September 2016 - Boost - lists.preview.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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Re: [boost] Boost CRC maintainer (Daryle Walker) missing in action?
by Olaf van der Spek 19 Jun '17

19 Jun '17

Hi Daryle, Any luck on your new setup? Gr, Olaf On Mon, Nov 28, 2011 at 1:11 AM, Daryle Walker <darylew(a)gmail.com> wrote: > I can look at it once I've finished my new setup. > > I had to reset my computer after a partial crash years ago. I never > got around to recreating my programming setup. My computer had been > at its maximum Operating System level back then, which is now 3 > versions behind. For the past few months, I've had my sister's old > laptop, with Windows Vista, and am trying to add a programming setup > to it now. > > > On Tue, Nov 22, 2011 at 7:18 AM, Beman Dawes <bdawes(a)acm.org> wrote: >> Hi Daryle, >> >> This guy has volunteered to take over maintenance of Boost CRC. Should >> we take him up on his offer? > >> ---------- Forwarded message ---------- >> From: >> Date: Wed, Nov 2, 2011 at 7:51 AM >> Subject: [boost] Boost CRC maintainer (Daryle Walker) missing in action? >> To: boost(a)lists.boost.org >> >> >> Hi, >> >> It looks like the Boost CRC maintainer (Daryle Walker) is missing in action? >> >> No response to tickets from the past 3 years. What's the procedure in this case? >> >> https://svn.boost.org/trac/boost/ticket/2492 >> https://svn.boost.org/trac/boost/query?component=crc&col=id&col=summary&col… > > -- > Daryle Walker > Mac, Internet, and Video Game Junkie > darylew AT gmail DOT com -- Olaf

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[beast] Request for Discussion
by Vinnie Falco 12 Jun '17

12 Jun '17

Beast provides low level HTTP and WebSocket interfaces built on Boost.Asio, the project is here: https://github.com/vinniefalco/Beast The plan is to solicit feedback from the Boost community before submitting a request for a formal review. First a brief update: I have attended CppCon 2016 and provided a 15 minute Lightning Talk on the library. There should be a video up at some point with all the talks, including mine. I spread the word about Beast and discovered that there are several folks in the wild already using the library and happy with it. There are also a couple of commercial products that are using it. One point brought up during the conference is that Beast does not offer sufficient higher level HTTP functionality. This omission is intentional. It is my idea to offer the building blocks (serializing and deserializing HTTP/1 messages, in synchronous and asynchronous flavors, and a universal HTTP message model), upon which other developers more knowledgeable than me could build those interfaces. The higher level pubic operations requested were: 1. Perform HTTP GET or POST and receive the response. Presumably this would handle both plain and TLS connections, handle redirects, and handle HEAD requests. Not sure about traversing proxies. 2. Expose an asynchronous HTTP server class which callers can instantiate with some sort of handler that returns the HTTP response given a request. It should be possible, in a minimal number of lines, to quickly get a server up and running. The requestor informed me that this functionality did not need to provide every possible feature or handle every use case. It just needed to handle the common use-cases. For the record, I am against this higher level functionality for a number of reasons. The higher the level of functionality, the more contentious the feature becomes, and the harder it is to satisfy a quorum of reviewers. No one would dispute that we need the ability to read a complete HTTP message from a socket. But not everyone will agree that a HTTP server needs an option to allow multiple listening sockets with different level of permissions. Another problem with offering higher level functionality is that it could be less likely to be approved for standardization in the C++ standard library. For example, the attributes of ease of use and fully functional oppose each other. If the functionality offered by a hypothetical std::http::client is not sufficient, a developer would be forced to write their own with little possibility to reuse parts of the implementation from the stdlib. I doubt the committee would approve of such a thing. I know I wouldn't. Admittedly I have little experience or knowledge on what would or would not get approved. A point was raised that a low-level-only HTTP implementation in Boost has the potential to discourage new users that need to perform simple operations like HTTP GET from using Boost in the future, given that robustly handling such operations would require the developer to write a significant amount of code. I can see some validity here. On the other hand, if Boost.Asio was submitted for a formal review today, would those same points be raised? Would Asio get rejected because it doesn't offer public interfaces for doing simple tasks like requesting an object from a web server? I wonder if perhaps the Boost formal review process has become defective. For reference here is what the current API offers: Example program that performs HTTP GET, then receives and prints the response: https://github.com/vinniefalco/Beast/blob/master/examples/http_example.cpp This is a high performance asynchronous HTTP server that serves local files as static pages. It is not an official API, it is part of the examples. Users who want a server need to copy the source code and modify it to suit their needs: https://github.com/vinniefalco/Beast/blob/master/examples/http_async_server… My initial purpose for requesting this discussion is two-fold: 1. Determine the level of consensus on the issue that Beast needs to do more for HTTP than the lowest level of functionality (reading and writing messages). I'm open to hearing all arguments for and against. 2. Get feedback on what official public interfaces to higher level functionality might look like. Specifically, a client that handles GET and POST, and a generic asynchronous server. And what features those interfaces would support. For example, is traversing a proxy a necessary feature for an official client interface? The best answers would provide function signatures or class declarations using the existing Beast HTTP types. In case its not clear, I am asking stakeholders and reviewers to help design the library. I'll open a discourse on the HTTP client to illustrate the proposed style of discussion: We want to provide a HTTP client implementation that lets users perform simple tasks like fetch a resource from a remote host. Calling code should be compact, letting people get their job done without getting mired in boilerplate. Here's a possible signature with example use: response_v1<string_body> get(std::string const& url, error_code& ec); error_code ec; auto res = get("http://boost.org", ec); if(! ec) std::cout << res; else std::cerr << ec.message() << '\n'; The get function would automatically perform the name resolution, connect the socket, request the resource with uri "/", and return the result. There's a problem here though, the caller is forced to use a message with std::string as the container for the body. An obvious fix is to add a template parameter: template<class Body = string_body> response_v1<Body> get(std::string const& url, error_code& ec); Better, but what if the body is not DefaultConstructible? We can add some parameters to forward to the Body constructor: template<class Body = string_body, Args&&... args> response_v1<Body> get(std::string const& url, error_code& ec, Args&&... args); We're getting somewhere now. Most users will use the default body, while an option exists for advanced users. But the implementation of get now has a complication. If an error occurs, it still has to construct a return value. This problem is likely surmountable but lets table it and start a new line of reasoning. What if the URI indicates https, e.g. "https://boost.org"? We can hide that under the hood by using a separate code path that uses asio::ssl::stream instead of ip::tcp::socket. But how does the caller provide the root CA certificates? How does the caller provide a client certificate? We are left with a client that satisfies two thirds of users but is unusable for the remaining one third. Is this Boost worthy? Is this std-lib worthy? I think not. Lets revisit the SSL issues later and think about a new problem. What happens to the socket when the request is done? In the proposed interface, the socket is destroyed. This means you can only make one request on a connection. At this point, I think its clear that the current interface is a non-starter. Here's a better idea. Lets define a class called client and make get a member function. Now we can have state, including configurable settings with reasonable defaults. class client { public: template<class Option> void set_option(Option&&); template<class Body = string_body, Args&&... args> response_v1<Body> get(std::string const& url, error_code& ec, Args&&... args); }; client c; error_code ec; auto res = c.get("http://boost.org", ec); if(! ec) std::cout << res; else std::cerr << ec.message() << '\n'; We still have some of the original problems, but other problems are solved. The class can keep the socket around, so that a subsequent call to get with the same server will use the already-open socket. The caller can set options on the client object instance before invoking get, such as any TLS certificates. Unfortunately we have new problems. Where is the io_service? If the class creates it for you, how many threads? How do I use my existing io_service, or is that even necessary? The class interface allows the connection to be kept alive but what if now the caller wants to close it (i.e. specify "Connection: close" in the request)? And there are some problems which are applicable to any interface. How does the caller adjust the parser options, for example change the limit on the size of the body? What if the caller wants the request made using a specific HTTP version? How does this handle basic authentication? How can the caller adjust the headers in the request? etc... This is why I think that offering a HTTP client is a rabbit hole which can only lead to a rejected formal review. Or maybe I am overthinking this? I'd love to hear proposed solutions to the issues (which could be just to say "forget about those features"). Despite my objection I have started work on these features anyway. Here are the beginnings of a HTTP client: https://github.com/vinniefalco/Beast/blob/88b485df7e6216282842f40cf99cc75de… Here is some work on a generic server: https://github.com/vinniefalco/Beast/blob/server/extras/beast/http/async_se… Please reply to this thread instead of starting a new thread, and keep the subject line prefix (e.g. "Re: [boost] [beast] ...") Thank you

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[msm] [statechart] unmerged PRs
by András Kucsma 23 May '17

23 May '17

Hi Everyone, There are a couple of PRs for msm and statechart by me and others, which didn't get any attention for many months now. Can the maintainers please take a look at them? https://github.com/boostorg/msm/pulls https://github.com/boostorg/statechart/pulls Thank you, Andras

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[clang] clang-cl expansion of macros
by Edward Diener 29 Apr '17

29 Apr '17

You can get clang-cl ( clang-win ) to show its VC++ emulated expansion of macros somewhat by passing the c++ option '-fmacro-backtrace-limit=0' to the compiler. It is still blessedly difficult to see the what and the why of clang's error messages when expanding macro using clang-cl, but at least it gives you a better chance of understanding where clang's emulation of VC++ has gone wrong. I have posted bug 27380 to the llvm/clang bug tracker at https://llvm.org/bugs/show_bug.cgi?id=27380 showing the main failure in VC++ emulation which I see when testing Boost PP with clang-cl.

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[container] moving a pre-built vector into a flat_set
by Sam Kellett 12 Mar '17

12 Mar '17

a common problem i encounter is that i have two stage's w/r/t to a large collection of data: building and querying. vector is obviously the king of building. flat_set is the king of querying. so what i often tend to do is build up a very large vector, sort it then create a flat_set using the flat_set(ordered_unique_t) constructor. however this still copies the entire vector into the flat_set, right? what i would like to be able to do is move the vector straight into the flat_set, something like: std::vector<T> data; flat_set data_set1(std::move(data)) // move vector in and sort it // or: std::sort(data.begin(), data.end()); // sort vector flat_set data_set2(ordered_unique_t, std::move(data)) // and move it in is this doable (am i just being blind?) or is there plans/interest for this?

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[nowide] Library Updates
by Artyom Beilis 04 Mar '17

04 Mar '17

Hello, Disclaimer: --------------- I recently discovered that virtually all e-mails sent from Yahoo account to any mailing lists go to user's spam due to recent Yahoo's DMARC policy. So I'm sending some important stuff from GMail account that almost certainly was missed: What is Boost.Nowide: -------------------------------- Boost.Nowide is a library that make cross platform Unicode aware programming easier. The library provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. It was inspiration and inspired by http://utf8everywhere.org/ development ideas and policy. Some updates regarding Boost.Nowide ------------------------------- 1. Library moved to github and its format is converted to modular boost layout: https://github.com/artyom-beilis/nowide 2. Fixed unsupported std::ios::ate flag by boost::nowide::fstream 3. Added some C++11 interfaces to boost::nowide::fstream 4. Added integration functionality with boost::filesystem: https://github.com/artyom-beilis/nowide/blob/master/include/boost/nowide/in… Note: that the links to the source code on review schedule aren't relevant, it should be: - Code: https://github.com/artyom-beilis/nowide - Documentation: http://cppcms.com/files/nowide/html/ Also the library is still looking for review manager. Artyom Beilis P.S.: I'm sorry if you are getting this as "duplicate"

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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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Generating Boost documentation with pandoc
by Vinícius dos Santos Oliveira 18 Jan '17

18 Jan '17

Has anyone tried to generate Boost-styled documentation using pandoc? I never fully liked PDF documentation because I never actually print documentation. However, a few weeks ago I got an ebook reader and I've been fascinated by the ePUB format. I'm using it to read even the IETF's RFCs and it's very pleasant. I'm using ePUB to read files even on my usual laptop. Anyway, I was wondering how nice would be to have an ePUB file containing the whole Boost documentation. pandoc has docbook support as one of its input formats and is capable of generating great ePUB output. -- Vinícius dos Santos Oliveira https://vinipsmaker.github.io/

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[MPL] A Proposal
by Bruno Dutra 16 Nov '16

16 Nov '16

Dear Community, About a year ago today, there was a proliferation of threads [1][2][3] in this mailing list concerning the future of Boost.MPL, or even whether it had a future at all, and opinions diverged widely on the matter. Many have expressed concerns about the fact Boost.MPL was long outdated and proposed major changes to open path for modernization, while some others argued against it, fearing unexpected and disastrous side-effects could propagate throughout the rest of Boost. A few questioned if it was worth it at all to spend any further resources on Boost.MPL given the fact new alternatives were coming up, such as Boost.Hana, which departed entirely from template metaprogramming, yet some argued TMP remained a competitive alternative for type computations in C++14 as it has been demonstrated by Peter Dimov in his impressive articles [4] on modern TMP. Amidst all this, a proposal by Robert Ramey [5] caught my attention and inspired me to develop what I call Metal [6], a template metaprogramming library designed on the same core principles as Boost.MPL, but written from the very beginning to take full advantage of C++11. Metal was not designed to be a strict drop in replacement for Boost.MPL though, it was rather meant to be regarded as a modern version of Boost.MPL's original API, diverging only where it could really benefit from modern C++ and that essentially means gains of several orders of magnitude in performance** and lower memory consumption. At this point Metal is very close to where I originally intended to bring it and I think it's time I gauge interest from the community on a modest proposal I've been maturing along the past year. As a modern approach to the same task that Boost.MPL was meant to address, I don't believe Boost would benefit at all from yet another TMP library that would essentially compete with Boost.MPL and even Boost.Hana in some cases, specially as maintainers of older code that depends on Boost.MPL would have to go through major refactoring efforts in order to benefit from such an addition to Boost. I would like to propose something different instead. My proposal is to make Metal officially into a new revision of Boost.MPL's API, essentially MPL2 as the original proposal by Robert Ramey put it, merging both into one single TMP library. The idea would be to provide a thin proxy for the current Boost.MPL API which would have two backends configurable by preprocessor switches: the original implementation and a another one based on Metal. This way older code using Boost.MPL could see immediate gains on performance by selecting the newer backend on supported compilers, while at the same time legacy code maintained on older compilers could still rely on Boost.MPL's impressive ability to run virtually anywhere. On the other hand, newer projects interested on pure type computations would have the newer API entirely available to them. This proposal also overcomes the problem of dealing with the maintainability of Boost.MPL, since it provides a way for smooth transition from legacy hacks required by ancient compilers into a cleaner and easier to maintain C++11 codebase, besides avoiding any breaking changes within existing code in the process. Furthermore, should this proposal make it into Boost, I would be naturally willing to take responsibility for the maintenance of Boost.MPL, which AFAIK has been maintained by the CMT for quite some time now, often with limited resources. Comparing Metal and Boost.MPL there are a few noteworthy differences. Metafunction Classes have proven themselves entirely unnecessary and have thus been removed altogether in favour of pure Lambdas (in the Boost.MPL sense). Moreover, iterators make little sense in a functional world, so these too have been removed despite the fact they may easily be emulated in the new design. Moreover Metal develops the concept of optionals, that is, its metafunctions only have a nested ::type defined when they may be successfully computed, what may be safely tested using metal::is_just and may also be used to SFINAE out of miscomputations. Finally I'd like to point out that Metal was designed to be portable across as many compilers as possible and three of the most popular ones are continuously tested using Travis and Appveyor: Clang 3.5+, GCC 4.8+ and MSVC 14 (2015). I hope this is a reasonable proposal and I look forward into your opinions about it. ** Even though I haven't published any benchmarks yet, an example follows just to back my claims regarding performance (just tested on my personal laptop running linux): //Generate a list containing 10 thousand instances of std::integral_constant, from 0 to 9999 using l = metal::enumerate_t<metal::integer<10000>>; // GCC 5.3 ~0.4 s // Clang 3.7 ~0.5 s //Transform a list containing 5 thousand numbers by squaring each element using l1 = metal::enumerate_t<metal::number<long long, 5000>>; using l2 = metal::transform_t<metal::pow<metal::_1, metal::integer<2>>, l1>; // GCC 5.3 ~5.6 s // Clang 3.7 ~3.0 s [1]: http://thread.gmane.org/gmane.comp.lib.boost.devel/257680 [2]: http://thread.gmane.org/gmane.comp.lib.boost.devel/257983 [3]: http://thread.gmane.org/gmane.comp.lib.boost.devel/258843 [4]: http://pdimov.com/cpp2/simple_cxx11_metaprogramming.html [5]: http://rrsd.com/blincubator.com/bi_suggestion/mpl-lite-or-mpl2/ [6]: http://brunocodutra.github.io/metal/ Regards, Bruno Dutra

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[boost.process] Review
by Klemens Morgenstern 27 Oct '16

27 Oct '16

Boost.Process 0.6, as can be found here (https://github.com/klemens-morgenstern/boost-process) will be in review from October 27 to November 5. The review manager will be Antony Polukhin. Doc (http://klemens-morgenstern.github.io/process/) I really hope this library gets through the review, since boost (or C++ for that matter) really needs a process library. I would be really happy, if some of you could take the time to look into it - if you find any major issues, they might be addressed, before the actualy review. That would then increase the probability of the library getting accepted.

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Review request: Beast
by Vinnie Falco 04 Oct '16

04 Oct '16

Can Beast please be added to the review queue? Michael Caisse has volunteered to act as the review manager. Beast provides C++11, header-only implementations of the HTTP and WebSocket protocols using Boost.Asio and presenting a consistent, modern synchronous and asynchronous interface style. Beast project repository https://github.com/vinniefalco/Beast HTML documentation http://vinniefalco.github.io/beast Boost incubator link: http://blincubator.com/bi_library/beast-2/?gform_post_id=1579 Thanks!

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Extending Boost.Python with NumPy support
by Stefan Seefeld 04 Oct '16

04 Oct '16

Hello, I'm presently working on a few improvements to the Boost.Python module. As part of this I'm refactoring the numeric API to actually support NumPy. There has been quite a lot of effort we put into this in the past (notably a GSoC project I mentored a few years ago), but we never managed to include this into the Boost master branch, so it's never been formally released. As I'm now getting ready to polish this work off, I wonder whether any of this would require a formal submission as a new Boost library, or whether it can just be done under the Boost.Python umbrella ? I reckon this is somewhat of a gray area, so I'd like to clarify whether there are concrete rules for what changes / additions require a formal review process. Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

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How to build Boost with VS15
by Olaf van der Spek 04 Oct '16

04 Oct '16

Hi, How does one build Boost (1.62) with VS15 (Preview 4)? I know it's not officially supported.. C:\VC\boost>bootstrap.bat Building Boost.Build engine 'cl' is not recognized as an internal or external command, operable program or batch file. Failed to build Boost.Build engine. Please consult bootstrap.log for further diagnostics. -- Olaf

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CMake Modularization
by Philip Woods 03 Oct '16

03 Oct '16

CMake is a widely used build system and has become for many the de facto standard. Boost is a widely used collection of modules and has become for many part of the de facto standard. However, the two do not play very well together. I know there is another port of boost to CMake, but it has lain dormant for years and uses an old version of boost; plus I chose to take a different route. The old project attempted to completely replace Boost.Build with CMake. My example port simply allows people to more easily use boost modules in their projects. I created an example project https://github.com/Elzair/cmake-boost-filesystem-test to demonstrate my ideas. I added CMake build support to the minimum number of modules needed to support this demo: https://github.com/Elzair/assert https://github.com/Elzair/config https://github.com/Elzair/core https://github.com/Elzair/filesystem/tree/master and https://github.com/Elzair/system I even added CMake build support to the header only boost libraries. I did this for two reasons. First, I did not want users to have to fool with CMake's find_package(). Second, I wanted to add helpful error messages in case a user has not included all of a module's dependencies (or added them in the wrong order). Would the community be interested in modular CMake support for more modules? Any comments, questions, critiques or suggestions are welcome.

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Cannot open include file: 'pyconfig.h'
by Olaf van der Spek 30 Sep '16

30 Sep '16

Hi, Boost 1.62 @ VC15, no Python installed: call "C:\Users\W7\AppData\Local\Temp\b2_msvc_default_vcvarsall_x86.cmd" >nul cl /Zm800 -nologo @"bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\import.obj.rsp" ...failed compile-c-c++ bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\import.obj... compile-c-c++ bin.v2\libs\python\build\msvc\debug\link-static\threading-multi\exec.obj exec.cpp C:\VC\boost\boost/python/detail/wrap_python.hpp(50): fatal error C1083: Cannot open include file: 'pyconfig.h': No such file or directory Should it be trying to build Python stuff? -- Olaf

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[release] Boost 1.62.0 release available
by Rene Rivera 30 Sep '16

30 Sep '16

Release 1.62.0 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 two new libraries and numerous enhancements and bug fixes for existing libraries. New Libraries * Fiber: Framework for userland-threads/fibers, from Oliver Kowalke. * QVM: Boost QVM is a generic library for working with quaternions, vectors and matrices of static size with the emphasis on 2, 3 and 4-dimensional operations needed in graphics, video games and simulation applications, from Emil Dotchevski. For details, including download links, see http://www.boost.org/users/ news/version_1.62.0 You can also download directly from SourceForge: http://sourceforge.net/ projects/boost/files/boost/1.62.0/ The SHA256 checksums are as follows: b91c2cda8bee73ea613130e19e72c9589e9ef0357c4c5cc5f7523de82cce11f7 boost_1_62_0.7z 36c96b0f6155c98404091d8ceb48319a28279ca0333fba1ad8611eb90afb2ca0 boost_1_62_0.tar.bz2 440a59f8bc4023dbe6285c9998b0f7fa288468b889746b1ef00e8b36c559dce1 boost_1_62_0.tar.gz 084b2e0638bbe0975a9e43e21bc9ceae33ef11377aecab3268a57cf41e405d4e boost_1_62_0.zip Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.62.0/ 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

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[release] Master open for changes.
by Rene Rivera 30 Sep '16

30 Sep '16

FYI.. Master branches are now open for changes for the next release. Note that because of the late 1.62.0 release the window for the next release is shorter than usual. And there is now less than a month before master closes again for new libraries. Please consult the calendar for further dates. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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[asio] inefficiency in the polling
by Tatsuyuki Ishi 29 Sep '16

29 Sep '16

The current run/poll_one does polling regardless if there's task in the queue. If there's task in the queue, polling is just a waste of system call, since there's already a job to do. Also, my common use case is "wait and consume all work", which is not covered efficiently by current design. (run_one+poll takes two system calls) Side note: on Windows asio performs even worse, it only retrieve one event per syscall... Not sure if it's intended. Friendly note: please use "Reply to All" when replying to me.

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Population count procedure in dynamic_set
by Wojciech Muła 28 Sep '16

28 Sep '16

Hello! The library dynamic_bitset contains a slow population count procedure: https://github.com/boostorg/dynamic_bitset/blob/340822f979371973fe4a8436362… There are several better, faster and (more or less) portable algorithms. Daniel Lemire, Nathan Kurz and I work on a library which provides fastest possible implementations for CPU having AVX2 instruction set, you can check out its current state: https://github.com/CountOnes/hamming_weight. I also did an extensive comparison of different algorithms on different machines: https://github.com/WojciechMula/sse-popcount, one example https://github.com/WojciechMula/sse-popcount/blob/master/results/skylake/sk… As I mentioned these algorithms are different, the fastest use SIMD instructions, other depends on a CPU instruction. However, some approaches are portable, machine-independent, like this https://github.com/WojciechMula/sse-popcount/blob/master/popcnt-bit-paralle… It's possible to provide better solution at small cost, a lot of work has already been done. Would you be interested in including such boosted procedures as part of dynamic_bitset (or a new library)? Popcount itself is used in number of fields: I've found it in DNA matching (Jaccard index), computer vision, databases, and Daniel recently reported application in machine learning. best regards Wojciech

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[container] Trie data structure
by Зайцев Александр 28 Sep '16

28 Sep '16

Hi! My implementation of Aho-Corasick uses my own implementation of trie data structure. But i want something to use from Boost. Is there trie in Boost? If not, can I start work on trie for Boost? -- Best regards, Alexander Zaitsev

6 9

Re: [boost] [Boost-users] [release] Boost 1.62.0 Release Candidate 1
by Marshall Clow 28 Sep '16

28 Sep '16

On Tue, Sep 27, 2016 at 7:14 PM, Edward Diener <eldiener(a)tropicsoft.com> wrote: > On 9/27/2016 9:24 PM, Marshall Clow wrote: > >> >> >> On Mon, Sep 26, 2016 at 5:52 PM, Marshall Clow <mclow.lists(a)gmail.com >> <mailto:mclow.lists@gmail.com>> wrote: >> >> On Mon, Sep 26, 2016 at 7:36 AM, Rene Rivera <grafikrobot(a)gmail.com >> <mailto:grafikrobot@gmail.com>> wrote: >> >> The release candidates for the 1.62.0 release are now available >> at: >> >> >> [snip] >> >> >> >> Now to run some tests.... >> >> -- Marshall >> >> >> The test "vmd/test/test_doc_modifiers_return_type.cpp" hangs clang. >> Reported as https://llvm.org/bugs/show_bug.cgi?id=30546 >> > > Evidently clang runs out of memory. Note that with VC++ and gcc the test > passes. > > I don't know why clang would run out ot memory while VC++ and gcc do not > but I have not queried the clang mailing list further about it. An educated > guess is that clang calculates some fixed size for the preprocessor and > when macro expansions cause that fixed size to overrun you get an out of > memory condition. I can hardly believe that the preprocessor is really > running out of virtual memory, no matter how complicated the preprocessor > code gets in VMD. > > When I was discussing the problem with Richard, he opined that that might be a problem, if the preprocessed source exceeded 1 GB in size - which it doesn't. (GCC expands this test to about 700K) So I suspect it is "just a bug" -- Marshall

1 0

[release] Boost 1.62.0 Release Candidate 1
by Rene Rivera 28 Sep '16

28 Sep '16

The release candidates for the 1.62.0 release are now available at: https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… https://sourceforge.net/projects/boost/files/boost/1.62.0.rc.1/boost_1_62_0… The SHA256 checksums are as follows: b91c2cda8bee73ea613130e19e72c9589e9ef0357c4c5cc5f7523de82cce11f7 boost_1_62_0_rc1.7z 36c96b0f6155c98404091d8ceb48319a28279ca0333fba1ad8611eb90afb2ca0 boost_1_62_0_rc1.tar.bz2 440a59f8bc4023dbe6285c9998b0f7fa288468b889746b1ef00e8b36c559dce1 boost_1_62_0_rc1.tar.gz 084b2e0638bbe0975a9e43e21bc9ceae33ef11377aecab3268a57cf41e405d4e boost_1_62_0_rc1.zip 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. Thanks, the release managers. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

6 9

[dll] Problem building documentation on Windows
by Vinnie Falco 27 Sep '16

27 Sep '16

I am trying to build the Boost documentation on Windows and I am encountering this error bash-4.3$ pwd /d/lib/boost_1_62_0/libs/dll/doc bash-4.3$ bjam Jamfile.v2:66: in modules.load *** argument error * rule doxygen ( target : sources + : requirements * : default-build * : usage-requirements * ) * called with: ( autodoc_shared_library_core : : <doxygen:param>HIDE_UNDOC_MEMBERS=YES <doxygen:param>HIDE_UNDOC_CLASSES=YES <doxygen:param>HIDE_SCOPE_NAMES=YES <doxygen:param>EXTRACT_ALL=NO <doxygen:param>EXTRACT_PRIVATE=NO <doxygen:param>BUILTIN_STL_SUPPORT=YES <doxygen:param>ENABLE_PREPROCESSING=YES <doxygen:param>MACRO_EXPANSION=YES <doxygen:param>ALIASES= \ "forcedlink{1}=\xmlonly<link linkend='boost.dll.\1'>boost::dll::\1</link>\endxmlonly" \ "forcedmacrolink{1}=\xmlonly<link linkend='\1'>\1</link>\endxmlonly" <doxygen:param>PREDEFINED= \ "BOOST_RV_REF(T)=T&&" \ "BOOST_RV_REF(shared_library)=shared_library&&" \ "BOOST_COPY_ASSIGN_REF(shared_library)=const shared_library&" \ "BOOST_MOVABLE_BUT_NOT_COPYABLE(shared_library)= \ shared_library(const shared_library&) = delete; \ shared_library& operator=(const shared_library&) = delete; " \ "BOOST_DLL_IMPORT_RESULT_TYPE=result_type" \ "BOOST_DLL_MANGLED_IMPORT_RESULT_TYPE=result_type" \ "BOOST_EXPLICIT_OPERATOR_BOOL()=explicit operator bool() const noexcept;" \ "BOOST_DLL_DOXYGEN" <xsl:param>boost.doxygen.reftitle=Shared Library Reference ) * missing argument sources D:/lib/boost_1_62_0/tools/build/src/tools\doxygen.jam:622:see definition of rule 'doxygen' being called D:/lib/boost_1_62_0/tools/build/src/build\project.jam:325: in load-jamfile D:/lib/boost_1_62_0/tools/build/src/build\project.jam:64: in load D:/lib/boost_1_62_0/tools/build/src/build\project.jam:145: in project.find D:/lib/boost_1_62_0/tools/build/src\build-system.jam:535: in load D:\lib\boost_1_62_0\tools\build\src/kernel\modules.jam:295: in import D:\lib\boost_1_62_0\tools\build\src/kernel/bootstrap.jam:139: in boost-build D:\lib\boost_1_62_0\boost-build.jam:17: in module scope I get the same error when I try to build the full documentation from boost_1_62_0/doc/ My doxygen is at version 1.8.12 -- Follow me on Github: https://github.com/vinniefalco

2 5

[fiber] design fault with multithreading
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

The current design doesn't allow a work-stealing algorithm to distribute work perfectly. Unfortunately, the use of sleep queue and remote ready queue made it insufficient for schedulers like shared_work. Instead here, I'd like to propose it as non-pure virtual function in the algorithm class. This allows schedulers to override the queues, and enables the use of underlying implementation's timer manager, which is included in Asio. Friendly notice: please use "Reply All" when replying to me.

1 0

Boost should not be saying "_FPOSOFF"
by Billy O'Neal (VC LIBS) 27 Sep '16

27 Sep '16

Hello, Boost folks. :) I tried to remove this undocumented internal macro from our STL because we used it in only one place, but this broke Boost: #define _FPOSOFF(fp) ((long long)(fp)) ...patience... ...found 722 targets... ...updating 18 targets... common.mkdir build\boost\bin.v2\libs common.mkdir build\boost\bin.v2\libs\iostreams common.mkdir build\boost\bin.v2\libs\iostreams\build common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99 common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj mapped_file.cpp d:\src\vc\wcfb01\qa\vc\FE\3rdpartycomp\boost_1_60_0\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-gd-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\debug\link-static\threading-multi>libboost_iostreams-vc-mt-gd-1_60.lib... common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static common.mkdir build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\file_descriptor.cpp(265): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data libs\iostreams\src\file_descriptor.cpp(289): warning C4244: 'argument': conversion from 'std::streamsize' to 'DWORD', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\file_descriptor.obj... compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj mapped_file.cpp .\boost/iostreams/positioning.hpp(107): error C3861: '_FPOSOFF': identifier not found libs\iostreams\src\mapped_file.cpp(59): warning C4244: 'return': conversion from 'const boost::iostreams::stream_offset' to '::size_t', possible loss of data libs\iostreams\src\mapped_file.cpp(325): warning C4244: 'argument': conversion from 'boost::iostreams::stream_offset' to 'SIZE_T', possible loss of data cl /Zm800 -nologo @"build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj.rsp" ...failed compile-c-c++ build\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi\mapped_file.obj... ...skipped <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>file_descriptor.obj... ...skipped <pstage\lib>libboost_iostreams-vc-mt-1_60.lib for lack of <pbuild\boost\bin.v2\libs\iostreams\build\msvc-99\release\link-static\threading-multi>libboost_iostreams-vc-mt-1_60.lib... ...failed updating 4 targets... ...skipped 4 targets... ...updated 10 targets... failed Billy3

8 18

[iterator] Is there any interest in Null Iterator Adaptor ?
by Rahman Salim Zengin 27 Sep '16

27 Sep '16

Hi! It would be pleasure for me to hear about your precious thoughts. https://github.com/rszengin/null_iterator Best regards.

3 5

Re: [boost] [fiber] Suggestions regarding asio
by Tatsuyuki Ishi 27 Sep '16

27 Sep '16

It would be better if you used "Reply to All", since I disabled the delivery from the list. > When considering using multiple threads with an io_service passed to a custom Boost.Fiber scheduler, I keep bumping into the problem that a given fiber scheduler instance must always run on its original thread -- but I know of no way to give an Asio handler "thread affinity." How do we get processor cycles to the scheduler on the thread whose fibers it is managing? Since we only poll on one master thread, we can easily get affinity. Maybe pseudocode is easier: * We have two class, one for main polling, others waiting for job. * The first one, polls from asio using the same way as the example (poll, or run_one). while(true) { if(!run_one()) stop_other_threads(); // No more work in asio, give up waiting poll(); // flush the queue // Now we should have some fibers in the queue. yield(); // continue execution } * Other threads, uses condvar to wait on the ready queue. awakened(){queue.push_back(f); cv.notify_[one,all](); iosvc.post([]{});} pick_next(){while(!jobs_available){cv.wait();} return job;}

5 7

Code complexity
by Vard Antinyan 27 Sep '16

27 Sep '16

Dear Boost developers, We have undertaken a task to assess code complexity triggers and generate recommendations for developing simple and understandable code. Our intension is to share the results with you, developers, so everyone can learn the triggers behind complex software. We need your help for rigorous results. My request to you is - if you get 5-10 min. time, would you please consider to answer the questions of this survey on code complexity? https://goo.gl/forms/h9WXZ8VSEw7BUyHg1 You are welcome to learn preliminary results through this link: https://www.facebook.com/SoftwareCodeQuality/photos/?tab=album&album_id=163… The results will be shared in a public webpage and everyone possible will be invited to learn and discuss them. Your knowledge and experience is vital for achieving substantial and generalizable results, and your effort is much appreciated! Sincerely Vard Antinyan PhD candidate in University of Gothenburg, Sweden Tel: 0046317725707

2 1

(Boost) Synapse update
by Emil Dotchevski 27 Sep '16

27 Sep '16

(Synapse is not part of Boost. I appreciate feedback as well as looking for someone willing to volunteer as review manager when Synapse is submitted for formal review.) Synapse is a signal-programming library similar to the Qt signal/slot system and Boost Signals 2. The difference is that Synapse is non-intrusive: any object of any static type whatsoever can serve as an emitter. I've just updated Synapse with support for interthread communication. It is available on github: http://zajo.github.io/boost-synapse/index.html. Thanks, Emil

3 5

Need help with errors while building boost for clang on android NDK
by Robert Dailey 26 Sep '16

26 Sep '16

I'm using NDK r11 and I'm setting up project-config.jam to build boost using clang + llvm STL. I'm running into a few errors that I do not know how to solve. I will post my config file at the bottom. First problem is that boost does not know where to find tools 'ar' and 'ranlib': clang-linux.archive bin.v2\libs\container\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\libboost_container-clang-mt-s-1_61.a '"ar"' is not recognized as an internal or external command, operable program or batch file. '"ranlib"' is not recognized as an internal or external command, operable program or batch file. How can I explicitly specify the NDK path to these executables? Second problem is related to some assembler stuff, I think. I get these errors while compiling boost thread: clang-linux.compile.asm bin.v2\libs\context\build\clang-linux-android\release\link-static\runtime-link-static\target-os-linux\threading-multi\asm\make_i386_ms_pe_gas.o libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:1: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:22: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:36: error: expected identifier in directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:30:40: error: unknown directive .def _make_fcontext; .scl 2; .type 32; .endef ^ libs\\context\\src\\asm\\make_i386_ms_pe_gas.asm:136:1: error: unknown directive .def __exit; .scl 2; .type 32; .endef ^ How can I solve this? I have no idea at this point. I'm invoking the build using: b2 --without-python threading=multi link=static runtime-link=static toolset=gcc-android target-os=linux threadapi=pthread --stagedir=android stage And my project-config.jam looks like: import option ; option.set keep-going : false ; androidNDKRoot = E:/android/ndk ; androidAbiVer = 4.9 ; androidPlatform = windows-x86_64 ; using clang : android : $(androidNDKRoot)/toolchains/llvm/prebuilt/$(androidPlatform)/bin/clang++ : <compileflags>--sysroot=$(androidNDKRoot)/platforms/android-15/arch-arm <compileflags>-Os <compileflags>-fno-strict-aliasing <compileflags>-O2 <compileflags>-DNDEBUG <compileflags>-g <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++abi/libcxxabi/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libcxx/include <compileflags>-I$(androidNDKRoot)/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a <compileflags>-I$(androidNDKRoot)/sources/android/support/include <compileflags>-DANDROID <compileflags>-D__ANDROID__ <compileflags>-D__arm__ <compileflags>-D_REENTRANT ;

1 1

[Math/Special Functions] Is there any interest in the Lambert W function?
by Balázs Cziráki 26 Sep '16

26 Sep '16

Greetings! I'm working on a C++ implementation of the Lambert W (a.k.a. product logarithm or Omega function) and I wanted to ask the Boost developer community if there is interest in adding it to the library. The current version can be found on GitHub: https://github.com/CzB404/lambert_w/ I've successfully tested it with Cygwin GCC v5.4, v6.2 and with MinGW GCC that is supplied with Code::Blocks, and also on Visual Studio 2015. A test on a Linux based OS (probably Ubuntu) is also going to happen. Any suggestions or constructive criticism is welcome. Best regards, Balázs Cziráki

4 5

[range] sub_range of istream_range
by Andrew Hundt 26 Sep '16

26 Sep '16

I’m trying to iterate through a file using sub_ranges of an istream_range of an ifstream. However, it seems if I construct sub ranges of various subsets of the full istream_range, try to adjust the limits with advance_begin and advance_end, and then access them I get null dereferences. Any thoughts? I can produce an example if needed. Cheers! Andrew Hundt

1 0

markable -- informal review request
by Andrzej Krzemienski 24 Sep '16

24 Sep '16

Hi Everyone, I would like to ask your opinion, suggestions, and perhaps an informal review of the 'markable' library. An alternative to boost::optional when performance really matters. It is the second incarnation of the 'compact_optional' library that I have presented last year. The main differences from the previous version: * name change: it is called 'markable' so that it is not confused with 'optional'. It uses "mark values" and mark policies" * it has the ability to mark an empty state even for the types with strong invariants, by marking a bit pattern rather than any proper value of T (an idea by Matt Calabrese) An example use case: typedef markable<mark_int<int, -1>> opt_int; opt_int oi; opt_int o2 (2); assert (!oi.has_value());assert (o2.has_value());assert (o2.value() == 2); static_assert (sizeof(opt_int) == sizeof(int), ""); The github repository: https://github.com/akrzemi1/markable And documentation therein: https://github.com/akrzemi1/markable/tree/master/documentation Any comments, suggestions or critique are most welcome. Regards, &rzej;

4 8

[fiber] Suggestions regarding asio
by Tatsuyuki Ishi 22 Sep '16

22 Sep '16

The current example seems non-flexible and very hacky. 1. The timer handler has no problem, since it's expected to be called from any thread. (Description in "Deeper Dive into asio" is meaningless) 2. Possible alternatives: * A post(empty lambda) is a little bit waste but solves the threading problem. It wakes up one thread by doing interrupt of epoll etc. Maybe adding a interrupt method to asio codebase could be more efficient. * One thread doing event polling and the other doing condvar is enough. Since we're not expecting a slow handler (most times, it just make a fiber ready), this should be sufficient. Correct me if I'm wrong.

2 1

[interprocess] Improved shared_memory lifetime using file locks?
by Sebastian Theophil 21 Sep '16

21 Sep '16

Hi, coming from Windows, the filesystem persistence of basic_managed_shared_memory is giving us headaches. When we have N processes accessing the same shared memory, and one of them crashes, the other N-1 are in an undefined state. That’s the same on Windows and POSIX platforms and is ok for us. On Windows, the problem resolves itself when the other N-1 processes are all closed and then restarted, because Windows deletes the shared memory automatically. On POSIX systems, I think we can use file locks to make sure that the shared memory is reinitialized by the first process to access it. I’d appreciate any feedback, especially if it points out the problems with this approach: - basic_managed_shared_memory(boost::interprocess::open_or_create, …) opens the backing file with flags O_CREAT | O_EXLOCK | O_NONBLOCK - if that succeeds: - we are the first - (re-) initialize shared memory - also a good time to unlink/open the named POSIX semaphore that’s hanging around in an invalid state too! - degrade exclusive lock using flock(LOCK_SH) - else - open file with flag O_SHLOCK (open only, and blocking!) - when that succeeds, open shared memory Problems I can see: - Only works when (advisory) shared and exclusive locking and the degradation of one to the other is supported (at least flock not supported on Windows, e.g.) - What about other file systems? NFS? - Somebody could lock all your files. (OTOH, sb could also delete all my backing files all the time. My application would run, but not have any shared memory. Might be an advantage that my application does *not* run when the file is locked.) - What else? Is this worth implementing in boost.interprocess? I appreciate any feedback, Sebastian PS: I’ve googled previous discussions about shared memory lifetime in boost.interprocess. I don’t claim that my proposal gives the same semantics as Windows shared memory. It doesn’t and it seems impossible to achieve. I’m looking for, erm, usable semantics on POSIX systems. Clearly, everybody has to implement some lifetime tracking. It would be nice if boost.interprocess provided one or more solutions. -- Dr. Sebastian Theophil | stheophil(a)think-cell.com Senior Software Engineer We are looking for C++ Developers: https://www.think-cell.com/career think-cell Software GmbH | Chausseestr. 8/E | 10115 Berlin | Germany https://www.think-cell.com | phone +49 30 666473-10 | US phone +1 800 891 8091 Amtsgericht Berlin-Charlottenburg, HRB 180042 Directors: Dr. Markus Hannebauer, Dr. Arno Schödl

1 0

[release] 1.62.0 Master branch is closed
by Rene Rivera 21 Sep '16

21 Sep '16

The master branch is now closed for all changes, except by permission from a release manager. Thanks, The Release Team -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

1 0

[release] Boost 1.62.0. Beta 2
by Rene Rivera 20 Sep '16

20 Sep '16

The packages for 1.62.0 beta 2 are now available: <https://sourceforge.net/projects/boost/files/boost/1.62.0.beta.2/> The SHA256 checksums are as follows: 95feae3620b3e604e93f14d97195fc04a4b67063692859af8df19657d41b82d5 boost_1_62_0_b2.7z 27bc9b328ff73d7dbf80cd9d4b5f79b0878221e5d8e4b6c47444b135edc1080a boost_1_62_0_b2.tar.bz2 3939d5efa683449e87b374d7e92e3eeb6490063ddb2877919f0fad26e3a0f53e boost_1_62_0_b2.tar.gz cff9ab5db0928244c4c836cf3da5140e6e93db7756e2791ba99a21104ad3aa72 boost_1_62_0_b2.zip As always, the release managers would appreciate it if you download the archive of your choice and give building and using it a try. Please report both success and failure, and anything else that is noteworthy. Thanks! -- The release managers -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

4 9

Re: [boost] first steps to submitting - boost :: observers
by Bjorn Reese 19 Sep '16

19 Sep '16

On 09/17/2016 08:10 PM, Robert McInnis wrote: > https://github.com/tiny/boost_observers.git What are the advantages of this library over Boost.Signals2 [1]? Same question with regards to the Boost.Synapse [2] proposal. My impression from a brief look at your repository is that you need to focus more on thread-safety. Is there any way to avoid the overhead of thread synchronization in a single-threaded application? Observers are invoked while the mutex is locked, so observers cannot make calls on the subject. How does the lock-free mutex perform, especially when congested? Why is the lock-free mutex recursive? There are several member variables that are used as if they are atomic but they are not declared as such, e.g. Subject::_block, Numeric<T>::_x (think T == long long.) The Scope template can be replaced by lock_guard if you model the LockFreeMutex after the BasicLockable concept [3]. The thread_self() and thread_pid() functions can be replaced by this_thread::get_id(). Replace the hAtomic macro with a type alias. Use <cstdint> instead of <stdint.h> to reduce polution of the global namespace. [1] http://www.boost.org/doc/html/signals2.html [2] http://zajo.github.io/boost-synapse/ [3] http://en.cppreference.com/w/cpp/concept/BasicLockable

4 6

[density] version 7
by Giuseppe Campana 19 Sep '16

19 Sep '16

Hi to all, I’ve just merged to the master branch a major review of density, an header-only library of heterogeneous dense containers. Unfortunately this update includes some renamings. Anyway the new names are simpler and more explicative: heterogeneous_array, heterogeneous_queue, function_queue, lifo_array. The update consists of fixes and optimizations. The results of the benchmarks are included in the documentation. The container function_queue gives the best results, being many times faster than an std::queue of std::function’s (http://peggysansonetti.it/tech/density/html/func_queue_bench.html) The library is not yet ready for asking a formal review, but hopefully it will be in a few months. Html overview (now a little more schematic) and reference doc at http://peggysansonetti.it/tech/density/html/index.html Repository at https://github.com/giucamp/density/tree/master Giuseppe Campana.

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Fuzzy string search to the Boost String Algortihm
by Зайцев Александр 19 Sep '16

19 Sep '16

Hello. I want to discuss about some proposals. I am working on Levenshtein distance and Damerau-Levenshtein distance algortihms. I hope, that these implementations will be pulled to the Boost String library. But i think that we can add to the Boost String Library some more algorithms for fuzzy searhing. I mean these algortihms: Levenshtein distance Damerau-Levenshtein distance Bitap algorithm with modifications by Wu and Manber Spell-checker method N-gram method Signature hashing method BK-trees What do you think about this idea? If you think that it can be implemented to the Boost String Algo, i will start work on this list immediately. Best regards, Zaitsev Alexander.

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first steps to submitting - boost :: observers
by Robert McInnis 19 Sep '16

19 Sep '16

G'afternoon, This is my first time submitting to a public repo, please be gentle I'd like to submit a series of classes I have been using since '90. The initial set implements a thread safe subject/observer pattern. I have included a handful of example programs, two fairly trivial and the third more in-depth. All examples are single file examples to make compilation trivial. This is the first re-work of my original tools, making them more boost-friendly. I expect to add more default observer templates and observable objects, but that will come with time. WHY? -- The reason for these classes is to help insure the mathematical integrity of your data model in relation to your business rules. If at any time you were to change one of your data elements without updating all those dependent on it, then your data integrity would be compromised. These classes look to solve that. As an example: -- using namespace boost::observers ; Numeric<long> x, y, z ; // rules: y = x + 2; z = y * 3 ; x = 5 ; printf( "%d \n", z ) ; x = 1 ; printf( "%d \n", z ) ; -- Setting the rules properly, the classes allow for 'z' to be correct each time it's printed using code almost exactly like this. This will remove the possibility of accidently forgetting to trigger the rule update. WHERE? -- The repo can be found here: git clone https://github.com/tiny/boost_observers.git Any input on how to continue from this point would also be much appreciated. I have skype and ventrilo servers available if that helps. Thanks in advance, Rob -- Robert McInnis

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[release] Boost 1.62.0 - One week to close.
by Rene Rivera 16 Sep '16

16 Sep '16

Reminder.. Next week, on the 21st, the release will close for all changes. Except for extra ordinary and approved changes. Please exercise caution when merging changes to master branches. Remember that changes need to be well tested on the develop branches before going into master. And that changes at this point should be for critical problems. Thanks, the Release Team. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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[uuid] PR to remove auto-linking to advapi32 when BOOST_ALL_NO_LIB is defined
by Edward Diener 15 Sep '16

15 Sep '16

I don't know how to resolve a PR for uuid ( https://github.com/boostorg/uuid/pull/11 ). If a library exists only as a DLL and not as a static library should BOOST_ALL_NO_LIB still be considered in effect ? My viewpoint is 'no' but the person who created the PR believes that the BOOST_ALL_NO_LIB config macro should turn off any #pragma auto-linking in code even when their is no other way to use a library other than as a shared library. What I am afraid of is breaking user code even if BOOST_ALL_NO_LIB is defined by producing link errors. But perhaps I am wrong and this should be considered justified when BOOST_ALL_NO_LIB is being used.

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[algorithm] Musser-Nishanov sequence search algorithm
by Jeremy Murphy 15 Sep '16

15 Sep '16

Dear Boost community, most of you are probably familiar with Dave Musser, well known for his work on generic programming, introsort and more. What you maybe didn't know, and I didn't until not that long ago, is that he and Gor Nishanov also designed (based off KMP) and wrote a generic sequence search algorithm to compete with Boyer-Moore, etc, which apart from being competitively fast is ostensibly more generic than the others. You can read for yourself on Dave Musser's website: http://www.cs.rpi.edu/~musser/gp/algorithms.html By "more generic" I mean it has a fallback algorithm if the corpus does not have random-access iterators, and its behaviour can easily be tuned for the alphabet size to dramatic effect. (I haven't looked into the 'tunability' of BM, BMH, KMP, etc, so I'm not sure if this is a unique feature.) But at face value, it appears to have powerful features that the others lack without compromising performance, which is pretty neat. So I've been in contact with the original authors and with their permission am just playing the messenger to bring the algorithm to wider attention with the expectation that it is something we could really benefit from. What I hope for now is to have discussion on whether indeed it is an algorithm that we want, presumably alongside the others in Boost.Algorithm. My slightly more controversial thought is that, if no shortcomings or weaknesses are revealed, this could up being the superior search algorithm. I've opened a pull request on Boost.Algorithm with the code so everyone can play around with it if they want. https://github.com/boostorg/algorithm/pull/25 Looking forward to hearing what everyone thinks. Cheers. Jeremy

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[uuid][rational] Pushed bug fixes to 'master'
by Edward Diener 15 Sep '16

15 Sep '16

I pushed some bug fixes from 'develop' to 'master' for the uuid and rational libraries. The fixes had been tested on the 'develop' branch for a long time and the results showed that the fixes were fine. While none of the fixes were major I felt that the fixes were important enough to go in the upcoming Boost release if they are going to be picked up. I, and probably other members of CMT, should have been more proactive in pushing these fixes to 'master' sooner, once they showed green on the develop test matrix.

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Final Call for Extended Abstracts and Posters: International Conference on Information Society (i-Society 2016), Technical Co-Sponsored by IEEE UK/RI Chapter!
by David Brown, i-Society 2016 14 Sep '16

14 Sep '16

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[log] Boost 1.62 cannot compile log with Oracle Developer Studio 12.5
by Aparna Kumta 14 Sep '16

14 Sep '16

Compiling Boost.log with Oracle Developer Studio 12.5, we see the following failure: % "CC" -std=c++11 -library=stdcpp,CrunG3 -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_DATE_TIME_DYN_LINK=1 -DBOOST_FILESYSTEM_DYN_LINK=1 -DBOOST_LOG_BUILDING_THE_LIB=1 -DBOOST_LOG_DLL -DBOOST_LOG_HAS_PTHREAD_MUTEX_ROBUST -DBOOST_LOG_WITHOUT_DEBUG_OUTPUT -DBOOST_LOG_WITHOUT_EVENT_LOG -DBOOST_SPIRIT_USE_PHOENIX_V3=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_THREAD_BUILD_DLL=1 -DBOOST_THREAD_DONT_USE_CHRONO=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -DDATE_TIME_INLINE -DNDEBUG -D_XOPEN_SOURCE=500 -D__EXTENSIONS__ -D__STDC_CONSTANT_MACROS -D__typeof__=__typeof__ -I"../../.." -I"../../../libs/log/src" -c -o "../../../bin.v2/libs/log/build/sun/release/stdlib-gnu/threading-multi/posix/ipc_reliable_message_queue.o" "../../../libs/log/src/posix/ipc_reliable_message_queue.cpp" "../../../libs/log/src/posix/ipc_reliable_message_queue.cpp", line 61: Error: #error Boost.Log: Native 32-bit atomic operations are required but not supported by Boost.Atomic on the target platform. This seems to be a configuration issue. The following changes seems to work: 1) In boost/atomic/detail/platform/platform.hpp % !diff diff ./platform.hpp ./platform.hpp_orig 46c46 < #elif (defined(__GNUC__) || (__SUNPRO_CC >= 0x5130)) && (defined(__i386__) || defined(__x86_64__)) --- > #elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) 68c68 < #elif (defined(__GNUC__) || (__SUNPRO_CC >= 0x5130)) && defined(__sparc) --- > #elif defined(__GNUC__) && defined(__sparc_v9__) The above change causes the compilation to proceed further, however, it fails again with another configuration issue causing failure to build atomic library "CC" -std=c++11 -library=stdcpp,CrunG3 -xO4 -mt -erroff=%none -m32 -KPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_ATOMIC_SOURCE -DNDEBUG -I"../../.." -c -o "../../../bin.v2/libs/atomic/build/sun/release/stdlib-gnu/threading-multi/lockpool.o" "../../../libs/atomic/src/lockpool.cpp" "../../../boost/atomic/detail/ops_gcc_sparc.hpp", line 69: Error: The function "fence_before_store" must have a prototype. In boost/atomic/detail/ops_gcc_sparc.hpp, the following change seems to resolve the issue % !diff % diff ./ops_gcc_sparc.hpp ./ops_gcc_sparc.hpp_orig 69c69 < fence_before(order); --- > fence_before_store(order); 71c71 < fence_after(order); --- > fence_after_store(order); 110c110 < fence_before(order); --- > base_type::fence_before(order); 118c118 < fence_after(order); --- > base_type::fence_after(order); I will submit a PR for this change. Thanks, Aparna

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[filesystem] How to remove specific files from a directory?
by Andrzej Krzemienski 14 Sep '16

14 Sep '16

Hi, I wonder what is boost::filesystem recommendation for solving the following problem. I want to remove all files from a given directory that satisfy a certain predicate, e.g., only these whose names start with letter "s". It is my understanding that the calling filesystem::remove may invalidate the iterator, and therefore the following solution is incorrect: fsys::directory_iterator it{path}, itEnd{}; for ( ; it != itEnd ; ++it ) { if (predicate(*it)) fsys::remove(it->path()); } But, is the following guaranteed to work?: fsys::directory_iterator it{path}, itEnd{}; for ( ; it != itEnd ; ) { if (predicate(*it)) fsys::remove((it++)->path()); else ++it; } If not, does there exist a dedicated solution for solving this problem that would not require of me N traversals through the directory? Thanks, &rzej;

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[release] Boost 1.62.0 Beta 1
by Rene Rivera 14 Sep '16

14 Sep '16

The first beta packages for 1.62.0 beta 1 are now available: <https://sourceforge.net/projects/boost/files/boost/1.61.0.beta.1/> The SHA256 checksums are as follows: f7cc83e6a3b03cd7aa8822992aa3e36422cc2214644d69277ef55a4db51f44bd boost_1_62_0_b1.7z 4057993811e40b1fd4719675e44c2550b6c2379546192da2299c17fec9a3dddf boost_1_62_0_b1.tar.bz2 fb0c10b625c5ec47cc837b54740540e400c59571b2eabf427c00f32bffc6ca70 boost_1_62_0_b1.tar.gz b38ef21c43c5ff814a2144bc23871c134164e7f51c71672d0f49a44636fb50b5 boost_1_62_0_b1.zip As always, the release managers would appreciate it if you download the archive of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. Thanks! -- The release managers -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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