffffffffffffffULL ULONG_LONG_MAX =(9223372036854775807LL*2ULL+1ULL) _POSIX_ADVISORY_INFO =(-1) _POSIX_ASYNCHRONOUS_IO =(-1) _POSIX_BARRIERS =(-1) _POSIX_CHOWN_RESTRICTED =200112L _POSIX_CLOCK_SELECTION =(-1) _POSIX_CPUTIME =(-1) _POSIX_FSYNC =200112L _POSIX_JOB_CONTROL =200112L _POSIX_MAPPED_FILES =200112L _POSIX_MEMLOCK =(-1) _POSIX_MEMLOCK_RANGE =(-1) _POSIX_MEMORY_PROTECTION =200112L _POSIX_MESSAGE_PASSING =(-1) _POSIX_MONOTONIC_CLOCK =(-1) _POSIX_NO_TRUNC =200112L _POSIX_PRIORITIZED_IO =(-1) _POSIX_PRIORITY_SCHEDULING =(-1) _POSIX_RAW_SOCKETS =(-1) _POSIX_READER_WRITER_LOCKS =200112L _POSIX_REALTIME_SIGNALS =(-1) _POSIX_REGEXP =200112L _POSIX_SAVED_IDS =200112L _POSIX_SEMAPHORES =(-1) _POSIX_SHARED_MEMORY_OBJECTS =(-1) _POSIX_SHELL =200112L _POSIX_SPAWN =(-1) _POSIX_SPIN_LOCKS =(-1) _POSIX_SPORADIC_SERVER =(-1) _POSIX_SYNCHRONIZED_IO =(-1) _POSIX_THREAD_ATTR_STACKADDR =200112L _POSIX_THREAD_ATTR_STACKSIZE =200112L _POSIX_THREAD_CPUTIME =(-1) _POSIX_THREAD_PRIO_INHERIT =(-1) _POSIX_THREAD_PRIO_PROTECT =(-1) _POSIX_THREAD_PRIORITY_SCHEDULING =(-1) _POSIX_THREAD_PROCESS_SHARED =200112L _POSIX_THREAD_SAFE_FUNCTIONS =200112L _POSIX_THREAD_SPORADIC_SERVER =(-1) _POSIX_THREADS =200112L _POSIX_TIMEOUTS =(-1) _POSIX_TIMERS =(-1) _POSIX_TRACE =(-1) _POSIX_TRACE_EVENT_FILTER =(-1) _POSIX_TRACE_INHERIT =(-1) _POSIX_TRACE_LOG =(-1) _POSIX_TYPED_MEMORY_OBJECTS =(-1) _POSIX_VDISABLE =((unsigned char)'\377') _POSIX_VERSION =200112L _POSIX2_C_BIND =200112L _POSIX2_C_DEV =200112L _POSIX2_CHAR_TERM =200112L _POSIX2_FORT_DEV =(-1) _POSIX2_FORT_RUN =200112L _POSIX2_LOCALEDEF =200112L _POSIX2_PBS =(-1) _POSIX2_PBS_ACCOUNTING =(-1) _POSIX2_PBS_CHECKPOINT =(-1) _POSIX2_PBS_LOCATE =(-1) _POSIX2_PBS_MESSAGE =(-1) _POSIX2_PBS_TRACK =(-1) _POSIX2_SW_DEV =200112L _POSIX2_UPE =200112L _POSIX2_VERSION =200112L _V6_ILP32_OFF32 =(-1) _V6_ILP32_OFFBIG =(1) _V6_LP64_OFF64 =(1) _V6_LPBIG_OFFBIG =(1) _XBS5_ILP32_OFF32 =(-1) _XBS5_ILP32_OFFBIG =(1) _XBS5_LP64_OFF64 =(1) _XBS5_LPBIG_OFFBIG =(1) _XOPEN_CRYPT =(1) _XOPEN_ENH_I18N =(1) _XOPEN_LEGACY =(-1) _XOPEN_REALTIME =(-1) _XOPEN_REALTIME_THREADS =(-1) _XOPEN_SHM =(1) _XOPEN_STREAMS =(-1) _XOPEN_UNIX =(1) _XOPEN_VERSION =600 ********************************************************************* Boost version 105700 BOOST_USER_CONFIG =<boost/config/user.hpp> BOOST_COMPILER_CONFIG ="boost/config/compiler/clang.hpp" BOOST_STDLIB_CONFIG ="boost/config/stdlib/libcpp.hpp" BOOST_PLATFORM_CONFIG ="boost/config/platform/macos.hpp" BOOST_HAS_THREADS [no value] BOOST_DEDUCED_TYPENAME =typename BOOST_HAS_DIRENT_H [no value] BOOST_HAS_EXPM1 [no value] BOOST_HAS_GETTIMEOFDAY [no value] BOOST_HAS_INT128 [no value] BOOST_HAS_LOG1P [no value] BOOST_HAS_LONG_LONG [no value] BOOST_HAS_NANOSLEEP [no value] BOOST_HAS_NL_TYPES_H [no value] BOOST_HAS_NRVO [no value] BOOST_HAS_PARTIAL_STD_ALLOCATOR [no value] BOOST_HAS_PTHREADS [no value] BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE [no value] BOOST_HAS_SCHED_YIELD [no value] BOOST_HAS_SIGACTION [no value] BOOST_HAS_STDINT_H [no value] BOOST_HAS_UNISTD_H [no value] BOOST_MSVC6_MEMBER_TEMPLATES [no value] BOOST_NO_CXX11_ADDRESSOF [no value] BOOST_NO_CXX11_ALIGNAS [no value] BOOST_NO_CXX11_ALLOCATOR [no value] BOOST_NO_CXX11_ATOMIC_SMART_PTR [no value] BOOST_NO_CXX11_AUTO_DECLARATIONS [no value] BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS [no value] BOOST_NO_CXX11_CHAR16_T [no value] BOOST_NO_CXX11_CHAR32_T [no value] BOOST_NO_CXX11_CONSTEXPR [no value] BOOST_NO_CXX11_DECLTYPE [no value] BOOST_NO_CXX11_DECLTYPE_N3276 [no value] BOOST_NO_CXX11_DEFAULTED_FUNCTIONS [no value] BOOST_NO_CXX11_DELETED_FUNCTIONS [no value] BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS [no value] BOOST_NO_CXX11_FINAL [no value] BOOST_NO_CXX11_FIXED_LENGTH_VARIADIC_TEMPLATE_EXPANSION_PACKS [no value] BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS [no value] BOOST_NO_CXX11_HDR_ARRAY [no value] BOOST_NO_CXX11_HDR_ATOMIC [no value] BOOST_NO_CXX11_HDR_CHRONO [no value] BOOST_NO_CXX11_HDR_CODECVT [no value] BOOST_NO_CXX11_HDR_CONDITION_VARIABLE [no value] BOOST_NO_CXX11_HDR_FORWARD_LIST [no value] BOOST_NO_CXX11_HDR_FUNCTIONAL [no value] BOOST_NO_CXX11_HDR_FUTURE [no value] BOOST_NO_CXX11_HDR_INITIALIZER_LIST [no value] BOOST_NO_CXX11_HDR_MUTEX [no value] BOOST_NO_CXX11_HDR_RANDOM [no value] BOOST_NO_CXX11_HDR_RATIO [no value] BOOST_NO_CXX11_HDR_REGEX [no value] BOOST_NO_CXX11_HDR_SYSTEM_ERROR [no value] BOOST_NO_CXX11_HDR_THREAD [no value] BOOST_NO_CXX11_HDR_TUPLE [no value] BOOST_NO_CXX11_HDR_TYPEINDEX [no value] BOOST_NO_CXX11_HDR_TYPE_TRAITS [no value] BOOST_NO_CXX11_HDR_UNORDERED_MAP [no value] BOOST_NO_CXX11_HDR_UNORDERED_SET [no value] BOOST_NO_CXX11_INLINE_NAMESPACES [no value] BOOST_NO_CXX11_LAMBDAS [no value] BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS [no value] BOOST_NO_CXX11_NOEXCEPT [no value] BOOST_NO_CXX11_NON_PUBLIC_DEFAULTED_FUNCTIONS [no value] BOOST_NO_CXX11_NULLPTR [no value] BOOST_NO_CXX11_NUMERIC_LIMITS [no value] BOOST_NO_CXX11_RANGE_BASED_FOR [no value] BOOST_NO_CXX11_RAW_LITERALS [no value] BOOST_NO_CXX11_REF_QUALIFIERS [no value] BOOST_NO_CXX11_RVALUE_REFERENCES [no value] BOOST_NO_CXX11_SCOPED_ENUMS [no value] BOOST_NO_CXX11_SMART_PTR [no value] BOOST_NO_CXX11_STATIC_ASSERT [no value] BOOST_NO_CXX11_STD_ALIGN [no value] BOOST_NO_CXX11_TEMPLATE_ALIASES [no value] BOOST_NO_CXX11_TRAILING_RESULT_TYPES [no value] BOOST_NO_CXX11_UNICODE_LITERALS [no value] BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX [no value] BOOST_NO_CXX11_USER_DEFINED_LITERALS [no value] BOOST_NO_CXX11_VARIADIC_TEMPLATES [no value] BOOST_NO_MS_INT64_NUMERIC_LIMITS [no value] BOOST_NO_STD_MESSAGES [no value] BOOST_STD_EXTENSION_NAMESPACE =std BOOST_UNREACHABLE_RETURN(0) [no value] BOOST_CONSTEXPR [no value] BOOST_CONSTEXPR_OR_CONST =const BOOST_STATIC_CONSTEXPR =static const BOOST_NOEXCEPT [no value] BOOST_FORCEINLINE =inline __attribute__ ((__always_inline__)) BOOST_NOINLINE =__attribute__ ((__noinline__)) BOOST_FALLTHROUGH =((void)0) Program ended with exit code: 0 which also surprises me as I was under the impression that my compiler implements all of C++11 library standard Any help appreciated, Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/boost-config-BOOST-NO-CXX11-HDR-CODECVT-… Sent from the Boost - Dev mailing list archive at Nabble.com.

1 1

Template Help
by john.klein＠genovatech.com 26 Nov '14

26 Nov '14

All, I've gotten rusty over the years and decided to create an application for myself to knock some of the rust off. I've worked with projects that have used boost in the past and I'm wanting to use it as much as possible here. I'm using VS2013 with the 64bit 1.57.0 boost libraries, so I have access to the newer c++ standard. Can someone please show me how to get the following to compile? Please ignore the functionality of the code, this is just something I quickly put together to demo my issue. SafeList.h #pragma once #include <list> #include <boost/thread/mutex.hpp> template <typename dataType> using CallbackType = bool(*)(dataType); template <typename dataType> class SafeList { public: SafeList() : list(), mutex() { } ~SafeList() { boost::mutex::scoped_lock scoped_lock(mutex); } void Add(dataType data) { boost::mutex::scoped_lock scoped_lock(mutex); list.push_back(data); } void Remove(dataType data) { boost::mutex::scoped_lock scoped_lock(mutex); list.remove(data); } void IterateList(CallbackType<dataType> callback) { boost::mutex::scoped_lock scoped_lock(mutex); for (int i = 0, bool flag = true; i < list.size() && flag; i++) { flag = callback(list[0]); } } private: std::list<dataType> list; boost::mutex mutex; }; FileList.h #pragma once #include "SafeList.h" #include "File.h" #include <boost/shared_ptr.hpp> typedef boost::shared_ptr<File> FilePtr; class FileList { public: FileList(); ~FileList(); void Add(FilePtr); void ProcessList(); private: bool ProcessItem(FilePtr); SafeList<FilePtr> safeList; }; FileList.c #include "stdafx.h" #include "FileList.h" FileList::FileList() : safeList() { } FileList::~FileList() { } void FileList::Add(FilePtr filePtr) { safeList.Add(filePtr); } void FileList::ProcessList() { safeList.IterateList(this->ProcessItem); <-- This is the bad guy the compiler complains about and not sure how to resolve. } bool FileList::ProcessItem(FilePtr) { return true; } 1>------ Build started: Project: Download, Configuration: Debug x64 ------ 1> FileList.cpp 1>FileList.cpp(20): error C3867: 'FileList::ProcessItem': function call missing argument list; use '&FileList::ProcessItem' to create a pointer to member ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Thanks, John Klein PMP(r) CSM(r) Programs/Engineer Manager Phone: (319) 378-8455 Cell: (319) 533-1476 [Description: Genova Tech NEW] www.genovatech.com<http://www.genovatech.com/> 4250 River Center Court NE Suite A Cedar Rapids, IA 52402 This message is covered by the Electronic Communication Privacy Act, 18 U.S.C. Sections 2510-2515, and is intended only for the use of the person to whom it is addressed and may contain information that is confidential. It should not be forwarded to anyone else. If you received this message and are not the addressee, you have received this message in error. Please notify the person sending the message and destroy your copy.

3 2

[optional] operator<(optional<T>, T) -- is it wrong?
by Andrzej Krzemienski 26 Nov '14

26 Nov '14

I moved this discussion from the other thread. > optional<double> Aircraft::weight() > { > if (Impl* impl = get_impl()) > return impl->compute_weight(); > else > return none; > } > > double Aircraft::max_weight() > { > return 10000.0; > } > > bool too_heavy(Aircraft& ac) > { > return ac.weight() > ac.max_weight(); > // this compiles and does the wrong thing > } > 1) When we are bringing T into the optional<T> land, we apply implicit > constructor. For example, we provide T to a function taking optional<T>. > Here, the direction of the conversion is unambiguous. Namely, T to > optional<T>. So, we apply it. > 2) When the direction of conversion is not as clear, we refuse applying it > and leave it to the user. op<(T, optional<T>) would be one such example. > > Oh, c'mon. Cheer up. Things are not as gloomy, are they. :-) Here the > subtlety (IMO) lies in how reasonable it is to add information. Namely, as > I indicated, if we bring T into the optional<T> fold, then we apply > optional<T> rules to T, i.e. apply t to optional<T> conversion. Say, we > have a mandarin and an orange. When we bring the mandarin to an orange > factory, then mandarin-to-orange "conversion" is applied and for all > purposes mandarin is a "small orange". Outside the factory, when we compare > mandarin to orange, it is not immediately clear what should be treated as > what. If we apply mandarin-to-orange "conversion", then it'll be "small > orange vs. big orange". If instead we apply orange-to-mandarin > "conversion", then it'll be "sweet mandarin vs. sour mandarin". Given the > library writer does not know, which it is, we ban it. Still not convinced? > I've spent all munition I had. :-) When you are talking about oranges and mandarins outside the context of C++, I am convinced. the problem I have is with mapping it onto C++ and the design of Optional. (1) In C++ we have the converting constructor. This appears close to what you call "bringing T into the optional<T> land", but I claim it is not the same. And the consequences of these nuance differences result in the problem in question. Perhaps the notion of "bringing T into the optional<T> land" would be better reflected by an explicit constructor, or function make_optional(). I am not saying that the converting constructor is wrong here. I am just saying that the motivation is *slightly* different than "bringing T into the optional<T> land", it is more for syntactic convenience, which is almost the same, but not same. (2) Your philosophy "when the direction of conversion is not as clear, we refuse applying it" -- there is no way to apply it within the definition of optional. We can apply it by poisoning every operation in the world that takes T or optional<T>. But that looks impractical. Back to Vicente's concern: User defining its own function > > void f(optional<T>, optional<T>); > > would need to add the following? > > void f(T, optional<T>) { BOOST_STATIC_ASSERT(); } > void f(optional<T>, T) { BOOST_STATIC_ASSERT(); } > > What if there are 3 optional parameters? We can not say to the user that > they need to program this way. > I do not think it has been addressed.

9 20

[Range] New I/O functions for ranges
by Indiana 25 Nov '14

25 Nov '14

I'm currently putting together a proposal to the standards committee about a set of range I/O functions, but i think they would make a good addition to Boost as well. They would probably fit in the Range library - i don't think they warrant a library all of their own. The stuff i wrote for the standards proposal is available at http://cpp.indi.frih.net/rangeio/ - it goes into quite a bit of detail about the interface, and links to a sample implementation. But here's the executive summary: There is a single output function - currently called "write_all" - that takes a range and, optionally, a delimiter, like this: // BEGIN CODE ///////////////////////// auto const r = std::array<int, 4>{1, 2, 3, 4}; cout << write_all(r); // prints "1234" cout << "{ " << write_all(r, ", ") << " }"; // prints "{ 1, 2, 3, 4 }" // END CODE /////////////////////////// It takes anything that works with range-for, so it works with range adaptors: // BEGIN CODE ///////////////////////// struct is_even { auto operator()(int x) const -> bool { return x % 2 == 0; } }; cout << write_all(r | reversed | filtered(is_even{})); // prints "42" // END CODE /////////////////////////// Note also that the delimiter doesn't have to be a string (there are some examples in the reference of that). Why not just use std::copy() and stream iterators? Several reasons - the most obvious of which you can see above: this syntax is much cleaner, much less error-prone, well-integrated with the existing stream I/O mechanisms, and it produces properly delimited output (unlike the delimited version of ostream_iterator). But also, stream formatting is properly handled: // BEGIN CODE ///////////////////////// auto const r = std::array<int, 3>{1, 2, 3}; std::cout.width(3); std::cout.fill('0'); // --------------------------- // The old way: using std::begin; using std::end; std::copy(begin(r), end(r), std::ostream_iterator<int>{std::cout, ", "}); // even with Boost.Range, this just reduces to: //boost::copy(r, std::ostream_iterator<int>{std::cout, ", "}); // prints: "001, 2, 3, " // --------------------------- // The new way: std::cout << write_all(r, ", "); // prints "001, 002, 003" // END CODE /////////////////////////// And of course this works as expected in chained expressions: // BEGIN CODE ///////////////////////// auto const r = array<int, 3>{1, 2, 3}; cout.width(3); cout.fill('0'); cout << '(' << setw(3) << setfill('0') << write_all(r, ',') << ')'; // prints: "(001,002,003)" // END CODE /////////////////////////// It is also possible to get more information about errors, and react better to them. If there is an error in the formatting or in the stream during an output operation using std::copy() and ostream_iterator, the algorithm will chug merrily along until it's all the way through the range even though it's no longer writing anything. You will have no way to detect where the problem occurred - did it fail after the first element was written, or *before*, or did it fail after the millionth element? If the range is begin lazy-generated, that could be particularly wasteful, or even problematic. By contrast, write_all() stops immediately when there is an error in the output stream. It is even possible get more information about the last range write operation by capturing the temporary object, like this: // BEGIN CODE ///////////////////////// auto const r = array<int, 3>{1, 2, 3}; auto p = write_all(r); cout << p; if (!cout) { cerr << "only " << p.count << " elements written\n"; cerr << "next element would have been " << *p.next << '\n'; } // END CODE /////////////////////////// On the input side, there are 7 functions: * overwrite * back_insert * front_insert * insert * back_insert_n * front_insert_n * insert_n Overwrite simply replaces the contents of a range with whatever is read from input: // BEGIN CODE ///////////////////////// auto r = array<int, 100>{}; cin >> overwrite(r); // reads up to 100 ints // END CODE /////////////////////////// The *insert functions map to the *insert_iterators in the standard library, using push_back(), push_front(), or insert(). In each case: in >> ???insert(r[, i]); is basically equivalent to: copy(istream_iterator<value_type_of_r>{in}, // use braces on the next line, or face the most vexing parse istream_iterator<value_type_of_r>{}, ???inserter(r[, i])); The *insert_n functions are for the common case where you know in advance how many elements will be read, at maximum - or for when you want to limit the amount of elements read in a single read operation. This: in >> ???insert_n(r[, i], n); is conceptually equivalent to: copy_n(istream_iterator<value_type_of_r>{in}, n, ???inserter(r[, i])); except it can handle formatting and errors properly. The reference at http://cpp.indi.frih.net/rangeio/ goes into much more detail, of course. Why add it to Boost? Because these operations (reading/writing ranges) are so common they are almost universal, and there is no standard facility that handles them easily or well. They are not *difficult* to implement, but they are far from trivial - for example, you might think write_all() is just a simple range-for loop or for_each(), and it is... up until you add error checking, the delimiter, and formatting awareness. A sample implementation already exists - it can be implemented portably in pure standard C++11. (Can it be implemented in C++03 with? Good question. It might be possible with some Boost help, but it might require dependencies on libraries other than Boost.Range. If this proposal finds approval, that's something i can look into.) Would there be any interest in adding these functions to Boost.Range?

5 13

[range][extensions] What is happening with the range extensions?
by Viktor Sehr 25 Nov '14

25 Nov '14

I really think boost range should be updated with the range extensions, what is happening with the review here? /Viktor

3 2

[range][extensions] Operator |+, isnt it possible to implement without this operator?
by Viktor Sehr 25 Nov '14

25 Nov '14

Looking at CppLinq, and C++ Streams (http://jscheiny.github.io/Streams/) it seems they both can handle lambda functions via one operator. Isn't it possible to do something like they do in range extensions? /Viktor

2 1

[Serialization] boost/strong_typedef.hpp vs. boost/serialization/strong_typedef.hpp
by Jonathan Jones 24 Nov '14

24 Nov '14

Hi folks, Does anyone know why boost/strong_typedef.hpp still exists with real content? Several years back, the version in the trunk was stubbed out: http://svn.boost.org/svn/boost/trunk/boost/strong_typedef.hpp but this change has not made it into any release. The version in serialization, however, is still being updated. Sincerely, Jonathan Jones

2 3

[dynamic_bitset] capacity(), reserve(), shrink_to_fit()
by Riccardo Marcangelo 24 Nov '14

24 Nov '14

Hi, I have implemented capacity(), reserve(), and shrink_to_fit() for dynamic_bitset. I find these useful and am surprised by their omission. I'm wondering if there is any interest in including them in Boost. Perhaps there are reasons why they're not implemented? Riccardo -- View this message in context: http://boost.2283326.n4.nabble.com/dynamic-bitset-capacity-reserve-shrink-t… Sent from the Boost - Dev mailing list archive at Nabble.com.

2 3

Executable files in the boost tree
by Marshall Clow 24 Nov '14

24 Nov '14

Someone recently opened trac ticket #10813 (https://svn.boost.org/trac/boost/ticket/10813) with the description: > I recently updated Boost 1.57, I noticed that a few header files > "parameter.hpp" and some of those in the "parameter" directory has > permission 755 instead of normal 644. Why make these normal header files > executable? Since I built the release tarballs, I took this ticket and did some investigating. The OP is absolutely correct, these files should not have 755 perms. Unfortunately for me, I discovered: 1) These permissions were not modified during the build process, but are marked this way in git. 2) It’s not just the parameter library. I found about 1000 files marked as executable that shouldn’t be, and they were in the following libraries: asio assign bimap chrono concept_check foreach fusion gil graph iostreams lambda mpl msm numeric parameter polygon predef ptr_container python test thread type_traits typeof variant xpressive Some files (such as shell scripts, python sources, etc) *should* be marked executable, but others (.hpp files, jam files, HTML, png, etc) should not. I will deal with the libraries that are currently under the purview of the CMT (concept_check and mpl) I would appreciate if the maintainers of these libraries would clean this up before the Feb release. Also, I will be enhancing the “inspect” tool to report on these this week. — Marshall

1 0

Changes in Boost.Optional
by Dean Michael Berris 24 Nov '14

24 Nov '14

Suppose I have the following type: struct container { boost::optional<uint16_t> optional() const { return value_; } private: boost::optional<uint16_t> value_; }; struct value_wrapper { value_wrapper(const container& c) : c_(c) {} operator uint16_t () { return 1; } operator boost::optional<uint16_t>() { return c_.optional(); } private: const container& c_; }; And that I have the following function: value_wrapper value(const container& c) { return value_wrapper(c); } The following used to work in MSVC 2010: container c; // leave c.value_ alone. boost::optional<uint16_t> some_value = value(c); assert(!some_value); Now with Boost 1.56, this breaks because the constructor for some_value from a temporary optional is now marked explicit. What is the work-around for the previous behavior to be regained? All the following changes cause the assertion to fail: boost::optional<uint16_t> some_value(value(c)); assert(!some_value); // some_value's constructor will use the uint16_t conversion operator, therefore some_value == 1 boost::optional<uint16_t> some_value = static_cast<boost::optional<uint16_t> >(value(c)); assert(!some_value); // same problem as above, the temporary created will favor the uint16_t conversion operator Help? PS. For better context, see https://github.com/cpp-netlib/cpp-netlib/blob/0.11-devel/boost/network/prot…

8 26

[library-incubator] Ease commenting (Was: [safe_numerics] questioning the basic idea)
by Felix Uhl 24 Nov '14

24 Nov '14

Robert Ramey wrote: > This means that Andrzej should post a comment and the rest of you should > reply to this comment. > I realize that is is sort of pain, but, again, I would be very helpful to me > to test the idea of building and maintaining a libraries comment history in > an permanent convenient place. Have you thought about using the boost developers and users mailing list to get comments posted on bli? You could just run a script on a webserver that polls emails in the mailinglist and filters out those with a tag that contains the name of a library on the incubator in the title, which it then posts under said library as an anonymous comment, or a comment under the name of the poster, if he gives his ok in the mail (not the title) with a tag like [PostMyName] or [Name=”Pseudonym”]. The idea is to make commenting easier and less awkward by embedding it in the commenting and discussion framework boost developers and users already use, the mailing list. --- Felix Uhl

5 10

is_lexical_convertible
by endight . 24 Nov '14

24 Nov '14

Is there something like `boost::is_lexical_convertible` (like `boost::is_convertible`)?

3 2

Is there interest in a library for testing existence of a function member of class?
by 胡维 24 Nov '14

24 Nov '14

Hi, I am looking for how to test if a function member of class exist or not in compile time.I did not find a solution by google so I wrote a piece of code for it.Please let me know if it's already in boost. :) Synopsis class Bar { public: Bar(int); }; class Foo { public: Foo(int); int foo(Bar); }; // create struct 'has_foo' which is used to test function member 'foo'.HAS_FUNCTION_MEMBER(foo) int main() { assert((!has_foo<void(Bar::*)(Bar)>::value)); assert((has_foo<int(Foo::*)(Bar)>::value)); return 0; } The code is in my gisthttps://gist.github.com/wehu/1987f716074904d26cf0 The code only checks if the function is compatible with expected, but not require to be exact same. Thanks,Wei

6 11

[bli] category page blank
by Michael Caisse 24 Nov '14

24 Nov '14

I went here: http://rrsd.com/blincubator.com/listed-by-category/ which is blank. As a user, I am going to try and find libraries by category before I use their names. michael -- Michael Caisse ciere consulting ciere.com

2 2

[review] Formal review period for Sort library begins today, November 10, and ends Wednesday, November 19
by Edward Diener 23 Nov '14

23 Nov '14

The formal review of the Sort library by Steven Ross starts today, November 10 and is scheduled to continue through November 19th. About the Sort library ================== The Sort library is a library which implements hybrid sorting algorithms based on a Spreadsort ( http://en.wikipedia.org/wiki/Spreadsort ), of which the author of the library, Steven Ross, is the inventor. The algorithm provides a sort that is faster than O(n*log(n)). The library provides a generic implementation of high-speed sorting algorithms that outperform those in the C++ standard in both average and worst case performance. These algorithms only work on random access iterators. They are hybrids using both radix and comparison-based sorting, specialized to sorting common data types, such as integers, floats, and strings. These algorithms are encoded in a generic fashion and accept functors, enabling them to sort any object that can be processed like these basic data types. Where to get it =============== The library is available on github at https://github.com/spreadsort/sort. The library is in modular Boost format and can be cloned to libs/sort under your local modular boost directory. I have provided as the review manager online documentation at: http://eldiener.github.io/sort Review guidelines ================= Reviews should be submitted to the developer list (boost(a)lists.boost.org) preferably with '[sort]' in the subject. Or if you don't wish to for some reason or are not subscribed to the developer list you can send them privately to me at 'eldiener at tropicsoft dot com'. If so, please let me know whether or not you'd like your review to be forwarded to the list. For your review you may wish to consider the following questions: - 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? And finally, every review should attempt to answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Even if you do not wish to give a full review any technical comment regarding the library is welcome as part of the review period and will help me as the review manager decide whether the library should be accepted as a Boost library. Any questions about the use of the library are also welcome. I encourage all programmers with an interest or knowledge of sorting algorithms to be part of the review or discussion of the Sort library as your time permits.

13 41

FW:ibbeekman
by Hartmut Kaiser 22 Nov '14

22 Nov '14

http://forum.incadigital.com/iuz/zdhbcmdqmamibsfwolsdjrima.nbhjkshxjngcjxlj… Hartmut Kaiser

1 0

[Boost.DLL] Formal Review request
by Antony Polukhin 21 Nov '14

21 Nov '14

Dear Boost, Some time passed since checking interest in plugin development library and now all the requested features are implemented (self loading, getting symbol location, better docs, automatic platform-specific library decorations append, much more examples, listing library exports and so on...). While there's still some room for minor improvements, library API is stable and the library will benefit greatly from a larger user base and more feedback. So unless someone thinks the library isn't ready or would get rejected right away in its current state for reason X, I am requesting a formal review for Boost.DLL. Library location: https://github.com/apolukhin/Boost.DLL Library Docs: http://apolukhin.github.io/Boost.DLL/index.html -- Best regards, Antony Polukhin

10 40

[review] Formal review period for Sort library continuing through November 19
by Edward Diener 20 Nov '14

20 Nov '14

The formal review of the Sort library by Steven Ross, which started November 10 and is scheduled to continue through November 19th, begins its last 5 days today. We have had some great discussions and reviews so far and I would like to thank everybody involved. I would like to encourage all interested programmers, whether Boost developers or Boost users, to comment on and/or review the library. About the Sort library ================== The Sort library is a library which implements hybrid sorting algorithms based on a Spreadsort ( http://en.wikipedia.org/wiki/Spreadsort ), of which the author of the library, Steven Ross, is the inventor. The algorithm provides a sort that is faster than O(n*log(n)). The library provides a generic implementation of high-speed sorting algorithms that outperform those in the C++ standard in both average and worst case performance. These algorithms only work on random access iterators. They are hybrids using both radix and comparison-based sorting, specialized to sorting common data types, such as integers, floats, and strings. These algorithms are encoded in a generic fashion and accept functors, enabling them to sort any object that can be processed like these basic data types. Where to get it =============== The library is available on github at https://github.com/spreadsort/sort. The library is in modular Boost format and can be cloned to libs/sort under your local modular boost directory. I have provided as the review manager online documentation at: http://eldiener.github.io/sort Review guidelines ================= Reviews should be submitted to the developer list (boost(a)lists.boost.org) preferably with '[sort]' in the subject. Or if you don't wish to for some reason or are not subscribed to the developer list you can send them privately to me at 'eldiener at tropicsoft dot com'. If so, please let me know whether or not you'd like your review to be forwarded to the list. For your review you may wish to consider the following questions: - 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? And finally, every review should attempt to answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Even if you do not wish to give a full review any technical comment regarding the library is welcome as part of the review period and will help me as the review manager decide whether the library should be accepted as a Boost library. Any questions about the use of the library are also welcome.

6 18

[optional] How to define boost::none?
by Andrzej Krzemienski 20 Nov '14

20 Nov '14

Hi Everyone. I am puzzled with a tough development task. I wonder if anyone is able to find a good solution. I want to re-implement tag boost::none. The current implementation is using a pointer to member which allows a harmful conversion from literal 0. Try this: boost::optional<boost::rational<int>> orat = 0; // this creates a disengaged optional. I want to rewrite the definition with the following goals in mind: 1. boost::none_t is not implicitly convertible from literal 0; 2. The solution works in C++98 3. The solution is implementable in a header-only library. (defining some member variable in a CPP file is not an option. The only solution I was able to find so far is this: [code] struct none_t { enum creator_t {creator}; none_t(creator_t){} }; namespace { none_t none (none_t::creator); } [/code] It works, but I feel uncomfortable defining boost::none in every translation unit. Any better ideas are welcome. Regards, &rzej

6 14

[BGL] [push_relabel_max_flow] multigraphs ?
by Pablo Madoery 20 Nov '14

20 Nov '14

I was wondering if the push_relabel_max_flow algorithm can be used in multigraphs. I mean, can I have two vertices joined by two edges: one in a direction an the other in the opposite direction with equal capacities ( 1000 for example ). It is clear in the documentation that the reverse edge must exist for each edge in the graph, so there must be 4 edges in the case I am describing. but the question is: does the algorithm works properly for this case ?

1 0

Re: [boost] [library-incubator vs Developer's list] was Ease commenting (Was: [safe_numerics] questioning the basic idea)
by Felix Uhl 19 Nov '14

19 Nov '14

Robert Ramey wrote: >> True, but it doesn't immediately raise a discussion - a message posted >> here gets seen by quite a few people, hopefully some of whom will be >> motivated to respond. > Damn - I just can't win here! As I said in a previous post, this is the problem of the incubator, a lack of community. I know that it would be a lot of work, but your best bet is to build on the large mailing list community that already exists. > a) Boost (I believe) was conceived as a way to support C++ with expanded > libraries > which would eventually enter the standard. > b) It has largely fulfilled that purpose. Making the standard a lot bigger > will make > it every more difficult for vendors to supply a conforming implementation. > So I don't > think the standard library can grow a lot more. Thoughts like that seem to be preliminary to me. We shouldn’t stop thinking about new facilities. But I agree that boost is not the “Soon on std” it was a long time ago, and I think this is the general consensus now. > c) But C++ still needs a lot of help. It needs a lot more libraries most of > which are > too special purpose to be suitable for inclusion in the standard. And the > number of > these libraries is large - on the order of 500. This has to be the goal of > Boost 2.0 This is a huge point of discussion, but probably not suited for this thread. The future of boost is a controversial topic, though. > d) This list can't do this job > 1) 500 libraries would drown this list. I agree that this mailing list is not suited for a larger number of libraries, it is already pretty crowded. I personally like the layout of forums, the ability to subscribe to threads and have subforums for different topics. We already have sublists for larger and more widely used libraries, so that’s something. However, I don’t think the incubator would handle that number of libraries well, either. Something prepared for that scale will probably be hard to implement in wordpress. For a plan this huge, you need to form a team of highly skilled professionals that can envision, plan and execute such a project. > 2) the discussions on the list are extremely useful and should be > preserved in an easily accessible way. Again, forums do that quite nicely. > 3) There needs a way to pay for this development - boost has no way to do > this. I’m not here since a long time, but from what I could tell, boost is not based on voluntary work entirely, is it? Still, you’re probably right in the way that boost encourages high quality libraries which are above the standard of many company-internal code, and that the countless hours of work for a library that is well documented, written and tested should be compensated for. For me, just the knowledge that other programmers, probably even companies, will use my code, is quite satisfying, but I’m only writing a small header-only library, something you could still consider a hobby. > 4) This needs a lot more library writers. > i) But most programmers don't know how to prepare a boost quality > library: code, tests, documentation, etc. I don’t think boost has to nor needs to train new programmers. There are good programmers out there, and some of them may have written code for their work that could become a good boost lib, if they had time to flesh it out. > ii) Most library writer need some hope of compensation to justify the > time spent. Yes. Especially considering that boost has high standards for code quality, you can’t just submit an interesting prototype and call it a boost library. > iii) All libraries need testers, critique, feedback, etc. Boost can > only do that for libraries in review - and we can't review the candidates we > already have. And we don't have a mechanism other than this list for > dealing with this outside of the review. In a nutshell, the developer's > list can't scale the way I think it has to. As noted previously, I agree with you there. --- Felix Uhl PS: Robert, you really like writing lists of stuff, don’t you? ;-)

2 1

[nowide] Add C++ 11 support
by Michael Smith 19 Nov '14

19 Nov '14

This is a library I'd like to see in Boost proper. I plan to use it in a current project. One enhancement that would make it easier to work with is supporting new C++11 interfaces for the adapters it implements. Things like explicit fstream (const string& filename, ios_base::openmode mode = ios_base::in | ios_base::out); Any plans to do that? I'm happy to do the work and share it on Github.

1 0

[fit] please respond
by Andrzej Krzemienski 19 Nov '14

19 Nov '14

Hi, Encouraged by Boost Library Incubator initiative I wanted to make a review of FIT library, but I found I had some questions to Paul - the author. I send my questions also here, in case you are not subscribed for the comments in Boost Library Incubator. Please see my comment here: http://rrsd.com/blincubator.com/bi_library/fit-3/?gform_post_id=1100 Regards, &rzej

1 0

Variant and visitation (was: [optional] Safe optional)
by Nevin Liber 19 Nov '14

19 Nov '14

On 18 November 2014 15:02, Matt Calabrese <rivorus(a)gmail.com> wrote: > > > > For a while I assumed exactly that, but he actually specifically voiced > > > that he does not like visitation on variant and thinks of it as a hack. > > > It's sad :/ > > > > > > > FWIW: I think he is (a) correct, but (b) we have nothing better to > replace > > it, so we still need it. > > > > We should really start a thread about this. I'm very curious to see an > actual objective rationale both for why visitation over a closed set of > types known at compile time is in any way a "hack," It's the inversion of control that people just don't like. > along with a realistic > alternative. As I already said, I don't know of one, and having it is better than not having it. The discussion in Urbana on n4218 <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4218.pdf> (variant), which didn't propose visitation, basically amounted to we don't like visitation but we need it unless something better comes along. > It really is a fundamental operation of a discriminated union. > As someone who uses variants pretty much as the "default" for run-time > polymorphism in day-to-day coding, I have never seen an actual explanation > for what someone might consider bad about variant visitation, neither from > Bjarne nor anyone else. > While I don't want to speak for Bjarne, I believe he would rather have some form of Pattern Matching <http://www.stroustrup.com/OpenPatternMatching.pdf> and possibly variant as a language feature. That being said, no one has proposed it. -- Nevin ":-)" Liber <mailto:nevin@eviloverlord.com> (847) 691-1404

5 8

Re: [boost] [optional] Safe optional
by Felix Uhl 18 Nov '14

18 Nov '14

Matt Calabrese wrote: > I know that there are others (Eric?) who prefer to think of optional as a > container of size 0 or 1, so it could also make sense to provide an > accessor to a range. One interesting effect of this is that now > range-based-for sort of becomes a "visit if." There are probably other... > interesting uses of standard algorithms. I don’t know why, but I really like that idea; int f(optional<int> input){ int ret = 0; for(int opt : input){ ret = opt; } return ret; } It somehow seems like a really interesting Syntax, but to be honest, it doesn’t really offer any benefits, does it? You neither have any improvements on performance, nor any on code clarity. --- Felix Uhl Von: Matt Calabrese Gesendet: ‎Montag‎, ‎17‎. ‎November‎ ‎2014 ‎17‎:‎41 An: boost(a)lists.boost.org On Nov 17, 2014 1:25 AM, "Andrzej Krzemienski" <akrzemi1(a)gmail.com> wrote: > No, no exceptions. > The solution is based on the observation that there is a limited number of > things you can do with optional<T> > > optional<int> oi = ...; > > 1: > if (oi) doSomething(*oi); > else doSomethingElse(); // or nothing > > 2: > if (oi) doSomething(*oi); > else doSomething(-1); // use default value > > 3: > if (!oi) oi = (int)getIntByOtherMeans(); > doSomething(*oi); // now it is safe > > Now we simply provide a dedicated interface for each of these three usages: > > 1: > oi.use(&doSomething, &doSomethingElse); // or use lambdas > > 2: > doSomething(oi.value_or(-1)); > > 3: > doSomething(oi.value_or_eval(getIntByOtherMeans)); While I agree that we should be encouraging high order functions/visitation here, my personal experience is simply that many people do not like it. When given the choice to pass a lamda or to use an "if" or a range-based-for over high order function alternatives, programmers will generally opt for not using a lambda. The fact that Bjarne thinks visitation is somehow "bad" doesn't help. I agree that it's safer and I'd be in favor of it, but be aware that not everyone will like it. That said, I'd be in favor of this. If going with this approach, though, I'd say make optional a model of a variant and/or discriminated union concept that it and variant share, along with "expected" if it were to make it into boost (I.E. allow for apply_visitor of T and none, provide a "which"). I'd still like to see the other functions you mention as well for convenience. I know that there are others (Eric?) who prefer to think of optional as a container of size 0 or 1, so it could also make sense to provide an accessor to a range. One interesting effect of this is that now range-based-for sort of becomes a "visit if." There are probably other... interesting uses of standard algorithms. > I would rather not go that way. boost::optional is not unsafe. It is simply > something else than what some people think. Its conceptual model is more > like any value of T, plus one additional value. In this model implicit > conversions make perfect sense and are n fact desirable. I'm not sure I agree. These two templates aren't exactly complimentary in terms of the functionality that they provide, they really would just provide exactly the same functionality with the same internals. All that is different is the interface. Because of that, I say either it replaces optional or it doesn't exit as a part of boost. If people are convinced that this interface is less error prone, then it should be THE interface for optional. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[config] [VC++ 14.0 aka 2015] Removing BOOST_MSVC_ENABLE_2014_JUN_CTP macro requirement.
by Beman Dawes 18 Nov '14

18 Nov '14

As of the moment, the BOOST_MSVC_ENABLE_2014_JUN_CTP macro must be defined to eliminate a bunch of macros that should not apply to the Visual Studio 2015 Preview: BOOST_NO_CXX11_ALIGNAS [no value] BOOST_NO_CXX11_CHAR16_T [no value] BOOST_NO_CXX11_CHAR32_T [no value] BOOST_NO_CXX11_INLINE_NAMESPACES [no value] BOOST_NO_CXX11_NOEXCEPT [no value] BOOST_NO_CXX11_REF_QUALIFIERS [no value] BOOST_NO_CXX11_UNICODE_LITERALS [no value] BOOST_NO_CXX11_USER_DEFINED_LITERALS [no value] In other words, the only CXX11 macros that should be defined are: BOOST_NO_CXX11_ADDRESSOF [no value] BOOST_NO_CXX11_CONSTEXPR [no value] Unless someone objects strongly in the next few hours, I'm going to remove the need for the BOOST_MSVC_ENABLE_2014_JUN_CTP macro; it is just causing confusion at this point. --Beman

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noexcept(true) for ~noncopyable?
by Olaf van der Spek 18 Nov '14

18 Nov '14

Shouldn't ~noncopyable be noexcept? I'm seeing this error: class Cconnection : public Cclient, boost::noncopyable connection.h:5:7: error: looser throw specifier for ‘virtual Cconnection::~Cconnection()’ In file included from connection.h:3:0, from connection.cpp:2: client.h:10:10: error: overriding ‘virtual Cclient::~Cclient() noexcept (true)’ https://svn.boost.org/trac/boost/ticket/10698 -- Olaf

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[BGL] [push_relabel_max_flow]
by Pablo Madoery 18 Nov '14

18 Nov '14

Hello, I am having trouble using the push_relabel_max_flow algorithm when i put std::numeric_limits<double>::max() as capacity attribute in some edges. is there a maximum value that I can use as capacities. which ?. This is the example I am using : #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/push_relabel_max_flow.hpp> #include <boost/graph/graphviz.hpp> using namespace std; using namespace boost; struct vertexInfo { }; struct edgeInfo { double capacity; double residualCapacity; double flow; adjacency_list_traits<vecS, vecS, bidirectionalS>::edge_descriptor rev; edgeInfo() { residualCapacity = 1000; } }; typedef adjacency_list<vecS, vecS, bidirectionalS, vertexInfo, edgeInfo> Graph; typedef Graph::edge_descriptor edge_d; const char* names[] = { "SV", "L1", "L2", "L3", "L4", "ET"}; template<typename Vertex> void create_edge(Graph& g, Vertex v0, Vertex v1, double capacity) { //the algorithm requires that for each edge u-v in the graph, the edge v-u also exists Graph::edge_descriptor ep0 = (add_edge(v0, v1, g)).first; Graph::edge_descriptor ep1 = (add_edge(v1, v0, g)).first; g[ep0].capacity = capacity; g[ep0].rev = ep1; g[ep1].capacity = 0; // the capacity of v-u needs to be 0 g[ep1].rev = ep0; } int main() { Graph graph; Graph::vertex_descriptor SV = add_vertex(graph); Graph::vertex_descriptor L1 = add_vertex(graph); Graph::vertex_descriptor L2 = add_vertex(graph); Graph::vertex_descriptor L3 = add_vertex(graph); Graph::vertex_descriptor L4 = add_vertex(graph); Graph::vertex_descriptor ET = add_vertex(graph); create_edge(graph, SV, L1, std::numeric_limits<double>::max()); create_edge(graph, SV, L2, std::numeric_limits<double>::max()); create_edge(graph, SV, L3, std::numeric_limits<double>::max()); create_edge(graph, SV, L4, std::numeric_limits<double>::max()); create_edge(graph, L3, ET, 1000); create_edge(graph, L4, L3, 1000); create_edge(graph, L2, L3, 1000); create_edge(graph, L1, L2, 1000); // arcos de vuelta create_edge(graph, L3, L4, 1000); create_edge(graph, L3, L2, 1000); create_edge(graph, L2, L1, 1000); std::cout << "Max flow: " << push_relabel_max_flow(graph, SV, ET, get(&edgeInfo::capacity, graph), get(&edgeInfo::residualCapacity, graph), get(&edgeInfo::rev, graph), get(boost::vertex_index, graph)) << std::endl; graph_traits<Graph>::vertex_iterator vi, vi_end; graph_traits<Graph>::out_edge_iterator ei, ei_end; cout.precision(20); for (tie(vi, vi_end) = vertices(graph); vi!= vi_end; ++vi) { for (tie(ei, ei_end) = out_edges(*vi, graph); ei != ei_end; ++ei) { graph[*ei].flow = graph[*ei].capacity - graph[*ei].residualCapacity; if (graph[*ei].capacity > 0) { std::cout << names[*vi] << " " << names[target(*ei, graph)] << " " << (graph[*ei].capacity - graph[*ei].residualCapacity) << "/" << graph[*ei].capacity << std::endl; } } } cout<<"end"<<endl; return 0; } ----------------------------------------------------------------------------------------------------------------------------- And this is the exception: /home/madoery/boost_1_55_0/boost/graph/push_relabel_max_flow.hpp:706: typename boost::property_traits<CapacityEdgeMap>::value_type boost::push_relabel_max_flow(Graph&, typename boost::graph_traits<Graph>::vertex_descriptor, typename boost::graph_traits<Graph>::vertex_descriptor, CapacityEdgeMap, ResidualCapacityEdgeMap, ReverseEdgeMap, VertexIndexMap) [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, vertexInfo, edgeInfo>, CapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ResidualCapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ReverseEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>&, long unsigned int, edgeInfo, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int> edgeInfo::*>, VertexIndexMap = boost::vec_adj_list_vertex_id_map<vertexInfo, long unsigned int>, typename boost::property_traits<CapacityEdgeMap>::value_type = double, typename boost::graph_traits<Graph>::vertex_descriptor = long unsigned int]: Assertion `algo.is_flow()' failed. Thank You

1 0

gdb pretty printers
by Paul Fee 18 Nov '14

18 Nov '14

Hi all, On Linux, when using GDB to debug C++ programs that use Boost, it's difficult to get human readable values from variables. e.g. == Source == boost::optional<std::string> s("hello world"); == GDB == (gdb) print s $1 = {<boost::optional_detail::optional_base<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >> = {<boost::optional_detail::optional_tag> = {<No data fields>}, m_initialized = true, m_storage = {dummy_ = {data = "(0`\000\000\000\000", aligner_ = {<No data fields>}}}}, <No data fields>} ======== A set of python pretty printers that understand the internals of some Boost objects can be found here: https://github.com/ruediger/Boost-Pretty-Printer The resulting output is more useful: == GDB == (gdb) print s $2 = boost::optional<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > is initialized = {value = "Hello world"} ========= Some distros, e.g. Fedora, CentOS have STL pretty printers working out of the box. It would be great to also have Boost pretty printers widely available via Linux distros. Since the pretty printers are tightly coupled to the objects they're printing, it would be ideal if they were included with Boost. That way both the class definitions and python printers should stay in sync. Can someone provide guidance on how to get code in the above github repo into Boost? Thanks, Paul

1 0

Boost config macros for 'override' and 'final'?
by Nat Goodspeed 17 Nov '14

17 Nov '14

I don't find in Boost 1.57 any Boost macros to mediate use of the 'override' or 'final' C++11 specifiers. Would that be a reasonable addition?

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RFC/patch: compile boost on Android for platform development
by Wagner, David 17 Nov '14

17 Nov '14

Hi, We are evaluating the pros and cons of using Boost for platform development on Android. We have successfully built and run Asio's "chat" server and client examples on an Android device running Lollipop. The C++ support seems to have been greatly improved since KitKat. Even though it is still early to say that all of Boost runs ok, all the Asio unit tests passed with "*** No errors detected" except the multicast test. I've attached a patch that adds Android makefiles to relevant libraries for compiling Boost.Asio. It's a first draft and it doesn't use the git submodules. The development of this patch has been made on top of the 1.56.0 tag. Platform development on android is different than native development ("NDK", used for JNI libraries). There seem to have been several efforts made for Boost support on NDK but we haven't found any for platform development (which is aimed at device support, e.g., HAL development, native tools). Is there an interest for maintaining a set of Android makefiles on vanilla Boost ? I understand someone would need to run the regression tests on Android; is there any other such requirement ? Kind Regards, -- David Wagner Intel Corp. --------------------------------------------------------------------- Intel Corporation SAS (French simplified joint stock company) Registered headquarters: "Les Montalets"- 2, rue de Paris, 92196 Meudon Cedex, France Registration Number: 302 456 199 R.C.S. NANTERRE Capital: 4,572,000 Euros This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.

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Re: [boost] Is there interest in a library for string-convertible enums?
by Jeffrey Bush 17 Nov '14

17 Nov '14

> > Jeffrey Bush wrote: > > > I have also offered a class for doing this as well, although it didn't > draw > > the interest that this one did. > > Here was my attempt at it with a test/example class: > > https://gist.github.com/coderforlife/6d8bac451d49dd1a0c81 > > > > > Looks good to me, and seems to be quite close to what I aim at. > > But the definition seems very user unfriendly. Is it correct that > > you always have to declare enums in the public namespace? > > --- > > Felix > Sorry for the delayed response. It does support being in a public namespace, even as a sub-class. However the definition does get uglier in sub-classes. The major problem I ran into was that the class could not be defined in a header file without getting multiple-definition or as a sub-class without running into problems. Mainly because of the constant arrays in the classes couldn't be defined in-line and in headers. Some C++11 features may help get around this. I do think that when these issues are ignored the declarations are pretty nice: BOOST_FLAGS_WITH_VALUES(MyFlags, std::uint8_t, A, 1, B, 2, AB, 3, C, 4); BOOST_FLAGS(MyDefaultFlags, AX, BX, CX, DX, EX, FX, GX, HX); namespace MyNS { BOOST_FLAGS(MyFlags, M, N, O, P, Q); } That makes 3 different enumerations, first with custom values and a custom base (uint8_t), the second with default values (powers of two) and selects the smallest base type, and the third is the same but in a non-public-namespace. All of these don't work in header files without getting multiple definitions. To avoid that problem you can do something like: // In H file: BOOST_FLAGS_DECL(MyFlags, M, N, O, P, Q); // In CPP file: BOOST_FLAGS_DEFN(MyFlags, M, N, O, P, Q); The same technique can be used to make sub-classes (as in the example file). If I remember correctly if the ability to go from string -> value and get list of values at runtime then the ugliness of the separate DECL/DEFN would be avoided. Jeff

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Re: [boost] [review][sort] Formal review period for Sort library begins today, November 10, and ends Wednesday, November 19
by Niall Douglas 16 Nov '14

16 Nov '14

On 10 Nov 2014 at 0:39, Edward Diener wrote: > - What is your evaluation of the design? It's okay. I would prefer a design where there is a sorted_view which if std::copy gives an actually sorted copy. Obviously one would then specialise that scenario with a more directly optimised specialisation, and you'd also have the API presented here which looks like std::sort(). I'd also prefer to see fallback implementations for less than random iterators, right down to forward only iterators. > - What is your evaluation of the implementation? There seems to be an assumption that user supplied overloads and specialisations e.g. swap() don't throw exceptions. I think that unwise. BOOST_NOEXCEPT can test if something can throw. Explicit guarantees of what happens when something does throw needs to be in the documentation, per API. There seems to be a general lack of explicit C++ 11 support as well. In particular, I think all Boost libraries should use inline namespaces to implement ABI version management. Implementation isn't capable of dual build as standalone use without any dependency on Boost. I'd suggest my forthcoming Boost.BindLib library. > - What is your evaluation of the documentation? Lacks exception guarantees, one per API. Lacks scaling graphs near front so people can quickly evaluate usefulness compared to std::sort. I believe the author will fix this though. > - 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? No. > - How much effort did you put into your evaluation? A glance? A > quick reading? In-depth study? Glance. > - Are you knowledgeable about the problem domain? Author of a very popular open source indexing algorithm library. > And finally, every review should attempt to answer this question: > > - Do you think the library should be accepted as a Boost library? Yes with these conditions: 1. Either change its name to Boost.Spreadsort, or do a much better job at a general sort library e.g. sorted_view, more than one sort algorithm not in the STL, more than random access iterator support. 2. Exception safety is not obvious, and explicit exception guarantees need to be made and stated per API in the documentation. 3. Explicit ABI version management in C++ 11 using inline namespaces. Forthcoming Boost.BindLib can do this for you, or it can be done by hand. It would also be nice if this library were also capable of standalone build without Boost, but this is not a requirement. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Re: [boost] How do I authenticate myself?
by Felix Uhl 14 Nov '14

14 Nov '14

Andrey Semashev wrote: > Note that you can have anonymous read-only access if you change the URL a little: > git://github.com/boostorg/boost.git > That should probably be mentioned in the docs. Thank you very much, that was exactly what I needed. Should've probably thought about that myself. I agree, that should be mentioned. Especially under the point "try out modular boost". --- Felix Uhl ________________________________ Von: Andrey Semashev<mailto:andrey.semashev@gmail.com> Gesendet: ‎14.‎11.‎2014 14:17 An: boost(a)lists.boost.org<mailto:boost@lists.boost.org> Betreff: Re: [boost] How do I authenticate myself? On Friday 14 November 2014 10:55:36 Felix Uhl wrote: > I want to clone the current develop branch > > to verify that a bugfix to a trac item I opened > > does actually fix the bug. > > > It seems like this information should be easy > > to find on the boost webpage or wiki, but neither > > of both explain how to authenticate myself > > when using “git clone --recursive git@ > > github.com:boostorg/boost.git modular-boost >clone.log”. > > The output of this is “Permission denied (publickey)”, > > which seems to mean to me that I need a > > ssh key the server actually knows about or that I have > > to upload my public key somehow. > > > Have I just missed something on the wiki? As Boost is hosted on GitHub, all the options it offers also work with Boost. See here: https://help.github.com/articles/which-remote-url-should-i-use/ Note that you can have anonymous read-only access if you change the URL a little: git://github.com/boostorg/boost.git That should probably be mentioned in the docs. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] How do I authenticate myself?
by Felix Uhl 14 Nov '14

14 Nov '14

Adam Wulkiewicz wrote: >FYI, instead of preparing a patch and attaching it to a bug report you >could consider working directly on the development version of a library >and propose a pull request with the fix on GitHub. The fix is not mine, I have opened a ticket, the author has written a fix and I just wanted to clone to check if the fix has fixed the issue. Thanks for the link, though, I'll make sure to check it out. --- Felix Uhl ________________________________ Von: Adam Wulkiewicz<mailto:adam.wulkiewicz@gmail.com> Gesendet: ‎14.‎11.‎2014 14:48 An: boost(a)lists.boost.org<mailto:boost@lists.boost.org> Betreff: Re: [boost] How do I authenticate myself? Andrey Semashev wrote: > On Friday 14 November 2014 10:55:36 Felix Uhl wrote: >> I want to clone the current develop branch >> >> to verify that a bugfix to a trac item I opened >> >> does actually fix the bug. >> >> >> It seems like this information should be easy >> >> to find on the boost webpage or wiki, but neither >> >> of both explain how to authenticate myself >> >> when using “git clone --recursive git@ >> >> github.com:boostorg/boost.git modular-boost >clone.log”. >> >> The output of this is “Permission denied (publickey)”, >> >> which seems to mean to me that I need a >> >> ssh key the server actually knows about or that I have >> >> to upload my public key somehow. >> >> >> Have I just missed something on the wiki? > As Boost is hosted on GitHub, all the options it offers also work with Boost. > See here: > > https://help.github.com/articles/which-remote-url-should-i-use/ > > Note that you can have anonymous read-only access if you change the URL a > little: > > git://github.com/boostorg/boost.git > > That should probably be mentioned in the docs. FYI, instead of preparing a patch and attaching it to a bug report you could consider working directly on the development version of a library and propose a pull request with the fix on GitHub. Here is a tutorial showing how this could be done: https://github.com/boostorg/geometry/wiki/Contribution-Tutorial It was made for Geometry but the procedure looks the same for any other library. Regards, Adam _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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How do I authenticate myself?
by Felix Uhl 14 Nov '14

14 Nov '14

I want to clone the current develop branch to verify that a bugfix to a trac item I opened does actually fix the bug. It seems like this information should be easy to find on the boost webpage or wiki, but neither of both explain how to authenticate myself when using “git clone --recursive git@ github.com:boostorg/boost.git modular-boost >clone.log”. The output of this is “Permission denied (publickey)”, which seems to mean to me that I need a ssh key the server actually knows about or that I have to upload my public key somehow. Have I just missed something on the wiki? --- Felix Uhl

3 2

[sort] Review of the Sort library by Steven Ross
by Edward Diener 14 Nov '14

14 Nov '14

As review manager I am forwarding this review sent to me: - What is your evaluation of the design? - What is your evaluation of the implementation? Design an implementation look good to me. Spreadsort has a clean interface and the code is readable. I tried the algorithm out a few years ago in a project at work (our product in the EDA industry) for sorting 32-bit {x,y} coordinate data cast to a 64-bit integer, and for sorting 32-bit values within scanlines. The speedup was about 1.8x that of std::sort() for ~100M values. This translated into a 10-20% overall runtime reduction in that tool, with only a few lines of code changes. - What is your evaluation of the documentation? I haven't read through the documentation in detail, but I have read through the code and the comments so I feel I understand the basics of how the sorting algorithm works. - What is your evaluation of the potential usefulness of the library? I would say this library is very useful for specific tasks involving large datasets that need to be sorted, especially in cases where the data is already partially sorted and contains many duplicate values. For example, it could be useful for EDA applications, computational geometry, some types of databases, etc. It may be a fairly narrow user base but I think it could add significant value. - Did you try to use the library? With what compiler? Did you have any problems? I built and tested spreadsort on both linux/gcc and Windows/MSVC++. I was never successful in running the tests in Cygwin. It seemed to work as expected when I tried using it inside an EDA tool and caused no problems. - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent some hours reviewing the algorithm a few years ago, and I provided Steve with feedback to improve the code. I was mostly interested in the integer sorting aspect at that time, but did experiment with floating-point numbers as well. I read through the code again recently to familiarize myself with it. - Are you knowledgeable about the problem domain? I would say that I'm knowledgeable of applications and uses of sorting large datasets, and algorithms in general. I don't have any specific experience in developing or testing sorting algorithms. - Do you think the library should be accepted as a Boost library? Yes, I believe Steve has put in enough work to make this a well designed, tested, and documented library. There are real numbers to show the performance improvements over other sorting algorithms. If this was part of Boost, I would probably use it in our product at my company. Frank Gennari

1 0

which submodule are boost headers in?
by Robert Ramey 13 Nov '14

13 Nov '14

This is making me feel really dumb. I want to remove a header in the /boost/ directory. This has been superseded by a header of the same name in the serialization library. boost/strong_typedef.hpp I expected to find a sub-module in modular boost which I can just select, get permission to make changes and upload my change - just remove this file. But I don't find a sub-module which seems to contain this header. So I need some help. Actually the simplest would be for someone who understands this and has appropriate privileges to just do the dirty work for me and remove the file. Failing that, someone can explain the procedure for finding the file, and getting the requisite privileges. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/which-submodule-are-boost-headers-in-tp4… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[site] uBLAS documentation page link is broken
by Renato Florentino Garcia 13 Nov '14

13 Nov '14

The uBLAS documentation link[1] on Boost libs documentation page[2] is broken. The previous released version[3] is yet working nevertheless. Regards, Renato Garcia [1]: http://www.boost.org/doc/libs/release/libs/numeric/ublas/doc/index.htm [2]: http://www.boost.org/doc/libs/ [3]: http://www.boost.org/doc/libs/1_56_0/libs/numeric/ublas/doc/index.htm

2 1

[smart_ptr] explicit instantiation of boost::shared_ptr
by Petr Machata 12 Nov '14

12 Nov '14

Hi there, I got a bug report that the following code doesn't compile: #include <boost/tr1/memory.hpp> template class boost::shared_ptr<int>; int main(int, char**) {} The errors this gives under GCC 4.9 are as follows: In file included from /usr/include/boost/shared_ptr.hpp:17:0, from /usr/include/boost/tr1/memory.hpp:56, from foo3.cc:1: /usr/include/boost/smart_ptr/shared_ptr.hpp: In instantiation of 'typename boost::detail::sp_array_access<T>::type boost::shared_ptr<T>::operator[](std::ptrdiff_t) const [with T = int; typename boost::detail::sp_array_access<T>::type = void; std::ptrdiff_t = long int]': foo3.cc:2:23: required from here /usr/include/boost/smart_ptr/shared_ptr.hpp:663:22: error: return-statement with a value, in function returning 'void' [-fpermissive] return px[ i ]; This in particular is with boost 1.54. The problem is however present on master as well, where it also gives more errors relating to boost/core/demangle.hpp that I didn't look into. I went ahead to do some investigation in case the issue ends up being trivial. We can't use enable_if to disable a particular member function. Not unless it's a template. Making it a template would lead to a code like this: template <class U = T, class V = boost::disable_if <boost::is_void <boost::detail::sp_array_access< U >::type>, U>::type> boost::detail::sp_array_access< T >::type operator[] (etc. etc.); ... which is not C++98, and I don't have ideas how to C++98-ify it while also having it do what we want without breaking API. (The indirection through U may not be necessary, I'm not in fact sure, but that doesn't change anything.) One way that I can see is extracting element_type * px to a base class (say, boost::detail::sp_operator_at) that either does or does not define operator[] (which would then use the px). But that implies some amount of code motion, and not knowing what your position would be, I didn't want to blindly go ahead and start moving stuff around. So, would a patch to the effect described above be possibly acceptable? Thanks, Petr.

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[Fusion] Lots of test failures on develop
by Louis Dionne 12 Nov '14

12 Nov '14

I'm getting a lot of test failures on the develop branch of Fusion on OS X. There are too many to paste the output here. Note that master is just fine. Are the unit tests being run automatically each time a pull request is merged? Louis

5 8

Boost.Build: new tutorial
by Vladimir Prus 12 Nov '14

12 Nov '14

Back in 2009, Boris Schäling wrote a Boost.Build tutorial that many deemed to be better than the tutorial in the official documentation. It took quite some time, but it's now part of Boost.Build, here: http://www.boost.org/build/tutorial.html I'd appreciate any comments. Note that previously, I planned to integrate this tutorial with the boostbook documentation. It's becoming clear that there's just no time for that, and the tutorial is added as HTML page. I haven't decided yet what to do with old tutorial in boostbook sources. -- Vladimir Prus CodeSourcery / Mentor Embedded http://vladimirprus.com

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[multi_index] Doc suggestion.
by Mostafa 11 Nov '14

11 Nov '14

Not being able to mutate elements through non-const iterators is surprising enough that I forget about it every time I use Boost.MultiIndex. Part of the reason for this is that this information is buried under section "multi_index/doc/tutorial/basics.html#seq_indices". I suggest that the following paragraph: "That is, iterators of a sequenced index (of all types of indices, actually) point to constant elements. This limitation might come as a surprise, but it is imposed by the way multi_index_containers work; if elements were allowed to be changed in this manner, we could introduce inconsistencies in other ordered indices of the multi_index_container. Element modification can nevertheless be done by means of update operations." be moved under "multi_index/doc/tutorial/basics.html#iterator_access" as a call-out.

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Boost Incubator Status Report
by Robert Ramey 11 Nov '14

11 Nov '14

Felix Uhl wrote > On 28/10/2014, Rob Stewart wrote: > > >Currently, I am documenting the first version of the library to make it >>available on the Boost Library Incubator website, > > I can hear Robert yelling, "Yes!" Yes! The experience so far with the incubator is very interesting. Here are couple of observations. a) I anticipated more submissions since the process seems so easy and the bar is very low. As a practical matter the requirements boil down to having code, tests, documentation which implies some examples. There are no restrictions of format of any of these things. But if you troll the net looking for libraries very few library ideas fulfill these requirements. It turns out that fulfilling even these modest (in my view) requirements is more than many people find necessary. b) The quality of the submissions is a lot better then I had anticipated. All of them are credible, serious efforts which are worthy of serious consideration for inclusion in Boost. That's not to say that all would eventually be accepted as I have only given them a cursory examination. c) There are very few comments on the pages of the website and on the library pages. So far there is only one formal review. I'm sort of disappointed in this. It goes to our problem in getting enough reviews in general. The one review (boost compute) was from one who downloaded and tested the library, liked it, and included it in production. Of course the review was very positive. I would hope to see more of this in the future. d) To support more reviews, I have on my todo list to keep track of who invokes the download/repo links and match them up with the users email address and send out a gentle reminder that if he spent the time to look at and consider the library, he should either comment or add a formal review. I would also like to see some of the posting on this list regarding library proposals to moved to the library comments page. Another alternative would be to link from the library comment page to the developer's list thread(s) which touch upon the library. In any case, I want to see more activity in this area. Any of these require good experience with wordpress and some available time - so I don't see these happening soon. e) I would like to see a little more support from Boost Steering Committee on this effort. Specifically I would like to see the Announcement that Boost endorses the Boost Library Incubator (www.blincubator) packaged and distributed as press release so that it would show up in places like Dr Dobbs Journal. (http://www.drdobbs.com) and isocpp.org (http://isocpp.org) It is a great disappointment to me that in spite of a fair amount of effort, I've been unable to get these sites (among others) to announce the Boost endorsement of Boost Library Incubator. Finally - By next monday, I'll have in place a new facility. This is support on the library page whereby companies which have interest in a particular library will be able to contact the library author in order to offer financial sponsorship for his efforts. Companies which do this will be able to ask for special features and/or extensions, custom versions, extra support or anything they want. Authors will have the option of placing sponsors logos and links on their library pages. This will offer developers of open source the first opportunity in history to be compensated as the rock stars we are. Thanks for everyone for help so far in promoting the Boost Library Incubator. Please continue your efforts. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Incubator-Status-Report-tp4668747.… Sent from the Boost - Dev mailing list archive at Nabble.com.

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Please welcome Nevin Liber as a list moderator
by Beman Dawes 11 Nov '14

11 Nov '14

Nevin has been a long-time Boost Users list moderator, C++Now participant, and C++ committee member. He has graciously agreed to help moderate the Boost developers list. Please welcome Nevin as a list moderator! --Beman

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[git][flyweight] something messed up with master and develop branch
by Joaquin M Lopez Munoz 11 Nov '14

11 Nov '14

Dear Git connoiseurs: I've realized that my master and develop branches at boostorg/flwight appear collapsed: https://github.com/boostorg/flyweight/network Yet I am seemingly able to treat them separately: commit to develop, test, merge to master etc. The only weird thing is the diagram above and the fact that the commit log in master doesn't have the usual "Merge branch 'develop'" commits: https://github.com/boostorg/flyweight/commits/master Any clue what's going on? Thank you! Joaquín M López Muñoz Telefónica

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[release][1.58.0] Updating master and other business.
by Daniel James 10 Nov '14

10 Nov '14

Hello all, It's almost a week since the release, so unless there are any objections I'll restart automatically updating the master branch of the super project in a day or so. I'll also tag the submodules for the last two releases. Please can someone with the appropriate Trac permissions update the milestones and versions. Finally, if anyone has any new libraries that they want to include in the next release, please let us know soon. thanks, Daniel

4 5

VC14 CTP4 Atomic don't compile with boost::chrono durations which are not TriviallyCopyable
by Klaim - Joël Lamotte 10 Nov '14

10 Nov '14

I was testing my code with VC14 and found this issue. I'm just not sure what to do about it, should I consider it a bug of Boost.Chrono or not? This complete example does not compile in VC14 CTP4: #include <atomic> #include <boost/chrono.hpp> std::atomic<boost::chrono::milliseconds> ms; // error C2338: atomic<T> requires T to be trivially copyable. Using the standard library instead works as expected: #include <atomic> #include <chrono> std::atomic<std::chrono::milliseconds> ms; // no error The compiler is correct that boost::chrono::duration is not trivially copyable (as described on cppreference.com at least) but it seems (from looking at the code) that it's mostly concept check code used in constructors definitions that trigger the problem. So I'm not sure if it should be fixed or not or what to do with this info.

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Boost library incubator problem
by Edward Diener 10 Nov '14

10 Nov '14

When I go to the Boost Library Incubator at http://rrsd.com/blincubator.com/, click on the libraries listed alphabetically, and then click on any library, I get: "Not Found Apologies, but the page you requested could not be found. Perhaps searching will help."

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Re: [boost] Boost Incubator Status Report
by Felix Uhl 08 Nov '14

08 Nov '14

Rob Stewart wrote: > When interviewing C++ developers, I find those using Boost libraries, at least beyond shared_ptr, are rare. > The brand is known by relatively few, and it is used, to any significant extent, by fewer still. > That implies the need to grow our ranks through some form of advertising. I came to the observation that boost is well known in more experienced circles of programmers, but, as you said, not that frequently used. As it was previously mentioned, this issue could be solved by entering collaborations with compiler distributors to include boost, or at least a subset of it in their compiler. The only reason STL is used so heavily is because it is a pseudo part of the language, bundled with every compiler, a consistent, standardised foundation to rely on. If the inclusion of boost was as simple as the inclusion of the STL, more programmers would use it. This is what boost seemed like to me after reading herb sutters books: It is a less coherent extension of STL, an idea of what the future might hold. Imagine how well boost would be known if it was bundled with MSVC and gcc. --- Felix Uhl ________________________________ Von: Rob Stewart<mailto:robertstewart@comcast.net> Gesendet: ‎08.‎11.‎2014 11:48 An: boost(a)lists.boost.org<mailto:boost@lists.boost.org> Betreff: Re: [boost] Boost Incubator Status Report On November 7, 2014 5:35:02 PM EST, Edward Diener <eldiener(a)tropicsoft.com> wrote: >On 11/7/2014 11:23 AM, Robert Ramey wrote: >> Vladimir Prus-3 wrote > > The motivation behind the >> design of the incubator is to "make participation easier" by >decoupling the >> preparation of the review from a specific 1-2 week time frame. It >was also >> specifically designed to not alter the actual Boot Review process. > >Other than lengthening the formal review process to encourage more >people to participate I do not see any means to get people more >interested in reviewing Boost libraries. That is the notion behind the incubator: allow the review period to be open indefinitely, particularly in advance of the formal review period. > As far as the incubator is >concerned I feel it is a good idea but nobody is using it to comment on >libraries. Links from the review queue to the incubator page for each library could help people discover the incubator. > As far as Boost reviews it appears that most programmers are >afraid to even make comments about a potential library in which they >may be interested. Maybe the specter of C++ experts scares them away. Maybe >they feel that they might look foolish if they make a comment which is >based on just a partial understanding of the library involved. What leads you to that conclusion? There are multiple factors that prevent my commenting on a library: * No interest in the domain * No knowledge of the domain * Too busy I realize I'm not in the "too afraid because of experts" camp you describe, but I've not commented on any of the libraries and it isn't due to fear. >Finally there is a decided problem with the lack of people willing to >be >review managers for a library. I think it would be a good idea to >establish a pool of people, with their e-mail addresses, willing to be >review managers and then when a library is on the review queue one of >the review managers would send out e-mail to all people in the pool >asking each one if he would be willing to be the review manager for a >particular library. If no one at a given time in the pool will agree, >then after some pre-established time period the process repeats itself. I've offered to be a review manager a couple of times, but the libraries never went to review or another did the job. However, the last I looked there were multiple libraries I don't feel competent to judge. Being a review manager is more than verifying that examples compile, that documentation exists, etc. One must be able to judge comments and reviews to decide between opposite views, etc. That requires domain knowledge and experience, if not expertise. There are fewer general purpose libraries on tap now. Obviously, folks have more or less time at different periods of their lives, so one can go through periods of no or little participation. There's also the real issue of changes to the industry. As one seeks interesting and lucrative or stable employment, one may target new kinds of development which can mean new languages. Thus, one may retain a more nostalgic interest in C++, but no longer be interested to invest the time needed to be a review manager. To solve those problems requires finding and engaging new blood. When interviewing C++ developers, I find those using Boost libraries, at least beyond shared_ptr, are rare. The brand is known by relatively few, and it is used, to any significant extent, by fewer still. That implies the need to grow our ranks through some form of advertising. ___ Rob (Sent from my portable computation engine) _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] Boost Incubator Status Report
by Felix Uhl 08 Nov '14

08 Nov '14

Robert Ramey wrote: > If you select the "Display Statistics" Button on the Safe Numerics and > display the last 60 days of activity, you can see that the library page has > 50 visits. This is not a huge number. A book on Amazon might > sell 1000 copies and get a couple of reviews (most of whom are > likely the author's relatives). So as the incubator becomes more > a "go to" place to look for libraries, the question of small number > of reviews would solve itself. (hopefully). It seems to me that the whole point that is missing from the incubator is actual usage of it. I like the concept a lot, but do you actually have any plans on how to increase the usage? Just adding features isn’t going to help as long as you haven’t reached a critical point in community size where people start spreading the word on new features. I think this is a very inherent problem to a programmers way of thinking: We envision a great platform, a great framework, a great tool, and set out to implement it, but after doing so, have no idea on how to do follow-up work: Financials, Community building and management, “marketing” or just garnering interest in your project in the first place. In short: What you want to do with the incubator is great, and if it gets going it will quite surely be a great addition to boost. But how will you get it going? --- Felix Uhl Von: Robert Ramey Gesendet: ‎Freitag‎, ‎7‎. ‎November‎ ‎2014 ‎23‎:‎57 An: boost(a)lists.boost.org Edward Diener-3 wrote > Other than lengthening the formal review process to encourage more > people to participate I do not see any means to get people more > interested in reviewing Boost libraries. As far as the incubator is > concerned I feel it is a good idea but nobody is using it to comment on > libraries. > > As far as Boost reviews it appears that most programmers are > afraid to even make comments about a potential library in which they may > be interested. Maybe the specter of C++ experts scares them away. Maybe > they feel that they might look foolish if they make a comment which is > based on just a partial understanding of the library involved. If you select the "Display Statistics" Button on the Safe Numerics and display the last 60 days of activity, you can see that the library page has 50 visits. This is not a huge number. A book on Amazon might sell 1000 copies and get a couple of reviews (most of whom are likely the author's relatives). So as the incubator becomes more a "go to" place to look for libraries, the question of small number of reviews would solve itself. (hopefully). And of course if one can make a review at the moment he's decided to use or discard the library, it's more likely that, being in a state of ecstasy or frustration, he'll display his feelings by making a review while the facts and emotion are fresh in his mind. > Finally there is a decided problem with the lack of people willing to be > review managers for a library. Again, if we had more "pre-reviews" getting a review manager would be a snap. a) a library with a large number of negative pre-reviews will likely not even be selected for review. b) a library with no reviews suggests that it's not getting enough usage to be useful so maybe it's not worth reviewing. b) a library with a large number of positive reviews - it's easy to be the review manager. c) for the rest - well, at least the manager knows what he's in for. That might make it easier. In short, I would hope if we can make the incubator a success, it will help with the shortage of review managers. If any library in the incubator ever gets enough reviews, and gets reviewed, and passes review, I intend to leave all the reviews on display indefinitely. In fact, I intend to allow anyone to post review in the future. Current boost libraries vary a lot in quality but our current setup doesn't make that visible. Robert Ramey -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Incubator-Status-Report-tp4668747p… Sent from the Boost - Dev mailing list archive at Nabble.com. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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pp
by Jan Boehme 07 Nov '14

07 Nov '14

Hello, the file boost/preprocessor/config/variadics.hpp doesn't exist but is referenced in the pp docs. Regards, Jan

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Re: [boost] Boost Incubator Status Report
by Felix Uhl 06 Nov '14

06 Nov '14

Gordon Woodhull wrote: > We did update the formal review process and related pages to > invite people to use the Incubator to garner feedback before their library > is ready for a formal review. [*] That’s how I found out about it, so I would say the submission to the incubator is at least encouraged by Considering that, it seems a bit weird that the incubator has so little activity. > I don't think Robert ever intended the Incubator to replace the formal review or the role of the Wizards. > Instead, IMO it is better thought of as a replacement for the unscheduled > part of the review schedule (aka the Queue), and a better way to verify > the basic requirements for submitting a library. And reviews can be > submitted and responded to before the formal review, > without getting buried in the mailing list. That’s how I understood it, but from my - admittedly sparse - experience, the mailing list is an excellent place for feedback, because it is guaranteed that quite a few people will actually get the message. When I have my library ready for submission to the incubator, how is anyone going to notice it? Are enough people subscribed to the feeds that a library gets more attention than in the mailing list, or at least attention from different groups of people? It seems like the most fundamental element of the incubator is a dedicated community that is willing to participate, to test and review. And it is clearly missing exactly that. --- Felix Uhl

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Boost on Google+
by Vladimir Prus 06 Nov '14

06 Nov '14

Hi, I've created a Google+ community for Boost, and everybody is welcome to join here: https://plus.google.com/communities/106814259809358442744 I don't have any great plan here, but a lot of tech people are active on G+, so why not? -- Vladimir Prus CodeSourcery / Mentor Embedded http://vladimirprus.com

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Boost.Build 2014.10
by Vladimir Prus 05 Nov '14

05 Nov '14

New standalone release of Boost.Build is now available from: http://boost.org/build This one is effectively the same as what is bundled in Boost C++ Libraries 1.57 release. It has been a while since previous standalone release, and I know a few people were using nightly builds to conveniently get recent fixes, which is not a perfect arrangement. Turned out that github release system is fairly easy to use, so I should be able to push releases more often in future. Thanks, -- Vladimir Prus CodeSourcery / Mentor Embedded http://vladimirprus.com

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Master open?
by Joaquin M Lopez Munoz 05 Nov '14

05 Nov '14

Hi, Is master open again for commits targeted at Boost 1.58? Thank you, Joaquín M López Muñoz Telefónica

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Re: [boost] Is there interest in a library for string-convertible enums?
by Felix Uhl 05 Nov '14

05 Nov '14

Gavin Lambert wrote: > Features that I would expect of such a library: > - support for arbitrary non-contiguous values. > - enum value to string. > - string to enum value. That's done already. > - list of all valid values, either as strings or values. > - can indicate whether a given value (string or enum) is a member of > the enumeration. Easy, will do. > - can round-trip (enum -> string -> enum) values that are not members > of the enumeration; of course (string -> enum -> string) is not feasible > for non-members. What would a conversion from an enum that is not a member to a string look like? Should it just be converted to the string representation of the underlying type like “7”? Or something like “MyEnum::7”? Or would the string representation solve a term with bitwise OR like so: “one|two|four”? The latter would be very interesting for bitwise flag enums. > - can specify a custom string value that the enum value generates (not > just the BOOST_PP_STRINGIZE). Yeah I will implement that. Not sure why one would want it, it does nothing but induce confusion in my eyes, but I’m not the one to tell you what to do. > Features that would be nice, but not necessarily expected: > - enum to string and back for "bitwise flag" style enums (eg. CSV names). Not sure what you mean by that, because the regular string conversions work for those just as fine. Do you mean what I wrote above with the OR connected values in a string representation? > - some mapping to std::bitset or similar. That would be interesting! I’ve added it to the feature list, but it will probably take some time . > - can specify multiple string values that map to the same enum value. Hm. I’m not sure if I’d want that, or how that could even be implemented. If somebody wanted non-casesensitive behaviour, it would be better to use a std::string with custom char_traits, and that’s something I’ll definitely offer. > - can specify different conversion tables for the same enum type (for > use in different contexts, eg. serialisation vs. user output). I thought about that, too. I already give the option to choose between std::maps and a linear search for lookups, but I would really like to give the client more options. Those were good suggestions, thank you very much! You’ve given me quite some things to work on, but now I’ve got a pretty decent feature list. --- Felix Uhl Von: Gavin Lambert Gesendet: ‎Mittwoch‎, ‎29‎. ‎Oktober‎ ‎2014 ‎00‎:‎57 An: boost(a)lists.boost.org On 29/10/2014 00:09, Felix Uhl wrote: > So far, the only way to convert an enumeration value to a string is > a lot of boilerplate code consisting of switch case statements for > every single possible value of the enum. Not the only way. The method I use is to create a lookup table via a little macro magic. Granted that I'm then doing a linear scan through the table (whereas a switch statement could be more efficient, or knowledge that the enum is contiguous and could therefore do an index lookup), but having a table allows for other useful queries, and I wanted something that could be defined statically. As a side-benefit (that undoubtedly will horrify some people), the way the code was implemented also allows it to act as a string-to-member-pointer lookup table, which can be quite handy for typed property bags and the like with a string lookup key. > What features would you want from such a library? Features that I would expect of such a library: - support for arbitrary non-contiguous values. - enum value to string. - string to enum value. - list of all valid values, either as strings or values. - can indicate whether a given value (string or enum) is a member of the enumeration. - can round-trip (enum -> string -> enum) values that are not members of the enumeration; of course (string -> enum -> string) is not feasible for non-members. - can specify a custom string value that the enum value generates (not just the BOOST_PP_STRINGIZE). Features that would be nice, but not necessarily expected: - enum to string and back for "bitwise flag" style enums (eg. CSV names). - some mapping to std::bitset or similar. - can specify multiple string values that map to the same enum value. - can specify different conversion tables for the same enum type (for use in different contexts, eg. serialisation vs. user output). _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Fit: C++ function utility library
by pfultz2 05 Nov '14

05 Nov '14

Hi, I developed a library called Fit, that provides a lot of utilites for dealing with function objects, here: https://github.com/pfultz2/Fit First, it provides a mechanism to construct function objects at compile time using lambdas, for example: const constexpr auto sum = FIT_STATIC_LAMBDA(auto x, auto y) { return x + y; }; Secondly, it provides lots of adaptors to provide "enhancements" to the function. For example, we could make the sum function pipable: const constexpr auto sum = pipable(FIT_STATIC_LAMBDA(auto x, auto y) { return x + y; }); Then call it like this: auto three = 1 | sum(2); Or we could make it an infix operator: const constexpr auto sum = infix(FIT_STATIC_LAMBDA(auto x, auto y) { return x + y; }); And then use it like this: auto three = 1 <sum> 2; Also, it provides the basic partial application and function composition: auto add_1 = partial(sum)(1); auto add_2 = compose(add_1, add_1); auto four = add_2(1); Now, the greatest benifit is being to do better overloading and even recursive functions using lambdas. So, for example, if we wanted to write a more sophisticated `print` function that iterated over ranges and fusion sequences recursively, and printed it all out, we can write this using the Fit library: // Some helpers for template constraints #define REQUIRES(...) typename std::enable_if<(decltype(__VA_ARGS__)()), int>::type = 0 template<template<class...> class Trait, class... Ts> constexpr auto trait(Ts&&...) { return std::integral_constant<bool, Trait<std::remove_reference_t<Ts>...>::value>(); } const constexpr auto print = fix(conditional( // Overload for strings FIT_STATIC_LAMBDA(auto, const std::string& x) { std::cout << x << std::endl; }, // Overload for fusion sequences FIT_STATIC_LAMBDA(auto self, const auto& seq, REQUIRES(trait<boost::fusion::traits::is_sequence>(seq))) { boost::fusion::for_each(seq, self); }, // Overload for ranges FIT_STATIC_LAMBDA(auto self, const auto& range, REQUIRES(trait<boost::has_range_const_iterator>(range))) { for(const auto& x:range) self(x); }, // Overload for anything else FIT_STATIC_LAMBDA(auto, const auto& x) { std::cout << x << std::endl; } )); The documentation for it can be found here: http://pfultz2.github.io/Fit/doc/html/ Any feedback would be appreciated. Also, I don't know if there would be any interest in incorporating this into boost. Thanks, Paul -- View this message in context: http://boost.2283326.n4.nabble.com/Fit-C-function-utility-library-tp4668629… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[Spirit] Lex context and lexer states
by "Claas H. Köhler" 04 Nov '14

04 Nov '14

Hi! Reading the documentation regarding the context object passed by spirit lex I got a little confused: According to the quick ref for semantic actions, http://www.boost.org/doc/libs/1_57_0/libs/spirit/doc/html/spirit/lex/abstra… the context contains functions std::size_t get_state() const and void set_state(std::size_t state). So I presumed the state to be an object of type size_t. However, according to the reference section on lexer concepts http://www.boost.org/doc/libs/1_57_0/libs/spirit/doc/html/spirit/lex/refere… the Lexer state is specified in string form. So my question is: Do both representations exist (i.e. as string & size_t) and can be mapped to each other ? If so, how? Or do I control the desired type via a template parameter ? Are there any examples in the docs containing different lexer states, which could help me to understand the concept ? Any help would be appreciated. Regards Claas

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Code review for bug no. 5702
by ullas srinivas 04 Nov '14

04 Nov '14

Hi, I have fixed bug no. 5702 Bug # 5702 : Filename isreturned within quotes instead without Description : In the reference (http://www.boost.org/doc/libs/1_47_0/libs/filesystem/v3/doc/reference.html#…) it issaid that for example the filename returned by filename() will be without thequotes: std::cout <<path("/foo/bar.txt").filename(); //outputs "bar.txt" (without the quotes) But actually I'm getting anoutput with the filename enclosed in quotes like: "bar.txt" I'm using Windows Vista. Root Cause : Thefilename within quotes are due to printing of os << delim ; statement in template <class Char, classTraits, class Alloc> std::basic_ostream<Char,Traits>& basic_string_inserter_imp(std::basic_ostream<Char, Traits>&os, std::basic_string<Char, Traits, Alloc> const& string, Char escape, Char delim) of boost\io\detail\quoted_manip.hpp Fix : I have commented/removed os << delim; statementin template <class Char, classTraits, class Alloc> std::basic_ostream<Char,Traits>& basic_string_inserter_imp(std::basic_ostream<Char, Traits>&os, std::basic_string<Char, Traits,Alloc> const & string, Char escape, Chardelim) of boost\io\detail\quoted_manip.hpp I kindly request you to please find the patch file attached and review the bug. Regards Ullas

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[ANN] "The Boost C++ Libraries", 2nd edition available
by Boris Schäling 03 Nov '14

03 Nov '14

Just a quick announcement: The 2nd edition of my book "The Boost C++ Libraries" is available. - It introduces 72 Boost libraries. - It contains more than 430 examples. - The print version has about 570 pages. - There is also a Kindle, Epub and PDF version. - It's even online: <http://theboostcpplibraries.com/> A special "thank you" goes to Niall who handled this year's Google Summer of Code program so smoothly that I as a backup admin didn't need to do anything - and had enough time to work on the book. :) Boris

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Boost 1.57.0 has been released
by Marshall Clow 03 Nov '14

03 Nov '14

Release 1.57.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains no new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see http://www.boost.org/users/news/version_1.57.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.57.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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[gci2014] Calling for Google Code In 2014 tasks and mentors
by Niall Douglas 03 Nov '14

03 Nov '14

Dear Boost, Google Code In 2014 is nearly upon us, and we need bite sized tasks and mentors! Google Code In lasts between December and mid-January and is for 13 to 17 year olds to get involved with open source projects. Tasks need to be very short, maybe only three hours or so, but correspondingly the effort required to mentor/check these is very low. If you maintain a Boost library and could do with help in fixing up any of those items you keep putting off like replicating bug reports, fixing documentation errors, or configuring Continuous Integration, now is the time! More information is on the GCI ideas page at: https://svn.boost.org/trac/boost/wiki/gci2014 ... where you can add more tasks and also sign yourself up as a mentor. We need this page ready by Saturday 8th November, so please try to get it done before then. Thanks in advance! Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Re: [boost] [ANN] "The Boost C++ Libraries", 2nd edition available
by Brian Wood 01 Nov '14

01 Nov '14

On Fri, 31 Oct 2014 12:14:33 +0100, Thorsten Ottosen <tottosen(a)dezide.com> wrote: > I'm very happy to see a small chapter on ptr_container. > It's good that you compare it with container<unique_ptr<T>>. > It looks like poly_collection is left out: http://bannalia.blogspot.com.es/2014/05/fast-polymorphic-collections.html There was discussion of this container on this list back in August. > Comment 1: I would prefer examples with unique_ptr to use make_unique. > I've compared these two lines: auto req=::std::unique_ptr<cmw_request>(::new cmw_request(localbuf)); auto req=::std::make_unique<cmw_request>(localbuf); On clang 3.3, the make_unique version increases the size of an executable's text segment by 112 bytes. I think I've tried it on a newer compiler and found similar results. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[1.57.0] Release candidates available
by Marshall Clow 01 Nov '14

01 Nov '14

[ Please disregard previous message; apparently I am brain-dead this morning. The uploaded files are correct, though. ] Release candidate files for 1.57.0 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (./boost_1_57_0_rc1.7z) = 17c98dd78d6180f553fbefe5a0f57d12 MD5 (./boost_1_57_0_rc1.tar.bz2) = 1be49befbdd9a5ce9def2983ba3e7b76 MD5 (./boost_1_57_0_rc1.tar.gz) = 25f9a8ac28beeb5ab84aa98510305299 MD5 (./boost_1_57_0_rc1.zip) = 5e040e578e3f0ba879da04a1e0cd55ff Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_57_0.html

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