- Boost - lists.preview.boost.org

Getting Started
by ishan garg 25 Dec '17

25 Dec '17

Hello everyone, I am new to OpenSource Development. I know basics of C++ and acquainted with it's STL. I have basic knowledge of DSA as well as few git commands (clone, push, commit, etc). I wanted to know how can I start contributing to BOOST library? Thanks in Advance -- Regards, Ishan Garg

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library maintainer list
by Robert Ramey 24 Dec '17

24 Dec '17

I'm curious about how I might go about discovering and contacting the person(s) who might be maintaining a particular library. As an example, I have a couple of questions about possible enhancements to the boost interval library (what about making this constexpr?). Ideally, I'd like to see a summary page for each library which steers me to the appropriate links like issues, comments/issues page, maintainence status etc. such as the boost library incubator has. Actually, I considered just adding these pages to the boost library incubator website, but I didn't have the motivation and it might stir a pot I personally don't want to stir right now. Robert Ramey

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regarding mailing list traffic
by Mudit Sharma 22 Dec '17

22 Dec '17

Dear All, I have recently not been receiving the daily Boost mailing list digest, is there some maintenance work going on ? Thanks! M

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[date_time] Trac 13194 - %e posix time_input_facet specifier behavior
by James E. King, III 21 Dec '17

21 Dec '17

https://svn.boost.org/trac10/ticket/13194 Just looking at this one, and looking at the documentation, it states that %e is the same as %d however when the value is less than 10, a leading space is to be used instead of a leading zero. The example in the description has a flaw, I believe, and I commented on that. Do folks agree with my comment? Should parsing fail if it says "December 5" (with one space) and the format string is "%B %e"? Valid input would be "December 5" (with two spaces). I also found that the code blindly ignores delimiter specifiers, so I opened a github issue for it: https://github.com/boostorg/date_time/issues/53. Comments appreciated there as well. Thanks, Jim

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[endian] undefined behaviour in boost.endian
by Arvid Norberg 21 Dec '17

21 Dec '17

Hi, I've submitted an issue to the github project for boost.endian. I'm starting to wonder if this is in fact not the preferred channel for reporting issues. There are at least two separate issues causing undefined behaviour to be invoked in boost.endian. The first one is fundamentally based on the assumption that if the target architecture is x86, the C++ alignment requirements don't apply. I've posted more details here: https://github.com/boostorg/endian/issues/21 with a proposed patch here: https://github.com/boostorg/endian/pull/22 The second issue involves shifting negative integers, both invoking implementation defined and undefined behaviour. I don't have a patch to fix the issue, just to extend the tests to exercise the problem, which is then detectible with the undefined behaviour sanitizer. Patch is here: https://github.com/boostorg/endian/pull/24 I would really appreciate it if someone could review these and/or suggest a better venue than github to propose patches. thanks! -- Arvid Norberg

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[build] Currently broken with Xcode 8?
by John Maddock 20 Dec '17

20 Dec '17

Current develop appears not to build with XCode 8.0 causing Travis tests to fail, for example: https://travis-ci.org/boostorg/config/jobs/318188889 Thanks, John. --- This email has been checked for viruses by AVG. http://www.avg.com

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[release] Boost 1.66.0
by Daniel James 19 Dec '17

19 Dec '17

Release 1.66.0 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 N new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.66.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.66.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Vladimir Prus, Marshall Clow, Eric Niebler, Daniel James, Beman Dawes

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[release] 1.67.0 open for merging
by Daniel James 19 Dec '17

19 Dec '17

The master branch is open for merging all stable changes from develop, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging does not require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html Release schedule explanation: https://github.com/boostorg/boost/wiki/Release-Schedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Boost Release Team

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[release] 1.66.0 post-beta merges
by Daniel James 19 Dec '17

19 Dec '17

The master branch is is now open for post-beta merges, but only as described in the Post-Beta Merge Policy. See <https://github.com/boostorg/boost/wiki/Release-Beta-Merge-Policy>

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[release] Boost 1.66.0 Release Candidate 2
by Daniel James 18 Dec '17

18 Dec '17

The second release candidates for the 1.66.0 release are now available at: <https://dl.bintray.com/boostorg/prerelease/> The in progress release notes are: <http://www.boost.org/users/history/in_progress.html> Library documentation is available at: <http://www.boost.org/doc/libs/1_66_0/> The SHA256 checksums are as follows: 596389389c005814ecb2a6b64c31dccd2c3e6fbc5a802b4dfada999ae5844628 boost_1_66_0_rc2.7z 5721818253e6a0989583192f96782c4a98eb6204965316df9f5ad75819225ca9 boost_1_66_0_rc2.tar.bz2 bd0df411efd9a585e5a2212275f8762079fed8842264954675a4fddc46cfcf60 boost_1_66_0_rc2.tar.gz e1c55ebb00886c1a96528e4024be98a38b815115f62ecfe878fcf587ba715aad boost_1_66_0_rc2.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.

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boost-1.66.0 tag?
by James E. King, III 18 Dec '17

18 Dec '17

I just refreshed Boost.Uuid locally and don't see a boost-1.66.0 tag. I had assumed this would be added by the upstream build and release procedure? Am I supposed to make that tag? - Jim

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[chrono][timer][release] Non-inline functions in inlined headers
by Daniel James 14 Dec '17

14 Dec '17

Hi, We've had a link problem reported. for this code on Visual Studio, using auto-linking: #include "boost\chrono.hpp" #include "boost\timer\timer.hpp" int main() { auto now = boost::chrono::steady_clock::now(); boost::timer::cpu_timer cput; return 0; } I haven't got the binaries installed yet, so I haven't reproduced it, but I think it's caused because timer now includes the chrono headers using BOOST_CHRONO_HEADER_ONLY, and in the chrono inlined headers not all functions are BOOST_CHRONO_INLINE. It looks like this problem was always in chrono, but BOOST_CHRONO_HEADER_ONLY was widely used enough for it to be detected. I'd quite like to fix this for 1.66.0, which requires either reverting the change to timer, or fixing the problem in chrono. The error is in chrono, but I'm more inclined to revert the change in timer for this release, as it's a less disruptive way of quickly fixing the problem. https://github.com/boostorg/timer/pull/5

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Building only x86 /MDd and /MT on msvc 2017
by Fredrik Stax{ng 13 Dec '17

13 Dec '17

The docs says For instructions on how to build only specific variants, please ask on the Boost.Build mailing list. but I gmane gives a 411 for Boost.Build so I ask the question here. For 1.60.0 I used this cd modular-boost rem call .\bootstrap .\b2 headers .\b2 toolset=msvc variant=debug address-model=32 link=static threading=multi runtime-link=shared .\b2 toolset=msvc variant=release address-model=32 link=static threading=multi runtime-link=static Has this changed? -- Fredrik Stax\"ang | rot13: sfgk(a)hcqngr.hh.fr This is all you need to know about vi: ESC : q ! RET

1 0

[beast] Security
by Phil Endecott 13 Dec '17

13 Dec '17

Dear All, To what extent do we think that Beast should be "secure"? I am thinking mostly about handling malicious input. Has it been reviewed by anyone with specific experience of how HTTP can be attacked? Has it been "fuzzed"? Regards, Phil.

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linker error in 1.66 rc1 (regression from 1.65.1)
by Mark Incley 13 Dec '17

13 Dec '17

Hi, Using Visual Studio 2017 15.5, the following minimal test case causes a linker error with Boost 1.66 RC1 but builds fine with 1.65.1: Produces... 1>------ Build started: Project: aZ80, Configuration: Debug Win32 ------ 1>libboost_timer-vc141-mt-gd-x32-1_66.lib(cpu_timer.obj) : error LNK2005: "public: static class boost::chrono::time_point<class boost::chrono::steady_clock,class boost::chrono::duration<__int64,class boost::ratio<1,1000000000> > > __cdecl boost::chrono::steady_clock::now(void)" (?now@steady_clock@chrono@boost@@SA?AV?$time_point@Vsteady_clock@chrono@boost@@V?$duration@_JV?$ratio@$00$0DLJKMKAA@@boost@@@23@@23@XZ) already defined in libboost_chrono-vc141-mt-gd-x32-1_66.lib(chrono.obj) 1>libboost_timer-vc141-mt-gd-x32-1_66.lib(cpu_timer.obj) : error LNK2005: "double __cdecl boost::chrono::chrono_detail::get_nanosecs_per_tic(void)" (?get_nanosecs_per_tic@chrono_detail@chrono@boost@@YANXZ) already defined in libboost_chrono-vc141-mt-gd-x32-1_66.lib(chrono.obj) 1>C:\Projects\aZ80\vs\Debug\aZ80.exe : fatal error LNK1169: one or more multiply defined symbols found Swapping the order of the includes appears to workaround the problem. Mark. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[release] Boost 1.66.0 Release Candidate 1
by Daniel James 11 Dec '17

11 Dec '17

The release candidates for the 1.66.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.66.0/source/> The in progress release notes are: <http://www.boost.org/users/history/in_progress.html> Library documentation is available at: <http://www.boost.org/doc/libs/1_66_0/> The SHA256 checksums are as follows: c9d29486dd12f19d321da65eb5f0a157ec0f0edfd4701ade48c644310c8f0676 boost_1_66_0_rc1.7z 6232f7e7873b2d1f112fb62c726f7066e9a7e0643ed2aac7d31d20bf5749fbc0 boost_1_66_0_rc1.tar.bz2 30ad6d1c7380d6e6a87ce1bc54388ab957de67a2e8fa44dd3c106eafad0f6ac2 boost_1_66_0_rc1.tar.gz cd2c64f243c89e04329e94f3b803f0744171b44fee7a8b4e3256b3a625dcbd1c boost_1_66_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.

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Info: Boost.Config is older than your compiler version - message is surprising
by Paul A. Bristow 11 Dec '17

11 Dec '17

I've just updated to the latest and greatest Visual Studio 15.5 and also got my Boost develop branch up-to-date. But I'm still getting this message: "Info: Boost.Config is older than your compiler version - probably nothing bad will happen - but you may wish to look for an updated Boost version. Define BOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE to suppress this message." I've just rebuilt my library files that have the new -x64- x32 in the name (great - but grrrr because I have had to change all my command files to generate them, previously in /x64 and /win32 folders ;-) The library files have names like libboost_chrono-vc141-mt-x64-1_66.lib so version number is still at 1.66 (a fact confirmed by the config_info Boost version 106600) The config_info.txt output is attached. So I am surprised to get this potentially useful warning. It would *much* more helpful if the warning told which version number of both compiler and Boost? (Just like the 'File not found' message that provokes "Which *&%$%^!!ing file" expletives). Paul PS The Good news is that defining BOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE quiets as promised. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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Help requested for boost documentation for polymorphic_value
by Jonathan Coe 11 Dec '17

11 Dec '17

I have been preparing polymorphic_value for submission to boost. I have draft documentation here: https://drive.google.com/open?id=1xpD8s8zDzedVDDlqjsl1JtYGaJBHWoGy but am having problems generating doxygen docs. A forward declaration seems to stop generation of docs for methods of polymorphic_value. I'm at a loss as to why doxygen is not working properly for boost doc (it works fine when run in isolation) and would be grateful for any insight anyone can offer. I suspect it's a simple problem but I'm not very experienced with doxygen and am new to the boost docs tools. source is here: https://github.com/jbcoe/polymorphic_value/tree/boost regards, Jon

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Optional third-party libraries
by James E. King, III 09 Dec '17

09 Dec '17

The boost documentation on the web site talks about building boost from source, but I don't see information on how to leverage optional third party libraries easily accessible in the documentation from the place the user will most likely end up: "Building From Source". This information seems to be tucked away in documentation of various components, making it difficult to actually build a complete boost. I think it would be a good idea to bring this information up to the top level build instructions, at the very least itemize these third party packages and then link to the relevant project-specific documentation pages that talk about configuring to use them. Here are the third party optional libraries I know about so far and the libraries that use them: bzip2 (iostreams) iconv (locale - if icu not available) icu (locale, regex) lzma (iostreams) openssl (asio, beast) pthread-win32 (sync, thread) zlib (beast, gil, iostreams) Any others? Would folks find it useful if this information was part of the standard "Building From Source" sections of the upper layers of documentation? Thanks, Jim

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[config] msvc-15.5, updating tests
by John Maddock 09 Dec '17

09 Dec '17

While working on updating Boost.Config for msvc-15.5 I've managed to break the test case for boost_no_cxx17_iterator_traits (both GCC and msvc agree on this) but can't see what's wrong :( The change is this one: https://github.com/boostorg/config/commit/305f5a58ef879037b0fd9fdaa8e05615c… which removes use of std::iterator as a base class. Anyone any ideas? Many thanks, John. --- This email has been checked for viruses by AVG. http://www.avg.com

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[release] Boost 1.66.0 Beta 1 Release Candidate 1
by Daniel James 09 Dec '17

09 Dec '17

The release candidates for the 1.66.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.66.0.beta.1/source/> The SHA256 checksums are as follows: 0e137e61069e95f61fe0e46aa4a5432e65e209e87d470ea3c15b0ea1327583ac boost_1_66_0_b1_rc1.7z eff4854c1a672830c55fd2323ebe42d5d83e0f7a3d0a9d354d8bf55289831fa0 boost_1_66_0_b1_rc1.tar.bz2 f4fb07aa1ec639707570e42a848796d9a8155f23d1ece0f0a6a0cbee99807038 boost_1_66_0_b1_rc1.tar.gz d5f480441223f45427199697edbdd78145499084f835597247a452d2a7e1e798 boost_1_66_0_b1_rc1.zip The in progress release notes are at: <http://www.boost.org/users/history/in_progress.html> And the documentation is at: <http://www.boost.org/doc/libs/1_66_0_beta1/> 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.

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[beast] Security Review: Hybrid Application Assessment
by Vinnie Falco 09 Dec '17

09 Dec '17

Since 2005, Bishop Fox has provided security consulting services to the Fortune 1000, high-tech startups, and financial institutions worldwide. The author of Beast, Vinnie Falco, engaged Bishop Fox to assess the security of the Boost C++ Beast HTTP/S networking library. The following report details the findings identified during the course of the engagement, which started on September 11, 2017. The assessment team conducted a hybrid application assessment of the Beast library. Bishop Fox’s hybrid application assessment methodology leverages the real-world attack techniques of application penetration testing in combination with targeted source code review to thoroughly identify application security vulnerabilities. These full-knowledge assessments begin with automated scans of the deployed application and source code. Next, analyses of the scan results are combined with manual review to thoroughly identify potential application security vulnerabilities. In addition, the team performs a review of the application architecture and business logic to locate any design-level issues. Finally, the team performs manual exploitation and review of these issues to validate the findings. <https://vinniefalco.github.io/BeastAssets/Beast%20-%20Hybrid%20Application%…> Note: The permessage-deflate vulnerability described in the report is confirmed to be fixed in the version of Beast which is included in Boost 1.66.0 Thanks

1 0

Requesting endorsements for YAP review
by Zach Laine 07 Dec '17

07 Dec '17

I mailed the list several months ago about YAP, an expression template library written against C++14 and later standards. The sources can be found here: https://github.com/tzlaine/yap and online docs here: https://tzlaine.github.io/yap I'd like to put this in the review queue, and so I'm looking for endorsements for this. At the time of my initial emails, there was some interest, but not much. Expression templates are a niche technology, so this makes sense. I'm trying to make ETs less expert friendly, so that they leave their experts-only niche. I feel this library does a fairly good job of that. If you do too, please endorse! Thanks, Zach

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Discovering and handling missing override keyword in project conversion
by James E. King, III 06 Dec '17

06 Dec '17

I'm in the middle of converting a large project from C++03 to C++14, and of course crossing the C++11 gap, I want identify all of the places where the override keyword should be used but is not, and add it. When I turned on -Wsuggest-override in gcc-7.2 I got a fair number of warnings from boost code, for example: ...boost/program_options/value_semantic.hpp:304:14: error: â€˜bool boost::program_options::typed_value<T, charT>::is_composing() const [with T = std::basic_string<char>; charT = char]â€™ can be marked override [-Werror=suggest-override] bool is_composing() const { return m_composing; } ^~~~~~~~~~~~ ...boost/program_options/value_semantic.hpp:306:18: error: â€˜unsigned int boost::program_options::typed_value<T, charT>::min_tokens() const [with T = std::basic_string<char>; charT = char]â€™ can be marked override [-Werror=suggest-override] unsigned min_tokens() const ^~~~~~~~~~ ...boost/program_options/value_semantic.hpp:315:18: error: â€˜unsigned int boost::program_options::typed_value<T, charT>::max_tokens() const [with T = std::basic_string<char>; charT = char]â€™ can be marked override [-Werror=suggest-override] unsigned max_tokens() const { ^~~~~~~~~~ ...boost/program_options/value_semantic.hpp:325:14: error: â€˜bool boost::program_options::typed_value<T, charT>::is_required() const [with T = std::basic_string<char>; charT = char]â€™ can be marked override [-Werror=suggest-override] bool is_required() const { return m_required; } ^~~~~~~~~~~ (There were others - this is just a small sample) This is probably not the first time this has been brought up, but there is no BOOST_OVERRIDE (or BOOST_FINAL, for that matter) definition in Boost.Config that would allow Boost itself to be compatible with C++03 or C++11 cleanly relative to this language feature. I found a number of posts about this issue elsewhere. Has this issue been discussed here before? I could spend some time adding this to Boost.Config and then making boost compile cleanly with cxxstd=03,11 toolset=gcc-7 cxxflags="-Wsuggest-override", as it would help support a more complete conversion to the new language level for projects, and it would enable existing projects to turn on the warning to improve their code, as well as improve Boost. Thoughts? - Jim

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[release] 1.66.0 closed for release
by Daniel James 06 Dec '17

06 Dec '17

The master branch is now closed for all changes except by permission. The commit-bot isn't running on master, so the super project will need to be manually updated for any changes. If all goes well, the release candidate should be out this weekend. You can still modify the release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_66_0.q…> Thanks, -- The Boost Release Team

1 0

Policy for breaking changes
by Louis Dionne 05 Dec '17

05 Dec '17

Hi all, So far, I've been careful about not doing any breaking changes to Hana. Hana obeys semantic versioning, and I'm accumulating desirable breaking changes until I'm ready to publish a new major version. I'm wondering what's the policy for major breaking changes with Boost libraries. For example, let's say I wanted to do an update of Hana with C++17 features; this would be a large breaking change, with all kinds of API changes, etc.. - Are such drastic changes prohibited altogether? Or perhaps they’re not prohibited but there’s historical evidence showing it’s always a bad idea? - Do such changes require going through a mini review? - Is it customary to leave the old version of the library there in a separate directory (or put the new one in a separate directory)? I think Spirit does that, e.g. Spirit Classic is still available IIRC. I think I know the answer to these questions from observing other author's behavior, but I'd like to see what the community thinks about this. It has an impact on the Boost libraries as a whole, since a major breaking change in one library could prevent users from updating Boost as a whole, which has an impact on all of us. I'm looking forward to hearing other people's thoughts on the matter. Thanks, Louis

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[type_index] type names string cross-platformness
by Damien Buhl 05 Dec '17

05 Dec '17

Dear Boost, MSVC differs from GCC & Clang in the way it present the pretty_name of a type_info within Type Index. Indeed for the following type : struct why {}; Is presented as `struct why` while on GCC it is `why`. Is there any reason why pretty_name wouldn't strip / add the information from one of the compiler in order to reach a cross-plaftorm string name of types ? MSVC:http://rextester.com/QNMB58390 <http://rextester.com/QNMB58390> GCC: http://coliru.stacked-crooked.com/a/1aa52003605d4936 Would such a patch to the library be possible & welcome ? Best regards, -- Damien Buhl Software Developer +33 6 77 43 10 05

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MSVC 15.5 support
by Olaf van der Spek 05 Dec '17

05 Dec '17

Hi, 15.5 Preview has been released: https://blogs.msdn.microsoft.com/vcblog/2017/10/11/productivity-structure-v… > Unknown compiler version - please run the configure tests and report the results How do I do this? Could this message be updated to indicate it comes from Boost? Gr, -- Olaf

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Announcement: Faber, a new build system based on bjam
by Stefan Seefeld 05 Dec '17

05 Dec '17

Hello, about a year ago I started to experiment with a new Python frontend for Boost.Build. After many iterations of prototyping things are starting to fall into place, and the project stabilizes. I'm thus happy to announce the release of Faber version 0.2: code: https://github.com/stefanseefeld/faber docs: https://stefanseefeld.github.io/faber While Faber retains most of the features from Boost.Build, it is redesigned from the ground up. bjam is still used as scheduling engine, but everything else is written in Python. In particular, Jamfiles are replaced by fabscripts, which are essentially Python scripts. The project contains a range of examples to demonstrate various simple use-cases, from a simple "hello world" example to demos involving autoconf-style config checks, and unit testing. I have added build logic to Boost.Python to use Faber on Travis-CI as well as AppVeyor, which also is a good litmus test for Faber's capabilities. I'd be very interested in feedback as well as contributions. Perhaps it might become possible one day to integrate Faber with other efforts to add a Python frontend to Boost.Build. Regards, Stefan -- ...ich hab' noch einen Koffer in Berlin...

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BOOST_PRAGMA_MESSAGE?
by Peter Dimov 04 Dec '17

04 Dec '17

In what module does the following utility macro: #if defined( __GNUC__ ) #define BOOST_PRAGMA_MESSAGE_IMPL_1( x ) _Pragma( #x ) #define BOOST_PRAGMA_MESSAGE( x ) BOOST_PRAGMA_MESSAGE_IMPL_1( message( x ) ) #elif defined( _MSC_VER ) #define BOOST_PRAGMA_MESSAGE_IMPL_2( x, f, ln ) __pragma( message( f "(" #ln "): note: " x ) ) #define BOOST_PRAGMA_MESSAGE_IMPL_1( x, f, ln ) BOOST_PRAGMA_MESSAGE_IMPL_2( x, f, ln ) #define BOOST_PRAGMA_MESSAGE( x ) BOOST_PRAGMA_MESSAGE_IMPL_1( x, __FILE__, __LINE__ ) #else #define BOOST_PRAGMA_MESSAGE( x ) #endif belong? Use: BOOST_PRAGMA_MESSAGE( "something" ) MS output: .\testbed.cpp(10): note: something g++ output: testbed.cpp:10:35: note: #pragma message: something BOOST_PRAGMA_MESSAGE( "something" ) ^

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[accumulators] No maintainer?
by Sergiu Deitsch 04 Dec '17

04 Dec '17

Boost.Accumulators does not seem to have an active maintainer anymore. My PR hast been waiting for any reaction from a maintainer for over a year now. Can someone of the Boost devs take a look at my (pretty trivial) PR at https://github.com/boostorg/accumulators/pull/5 and possibly merge it?

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[hash][array][stacktrace][type_index] Adding noexcept to hash
by Daniel James 04 Dec '17

04 Dec '17

Hi, I want to add noexcept support to the hash library, but a few libraries (array, stacktrace, type_index, maybe more) forward declare hash_range for themselves, causing errors if I add a noexpect specifier to hash_range. If I move hash_fwd.hpp into the core module, so that it doesn't add a dependency on the functional module, would they be okay with including it from there? thanks, Daniel

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Re: [boost] PSA: Travis OS X bottleneck, <cxxstd> new Boost.Build feature
by Robert Ramey 02 Dec '17

02 Dec '17

On 11/29/17 1:10 AM, Boris Kolpackov wrote: > In this light, I think it makes more sense to ask Boost users > who are using Boost on Mac OS to contribute hardware resources > for CI testing. This is the right idea. Let's go the full monte and take it to it's logical conclusion. a) Encourage users to run tests on the libraries they use by making testing more user friendly. b) Create a CMake or CMake-like dashboard where users can more or less automagically post their results to a common database. Presumable boost regression.py does something similar already. c) Create a program to permit display of this giant "data cube" according to the needs of the user/developer. My personal contribution to moving in this direction can be found at https://github.com/robertramey/library_status This permits me to: a) run the serialization test suite with boost build. This is a single button which builds all the libraries that the serialization depends upon, and runs all the tests. b) The results are displayed on a giant cumulative matrix which permits me to see which tests are failing on which platforms. Here is a recent copy of that matrix http://htmlpreview.github.com/?https://github.com/robertramey/library_statu… more information is available here: http://htmlpreview.github.com/?https://github.com/robertramey/library_statu… If this idea were implemented we would have: a) recent tests on all platforms actually being used regardless of how obscure. b) an easily browsable data base of test results. c) less dependency on centralized CI testing resources d) less pressure on boost testers e) more people participating and being a member of the boost community - helping to promote the "Boost Brand (c)" f) Since Appveyor, Travis, regression.py, and individual users would be posting all results to a common database, we'd be decoupling test results presentation from any particular testing platform. g) Should CMake solution every get accepted, it could easily be adjusted to post the the database as well. Boost needs this going back at least a decade. Robert Ramey

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[release] 1.66.0 closing for release on Wednesday
by Daniel James 02 Dec '17

02 Dec '17

There's still a little time for any remaining bug fixes, documentation updates and release notes. Schedule: 6 Dec - Closed for all changes, except by permission of a release manager 9 Dec - Closed for all changes 13 Dec - Boost 1.66.0 release You can edit the release notes here: https://github.com/boostorg/website/blob/master/feed/history/boost_1_66_0.q…

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[contract] move operations and class invariants
by Lorenzo Caminiti 01 Dec '17

01 Dec '17

Hello all, This is not really a question about Boost.Contract, but more a question on how contract programming interacts with C++ move operations. C++ requires that moved-from objects can still be destructed. Because contract programming requires class invariants to hold at destructor entry, it follows that moved-from objects must still satisfy class invariants. That sounds restrictive... and it might force the class invariants to be empty. For example, for vector a class invariant is size() <= capacity(). Should that sill hold after the vector has been moved? That means I can still call size() and capacity() on a moved-from object, which might not be the case. If some sort of moved() function could be called on a moved-from object, the invariants could be programmed as follow to work around this issue: class vector { void invariant() cont { if(!moved()) BOOST_CONTRACT_ASSERT(size() <= capacity()); ... // Only invariants that are truly needed to execute the destructor. } bool moved() const; public: vector(vector&& other) { boost::contract::check c = boost::contract::constructor(this) .postcondition([&] { BOOST_CONTRACT_ASSERT(!moved()); BOOST_CONTRACT_ASSERT(other.moved()); }) ; ... } ... }; I'm not really sure... What do you think? Do you know if this topic "C++ move & class invariants" has already been discussed somewhere? Thanks. --Lorenzo

6 11

Re: [boost] [contract] move operations and class invariants
by Peter Dimov 01 Dec '17

01 Dec '17

Lorenzo Caminiti wrote: > > read() can fail, so you can drop its "valid" precondition and just fail > > when the handle is invalid. > > Calling read() on a moved-from object so violating its is_valid() > precondition is a bug, not a run-time error while reading the file. The > precondition legitimately remains in place to catch bugs, even after it is > noted that read() can fail because of file-system or other run-time > errors. On one hand, you want to have a precondition. On the other, you say that if you have the precondition, the class would be crippled and not very useful: >> 2. How useful is a class like the one above with "crippled" invariants >> and is_valid() preconditions on all its useful public methods like >> read()? The answer seems to be: not very useful. These are contradictory. Either the class that has preconditions is crippled and not very useful, in which case we drop the preconditions as I suggest; or it's useful, in which case we keep them.

1 0

[spirit] x3 status and docs?
by Andrey Semashev 29 Nov '17

29 Nov '17

Hi, I'm wondering what is the status of Boost.Spirit x3? Is it considered stable and ready for production use? If yes, how can I find its docs? There seem to be no mention of x3 in the docs on the Boost website.

3 2

[histogram] Working with standard algorithms
by Bjorn Reese 29 Nov '17

29 Nov '17

I would like to see a better integration between boost.histogram and standard algorithms, especially those from <numeric>. Today they do not work together because the dereference operator of the axis iterator returns a pair (index and content) rather than the content. An example of where standard algorithms could be useful is calculating the cumulative distribution of a one-dimensional histogram, which ought to be a simple as: auto& axis = h.axis(); std:partial_sum(axis.begin(), axis.end(), axis.begin()); Another example is ranking a set of histograms based on the cosine similarity [1] using std::inner_product(). [1] https://en.wikipedia.org/wiki/Cosine_similarity

2 4

[release][fusion] Permission to merge
by Kohei Takahashi 29 Nov '17

29 Nov '17

Hi release manager, I'd like to merge a PR, which fixes a regression on buggy compiler. https://github.com/boostorg/fusion/pull/162 Boost.regression shows the test was passed on develop. Regards, Kohei Takahashi

1 0

[Build] x32
by Olaf van der Spek 28 Nov '17

28 Nov '17

Hi, > libboost_system-vc141-mt-gd-x32-1_66.lib Why is this named x32? AFAIK the normal name is x86. -- Olaf

5 4

Re: [boost] Adding polymorphic_value to boost
by Phil Endecott 28 Nov '17

28 Nov '17

Peter Dimov wrote: > You can have > > vector<polymorphic_value<Shape>> v; > > and then > > v.push_back( Circle(10) ); > v.push_back( Ellipse(10, 15) ); > v.push_back( Square(11) ); Good example. Yes please. There's another way of implementing this, though; rather than pointing to the object in the heap you can store it in-place by allocating enough space for the largest possible derived subclass: class Base { ... }; class Derived: public Base { ... }; template <typename B> class polymorhpic_value_2 { B base; char enough_space_for_dervided_classes_members[1024]; public: template <typename D> // requires D is same as or derived from B void operator=(const D& d) { B::~B(this); new (this) D(d); } }; polymorphic_value_2<Base> p; Derived d; p = d; That's just a sketch; many details omitted! There are some obvious advantages and disadvantages of each approach and I'm definitely not saying this is better than the pointer-to-heap design. But I mention it for this reason: * If your proposed interface for polymorphic_value could also work for this method of implementation, then it is probably a better interface. > It's unfortunate we have to use -> instead of . but that's what's available. There have been proposals for operator. ; has this been evaluated to see how it would work with them? Similarly the unified a.b() vs. b(a) syntax proposal. Regards, Phil.

4 6

Outcome v2 peer review dates set
by Niall Douglas 28 Nov '17

28 Nov '17

Outcome v2 will be up for its post-peer-review second review between Friday 19th January and Sunday 28th January with Charley Bay once again serving as review manager. In case you'd like to give it a whirl before then: Docs: https://ned14.github.io/outcome/ Single file edition: https://github.com/ned14/outcome/raw/develop/single-header/outcome.hpp Boost edition repo: https://github.com/ned14/boost-outcome Standalone edition repo: https://github.com/ned14/outcome List of changes since v1: https://github.com/ned14/outcome#changes-since-v1 Compilers needed: GCC 6, clang 4, VS2017 (C++ 14 minimum, C++ 20 preferred) Acknowledgements ---------------- This post-peer-review complete rebuild of Outcome was actually a collaborative effort by a number of the Boost community, and it has been significantly influenced for it. I'd firstly like to thank Charley for taking on the role of review manager for a second time, especially given that he knows from the first time what an awful lot of work it's going to be for him. I am *hoping* that seeing as v2 Outcome is literally a tick box set of the changes you guys recommended last time, that this review will be a quick and simple review. We shall see. I'd like to thank Andrzej for writing the beginning of the tutorial. It set the tone and pacing which I then extended to the rest of the tutorial, and I think the benefit of that shows through as this should be a vast improvement on the (many) v1 tutorials. Andrzej also found many bugs, asked many clever "stupid questions", and acted as a constant peer reviewer throughout the development of v2, including suggesting the present design for payload transport. Andrzej has had a huge influence in the shape, and direction, of this library. I cannot thank him enough, and although he declined being listed as coauthor, I'm thinking of "special thanks to" or something like that in the authorship list as he went above and beyond in his contribution. I'd like to thank Jonathan Müller for doing so much work on his Standardese tool to support Outcome. The current reference API docs on the Outcome website are but a wisp of what will hopefully be in place by the time of the review. Jonathan has had to wrestle with many libclang demons smoked out by Outcome pushing the state of the art, and will have to wrestle with many more yet, but already the huge improvements over the doxygen reference API docs are evident. If anybody has any questions or feedback between now and the review, please let rip. Otherwise thanks for reading! Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

1 0

Fwd: Using 'detail' folder from a another Boost library
by Jean Guegant 27 Nov '17

27 Nov '17

Hi everyone, I am trying to unify the way Boost.Beast and Boost.Asio pick an implementation of string_view (std::experimental::string_view, std::string_view). In order to do so, I am including the header file <boost/asio/detail/string_view.hpp> within <boost/beast/core/string.hpp> (see PR: https://github.com/boostorg/ beast/pull/910/files). Is that a bad practice to include the a "detail" folder from another library? If so, what would you recommend to solve my unification problem? Sincerely, Jean

2 1

Getting started with open source
by Faisal Riyaz 26 Nov '17

26 Nov '17

Hi, I am Faisal.I am new to open source community.I am familiar with C and C++ language.I am pursuing computer engineering and presently i am in first year.I am interested in contributing to your organisation and learn some stuff. It will be very helpful for me if someone can help me get started. Faisal Riyaz

1 0

[release][build] Permission to merge
by Jürgen Hunold 22 Nov '17

22 Nov '17

Hi! I'd like to merge commit e07c805e to master. This fixes https://github.com/boostorg/build/issues/236 with my PR from https://github.com/boostorg/build/pull/263 Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

2 1

[optional] regression failures on Linux teeks
by Lorenzo Caminiti 22 Nov '17

22 Nov '17

Hello all, I see the following Boost.Option regression test failures on develop branch: http://www.boost.org/development/tests/develop/developer/optional.html === error 1 === Test output: teeks99-02-dc3.7-14-Docker-64on64 - optional - optional_test_conversions_from_U / clang-gnu-linux-3.7~c++14 Rev 05c2033df7b99d19f4939bf81ca2aeeec592993d / Fri, 03 Nov 2017 00:24:42 +0000 Compile [2017-11-03 01:39:15 UTC]: fail "clang++-3.7" -c -x c++ -Wno-c99-extensions -std=c++14 -O0 -g -fno-inline -Wall -g -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -I".." -o "/var/boost/run/results/boost/bin.v2/libs/optional/test/optional_test_conversions_from_U.test/clang-gnu-linux-3.7~c++14/debug/threadapi-pthread/optional_test_conversions_from_U.o" "../libs/optional/test/optional_test_conversions_from_U.cpp" In file included from ../libs/optional/test/optional_test_conversions_from_U.cpp:12: In file included from ../boost/optional/optional.hpp:64: ../boost/optional/detail/optional_config.hpp:152:48: error: expected value in expression # if BOOST_WORKAROUND(BOOST_GCC, >= 50000) && ^ 1 error generated. === error 2 === Test output: teeks99-02-dc5-1z-lc-Docker-64on64 - optional - optional_test_conversions_from_U / clang-gnu-linux-5.0~c++1z~lc Rev 420dd51fb237f5e75cae0aeb01ec427717e4a748 / Sat, 04 Nov 2017 15:00:43 +0000 Compile [2017-11-04 15:49:56 UTC]: fail "clang++-5.0" -c -x c++ -Wno-c99-extensions -std=c++1z -stdlib=libc++ -isystem/usr/include/libcxxabi -O0 -g -fno-inline -Wall -g -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -I".." -o "/var/boost/run/results/boost/bin.v2/libs/optional/test/optional_test_conversions_from_U.test/clang-gnu-linux-5.0~c++1z~lc/debug/threadapi-pthread/optional_test_conversions_from_U.o" "../libs/optional/test/optional_test_conversions_from_U.cpp" In file included from ../libs/optional/test/optional_test_conversions_from_U.cpp:18: In file included from ../boost/core/lightweight_test.hpp:25: In file included from /usr/include/c++/v1/iostream:38: In file included from /usr/include/c++/v1/ios:216: In file included from /usr/include/c++/v1/__locale:15: /usr/include/c++/v1/string:1942:14: error: expected ';' at end of declaration _NOEXCEPT ^ /usr/include/c++/v1/string:1947:9: error: expected unqualified-id _NOEXCEPT ^ /usr/include/c++/v1/__config:368:21: note: expanded from macro '_NOEXCEPT' # define _NOEXCEPT noexcept ^ 2 errors generated. === The first error only shows on develop, the second error shows up on both develop and master regression tests. Do you know what the issue is on this toolset/platform? I am asking because Boost.Contract uses Boost.Option so it is showing the same failures. Thank you. --Lorenzo

5 7

Re: [boost] [contract] _NOEXCEPT errors in <ostream> for Clang 5.0 C++1z on Teeks Linux
by Lorenzo Caminiti 22 Nov '17

22 Nov '17

Hello Tom, On Tue, Nov 21, 2017 at 7:16 PM, Tom Kent <lists(a)teeks99.com> wrote: > On Mon, Nov 20, 2017 at 9:06 PM, Tom Kent <lists(a)teeks99.com> wrote: >> >> I was able to get to the bottom of this, I hope the libc++ builds start >> cycling normally now. >> >> > This was marked (by me!) as a clang bug - that was fixed in clang trunk >> > in January 2013. >> > I find it hard to believe that you're running a clang built from those >> > sources. >> > >> > -- Marshall >> >> It turns out I had put in a script patch the broken ubuntu header: >> >> https://github.com/teeks99/boost-cpp-docker/blob/11e6d31ca8d28dee8bbb5536f2… >> >> This was a very brittle patch, and when ubuntu fixed it upstream (just two >> months ago!) it caused some kind of conflict. I've removed the patch from my >> teeks99/boost-cpp-docker images, so the clang-3.9, -4, -5, and -6 images >> should be able to use libc++ correctly now. >> >> Thanks for all who helped me straighten this out! >> > > There was a further issue with the need for a `-lc++abi` linker option, it > has been added and the results look better now. Yes, Boost.Contract regression tests now pass on this compiler/platform. The issue was fixed. Thanks a lot. --Lorenzo

1 0

Re: [boost] Interest for Algorithmic Adjoint Differentiation (AAD) in Boost?
by Antoine Savine 22 Nov '17

22 Nov '17

I just realized that the attachment exceeds (by far) the maximum size. With apologies (this is my first post), re-posting now without the attachment. The introduction can be found at the top level of the repository, under the name AADIntro.pdf Thank you. Antoine Savine From: Antoine Savine Sent: 22 November 2017 12:38 To: 'boost(a)lists.boost.org' <boost(a)lists.boost.org> Subject: Interest for Algorithmic Adjoint Differentiation (AAD) in Boost? AAD is a hot topic in machine learning, computational finance, and, I think, other disciplines such as meteorology. Adjoint differentiation computes a large number of derivatives sensitivities for some calculation code in constant time, and operator overloading in C++ permits its semi-automatic implementation over templated code. Please see the intro attached for details. I have been working with AAD (in finance) for 5 years. I have been developing and using professional AAD libraries, I have given dedicated talks and workshops at professional conferences such as Global Derivatives and WBS, and I have been teaching AAD at the MsC in Mathematical Finance at the Copenhagen University in Denmark (Mathematics Department). Our implementation in Danske Bank obtained in 2015 the In-House System of the Year 2015 Risk award. I am planning a book on AAD. And, although that publication is biased towards finance, I have developed an independent, simple and efficient AAD engine that can be found here: tinyUrl.com/aadCentral The implementation uses the latest developments in AAD technology for maximum performance, in particular expression templates. I thought that given the wide interest for AAD, a Boost.Aad module could make sense and I was hoping that it could be based on my developments. Please could somebody let me know if there is interest, and, if so, how I should proceed? Million thanks. Kind regards, Antoine Savine

1 0

[release][poly_collection] Permission to merge to release
by Joaquin M López Muñoz 22 Nov '17

22 Nov '17

Hello, I'm asking for permission to merge the following commit chain into release: https://github.com/boostorg/poly_collection/commit/3609895bd01e5add5971345a… https://github.com/boostorg/poly_collection/commit/18b7d88df360001c2c006f02… https://github.com/boostorg/poly_collection/commit/ce7e7aac60747c6fad5e97d2… https://github.com/boostorg/poly_collection/commit/ab32df47f8811dc7f136a166… https://github.com/boostorg/poly_collection/commit/df754527917b7be013ce558f… Fixes bring compatibility with Clang 3.3 and solve a potential UB problem related to CWG 232 and detected at http://www.boost.org/development/tests/develop/developer/Marshall-UBSAN-pol… I'm waiting for Marshall-UBSAN to cycle through these but all recently updated test runners are working fine. Clang 3.3 is already verified to work by teeks99-02-dc3.3-11-Docker-64on64. Thank you, Joaquín M López Muñoz

2 2

Adding polymorphic_value to boost
by Jonathan Coe 22 Nov '17

22 Nov '17

I'd like to propose adding the class-template `polymorphic_value` to boost. `polymorphic_value` is designed to allow the compiler to correctly generate special member functions for classes with polymorphic components (It's `any` with an interface). `polymorphic_value` has been proposed for standardisation in P0201 and has advanced through the Library Evolution group in Albuquerque (Nov 5-10). https://wg21.link/p0201 A working draft of the proposal and implementation can be found at https://github.com/jbcoe/polymorphic_value I gave a presentation about polymorphic_value at C++::London here: https://skillsmatter.com/skillscasts/9539-a-polymorphic-value-type-for-c-pl… Matt Calabrese has kindly offered to be review manager. Kind regards, Jon

17 56

[release] Boost 1.66.0 Beta 1
by Daniel James 21 Nov '17

21 Nov '17

Boost release 1.66.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.66.0.beta.1/source/> The SHA256 checksums are as follows: e7b23e638e8c3a9da1512439385b04850829cea7bd56d8398677c096857d830b boost_1_66_0_b1.7z 5d0405eb73bd609ebcd54bbc96d4f1e2d97c51b96c4703706695ddd94f942d6b boost_1_66_0_b1.tar.bz2 f0f455e39bc47b2b670a17cb221687506e9a22dc478956d3d8aabb9cb835a7dc boost_1_66_0_b1.tar.gz 694c8b9e902b7981670bce166f675f3875c19326936db51aabd98d2ddfea9b45 boost_1_66_0_b1.zip For details of what's in the release, see <http://www.boost.org/users/history/version_1_66_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

2 1

icl mainainership?
by Avi Kivity 21 Nov '17

21 Nov '17

Hello, I see there are 7 pull requests outstanding against icl (including one of mine), but not activity. Joachim, are you still maintaining the library? If not, perhaps someone can step up.

3 4

Fwd: Adding polymorphic_value to boost
by THOMAS JORDAN 20 Nov '17

20 Nov '17

On 19 November 2017 at 23:41, <boost-request(a)lists.boost.org> wrote: > > Message: 12 > Date: Mon, 20 Nov 2017 01:41:10 +0200 > From: "Peter Dimov" <lists(a)pdimov.com> > To: <boost(a)lists.boost.org> > Subject: Re: [boost] Adding polymorphic_value to boost > Message-ID: <E0D82A60493A491CBFFD0E264E3917D1@pdimov5> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > Peter Bartlett wrote: > > > The only nit I had in the paper was that after all the banging on about > it > > being a value type, we are given operator bool, operator* and operator->, > > making it pointer-like again. Could operator T& and operator T const& > > work? > > Polymorphic means virtual functions, and when you have a > polymorphic_value<T> pv, where T has a virtual function `f`, you can call > `pv->f()`. With a conversion to T&, you can't call `pv.f()`. > I believe I've seen other libraries (maybe Optional) provide the helpful comment above accessors used like this to the effect that 'this accessor syntax does not imply pointer semantics.' I guess -> and * accessors would not be required if there was such as thing as overloaded dot operator.

1 0

MSVC toolset versions on VS2017
by Tom Kent 20 Nov '17

20 Nov '17

I just came across this article on feature updates for their compiler during the VS2017 lifetime, I thought the section talking about version numbers might be of interest to the boost build maintainers and boost config maintainers. The blog post can be found here: https://blogs.msdn.microsoft.com/vcblog/2017/11/15/msvc-conformance-improve… The interesting part about version numbers is three-quarters of the way down the post, under the "MSVC toolset version number increases to 14.12". The table that they have there is also illuminating: Visual Studio Version | MSVC Toolset Version | _MSC_VER --------------------------------------------------------------- VS2015 and updates 1, 2, & 3 | v140 in VS; version 14.00 | 1900 VS2017, Version 15.1 & 15.2 | v141 in VS; version 14.10 | 1910 VS2017, Version 15.3 & 15.4 | v141 in VS; version 14.11 | 1911 VS2017, Version 15.5 | v141 in VS; version 14.12 | 1912 --------------------------------------------------------------- Just wanted to give people a heads-up that this is something that may be encountered in the wild soon. Tom

2 1

[multiprecision]: 15% slowdown using -std=c++11 compiler flag
by Kim Walisch 20 Nov '17

20 Nov '17

I have been investigating a 15% performance regression in my C++ primesum program (https://github.com/kimwalisch/primesum/tree/256-bit) over the last 2 days. By lots of benchmarking I was able to identify the boost multiprecision library together with -std=c++11 (or -std=gnu++11) as the culprit for the performance regression because I have also a version of the primesum program which does not use the boost multiprecision library and in this version there is no performance regression when compiling using -std=c++11. I have tested using multiple versions of the boost multiprecision library including the latest 1.65.1. The slowdown happens on both GCC (versions: 5.4, 6.4, 7.2) and Clang (version 3.8) on x86_64 Linux. I am only using the int256_t and uint256_t types (hence cpp_int backend) and I am doing only simple integer arithmetic: +, - and *. Is this a known issue and is there a known workaround e.g. special compiler flag? I could revert to C++98 but I really don't want to do that... Thanks, Kim Walisch

2 2

[contract] _NOEXCEPT errors in <ostream> for Clang 5.0 C++1z on Teeks Linux
by Lorenzo Caminiti 20 Nov '17

20 Nov '17

Hello all, Most of Boost.Contract regression test fail for toolset clang-gnu-linux-5.0~c++1z~lc on platform teeks99-02-dc5-1z-lc-Docker-64on64 because of the following error on #include <ostream> done by Boost.Range (and sometimes by Boost.IOStreams): "clang++-5.0" -c -x c++ -Wno-c99-extensions -std=c++1z -stdlib=libc++ -isystem/usr/include/libcxxabi -O0 -g -fno-inline -Wall -g -fPIC -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTRACT_DISABLE_THREADS -DBOOST_CONTRACT_DYN_LINK -DBOOST_SYSTEM_DYN_LINK=1 -I".." -I"../libs/contract/test/function" -o "/var/boost/run/results/boost/bin.v2/libs/contract/test/function-smoke.test/clang-gnu-linux-5.0~c++1z~lc/debug/threadapi-pthread/function/smoke.o" "../libs/contract/test/function/smoke.cpp" In file included from ../libs/contract/test/function/smoke.cpp:9: In file included from ../libs/contract/test/function/../detail/oteststream.hpp:10: In file included from ../boost/iostreams/tee.hpp:18: In file included from ../boost/iostreams/detail/adapter/device_adapter.hpp:22: In file included from ../boost/iostreams/detail/call_traits.hpp:15: In file included from ../boost/iostreams/traits.hpp:38: In file included from ../boost/range/iterator_range.hpp:14: In file included from ../boost/range/iterator_range_io.hpp:32: In file included from /usr/include/c++/v1/ostream:138: In file included from /usr/include/c++/v1/ios:216: In file included from /usr/include/c++/v1/__locale:15: /usr/include/c++/v1/string:1942:14: error: expected ';' at end of declaration _NOEXCEPT ^ /usr/include/c++/v1/string:1947:9: error: expected unqualified-id _NOEXCEPT ^ /usr/include/c++/v1/__config:368:21: note: expanded from macro '_NOEXCEPT' # define _NOEXCEPT noexcept ^ 2 errors generated. Of course, Boost.Range and Boost.IOStreams show the same error on this toolset/platform independently of Boost.Contract. Any idea what the issue might be? Thanks, --Lorenzo

5 9

[operators] A modern SFINAE-based version of boost::operators?
by Beman Dawes 19 Nov '17

19 Nov '17

Peter Sommerlad, committee member and C++Now presenter who often proposes additions to fill in holes in the standard library, asked me: Are you aware of anybody who tried to provide a boost::operators style of automatically providing additional operators with a single base class that through SFINAE injects all possible operators based on the ones defined in the template parameter? This won't give you the control of the current boost::operators, but would be much easier to teach. For example struct Me : make_operators_for<Me>{ Me& operator+=(Me const&); // You get + bool operator<(Me const&) const; // You get all relops (<=> will make that obsolete) Me& operator++(); // you get postfix //etc. }; Today we have the facilities and compilers to make that happen. What do you think? Who should I ask? Anyone doing any work on operators or have any thoughts about updating boost::operators? --Beman

14 31

[python] Incorrect link
by Christian Henning 19 Nov '17

19 Nov '17

Hi all, on page http://boostorg.github.io/python/doc/html/tutorial/tutorial/embedding.html the link to http://www.python.org/doc/api/exceptionHandling.html is dead. Perhaps, it should be this link: https://docs.python.org/3/tutorial/errors.html Regards, Christian

1 0

[release] Boost 1.66.0 Beta 1 Release Candidate 2
by Daniel James 19 Nov '17

19 Nov '17

The release candidates for the 1.66.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.66.0.beta.1/source/> You need to scroll past the first release candidates to find the downloads. The SHA256 checksums are as follows: e7b23e638e8c3a9da1512439385b04850829cea7bd56d8398677c096857d830b boost_1_66_0_b1_rc2.7z 5d0405eb73bd609ebcd54bbc96d4f1e2d97c51b96c4703706695ddd94f942d6b boost_1_66_0_b1_rc2.tar.bz2 f0f455e39bc47b2b670a17cb221687506e9a22dc478956d3d8aabb9cb835a7dc boost_1_66_0_b1_rc2.tar.gz 694c8b9e902b7981670bce166f675f3875c19326936db51aabd98d2ddfea9b45 boost_1_66_0_b1_rc2.zip The in progress release notes are at: <http://www.boost.org/users/history/in_progress.html> And the documentation is at: <http://www.boost.org/doc/libs/1_66_0_beta1/> 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.

3 2

Re: [boost] Adding polymorphic_value to boost
by Tom 19 Nov '17

19 Nov '17

> Message: 10 > Date: Thu, 16 Nov 2017 02:14:30 -0700 > From: Jonathan Coe <jonathanbcoe(a)gmail.com> > To: boost(a)lists.boost.org > Cc: Matt Calabrese <calabrese(a)google.com> > Subject: [boost] Adding polymorphic_value to boost > Message-ID: > <CAAbBDD9Ck+LhQ4iUraBtBkxexVKDt167qxyfTpDQqYM9bcMqLQ(a)mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > I'd like to propose adding the class-template `polymorphic_value` to boost. > > `polymorphic_value` is designed to allow the compiler to correctly generate > special member functions for classes with polymorphic components (It's > `any` with an interface). > > `polymorphic_value` has been proposed for standardisation in P0201 and has > advanced through the Library Evolution group in Albuquerque (Nov 5-10). > https://wg21.link/p0201 > > A working draft of the proposal and implementation can be found at > https://github.com/jbcoe/polymorphic_value > > I gave a presentation about polymorphic_value at C++::London here: > https://skillsmatter.com/skillscasts/9539-a-polymorphic-value-type-for-c-pl… > > Matt Calabrese has kindly offered to be review manager. > > Kind regards, > > Jon Hi, I'd be interested in such a utility. Mathias Gaunard proposed something similar on the mailing list a long while ago, I implemented a simple version myself based on that. I have a small number of questions. Given that this is a value type, does the current approach over-expose pointer (ownership) in the interface (in essence it still appears to be a glorified smart pointer) and understate its more fundamental purpose as a regular value with dynamic type? There might be other things which can usefully be added for such a value type, for example permitting direct construction of an object of specific (derived) type, by passing the type as well as the arguments for the constructor of that type (or wrapping the arguments in some kind of in-place factory with explicit type). Something like: // Simple wrapper to enable a static type to be passed through a forwarding constructor. template <typename T> struct Type {}; // Forwarding constructor - actual type is deduced from type wrapped in (unnamed) first argument's type template <typename D, typename... Args> explicit poly_obj(Type<D>, Args&&... args); // Also could have an emplace member function template <typename D, typename... Args> void emplace(Type<D>, Args&&... args); In theory you wouldn't need to expose pointers in the interface at all? In fact, should a type-erasure library be preferred (e.g., Boost.TypeErasure or Adobe.Poly) as it provides a more general solution for manipulating polymorphic value types (though typically harder to use)? Would you be considering supporting C++98 via using the boost::move library? Regards, Tom

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[gil][test] HOWTO set up the Boost testing process for projects with extra prerequisites ?
by Stefan Seefeld 17 Nov '17

17 Nov '17

Hi, I just merged some work to GIL's `develop` branch. This notably involves improvements to the testing infrastructure. Testing GIL is a bit involved, as it requires various backend libraries (PNG, JPEG, TIFF, etc.) to be installed. While the stand-alone testing works fine (https://github.com/boostorg/gil/blob/develop/.travis.yml#L304-L306) the integrated testing will thus fail, until the testing logic is augmented by the necessary instructions to a) install the prerequisites and b) invoke the build system with the appropriate flags (https://github.com/boostorg/gil/blob/develop/io/test/Jamfile#L13-L22) Thus my question: do we have any documentation that explains how to do this ? What do I (as GIL maintainer) or any testers need to do for the integrated testing to work ? (I can't resist: all these libraries that have special requirements really shouldn't be built and tested in such a monolithic process. It's a burden to all tester, maintainers, and packagers. It would be far better to handle them more independently.) Stefan -- ...ich hab' noch einen Koffer in Berlin...

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[density] paged memory and concurrency
by Giuseppe Campana 17 Nov '17

17 Nov '17

Hi, in the last year I’ve been experimenting concurrent data structures on density, a C++11 library focused on: - Page-based memory management. - Heterogeneous and function queues. Single-threaded, mutex-ed, lock-free and spin-locking versions are available. Lock-free and spin-locking queues support any combination of single/multiple producers/consumers. - Lifo memory management, mainly to provide a safe alternative to alloca with almost the same performances. - Parametric control of the progress guarantee in concurrent algorithms. I have to do a major update to fix the known issues, so I’d like to receive any feedback before it, especially about the design. The document http://giucamp.github.io/density/doc/html/implementation.pdf explains the implementation of almost everything, though it’s quite long. Documentation: http://giucamp.github.io/density/doc/html/index.html Repository: https://github.com/giucamp/density Is there any interest on it? Giuseppe Campana.

1 0

Re: [boost] [Boost-users] Could guys help me on a boost MPI link error
by degski 16 Nov '17

16 Nov '17

On 16 November 2017 at 07:33, Renfan Luo <Renfan.Luo(a)perpetuum.com> wrote: > Thanks a lot! After changing X64 to X86 on the top of drop-down window > of IDE, the problem has been fixed. > You're welcome, degski

1 0

bjam boost build on windows - changing the path strategy (stage)
by James E. King, III 16 Nov '17

16 Nov '17

I would like to build boost into a prefix directory (.\b2.exe --prefix=C:\prefix) containing "C:\prefix\include\boost\..." and "C:\prefix\lib", just like the linux build does. On Windows it builds into ""C:\prefix\include\boost-1_66\boost\..." instead - is there a bjam control to get rid of the version in the prefix include path for header copies? - Jim

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[release] 1.66.0 fully closed for beta
by Daniel James 15 Nov '17

15 Nov '17

I've stopped updating the master branch of the super project, and will try to get the beta release out tomorrow, so there's only a little delay. You can still add your release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_66_0.q…> Thanks, -- The Boost Release Team

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Re: [boost] seeking endorsement for histogram library
by Hans Dembinski 15 Nov '17

15 Nov '17

Dear Fabian, I am CCing boost, because maybe some others want to read this as well and/or correct me. > On 15. Nov 2017, at 14:21, Fabian Bösch <boeschf(a)student.ethz.ch> wrote: > > Thanks for clarifying. While it is true that Boost.Accumulators does > this, it is for the uni-variate case only, afaik. Please correct me, if > I'm wrong. I believe you can compute a multi-dimensional mean, if you feed an appropriate Boost.Accumulator with std::valarrays. Maybe there is an easier way. > Now you have multi-variate histograms for which one would probably also > like to know the Covariance (rank-2 tensor), for example. Maybe this is > out of scope but a general solution for this would be nice. But perhaps > this would rather be addressed in another generalized accumulator > library. What do you think? I think you are right. You can compute the covariance of two variables with Boost.Accumulators: http://www.boost.org/doc/libs/1_65_0/doc/html/accumulators/user_s_guide.htm… but it does not give you a full matrix for N covariates. Maybe you could contact the maintainer of Accumulators, Eric Niebler. It is a reasonable request that would fit better into Accumulators than in Histogram. Best regards, Hans

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Re: [boost] seeking endorsement for histogram library
by Hans Dembinski 15 Nov '17

15 Nov '17

Dear Francesco, > On 13. Nov 2017, at 19:09, Francesco Guerrieri <f.guerrieri(a)gmail.com> wrote: > > Hi this proposal is of great interest to me, thanks for sharing your work with us. Which compilers/OSs are supported? I tested the code on OSX with Apple clang, and via TravisCI on several versions of gcc on Linux. The CMake build works on both OSX and Linux. I wanted to also test Windows via Appveyor, but couldn't get my CMake build script to work with msvc. I am passing compiler flags directly, which works for clang and gcc, but naturally not for msvc. Debugging this non-interactively, by committing a change to github, letting Appveyor run, seeing it breaking again..., was a pain and I stopped at some point. If an expert for Windows had a look at my CMakeLists.txt, it is probably something that could be easily fixed. Best regards, Hans

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seeking endorsement for histogram library
by Hans Dembinski 14 Nov '17

14 Nov '17

Dear Boost developers, I believe the histogram library is now ready to be presented here and I am looking for endorsement. Histogram is a C++11 header-only library that provides a safe, convenient, and fast multi-dimensional histogram for statistical analysis and visualisation. The library has a unique feature set, among it a safety guarantee that the counts in the histogram cannot overflow. It is easily customisable for power users, while providing defaults that just work for the occasional user. Meta-programming is used to provide an especially fast histogram implementation that can be used when the histogram configuration is known at compile-time. A dynamic implementation is also provided for the other case when the configuration is only known at run-time. The two implementations share a common interface, so it is easy to switch between them. Python bindings are included for the dynamic implementation. The Python interface supports Numpy arrays to greatly speed up the exchange of data between the Python and C++ side. I tested the performance of the library in benchmarks against other libraries, which have fewer features, and this library beats them in almost all cases. I am stealing the style of the rest of the email from Antony Polukhin. Library: https://github.com/HDembinski/histogram <https://github.com/HDembinski/histogram> Docs: https://htmlpreview.github.io/?https://raw.githubusercontent.com/HDembinski… <https://htmlpreview.github.io/?https://raw.githubusercontent.com/HDembinski…> Boost Library Incubator: http://blincubator.com/bi_library/histogram-2/?gform_post_id=1582 <http://blincubator.com/bi_library/histogram-2/?gform_post_id=1582> Library changes since last mail: * Support for efficient adding of multiple histograms and scaling * Support for reduce transformation * Re-design of category axis as a general mapping between unique values and bins * Re-design of the bin description an axis returns upon element access * Regular axis can accepted bijective (user-provided) transformations * Interface cleanup, refactoring, and simplification * Finished documentation Best regards, Hans

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[test] [build] best practices for looking up data files from test executables
by Stefan Seefeld 14 Nov '17

14 Nov '17

Hi there, I'm trying to write a test that needs to access a data file. As I'm surely not the first wanting to use external data in my tests, I wonder whether there are established "best practices" or idioms when using Boost.Build and Boost.Test. My first attempt was to compute the relative path using the test source's `__FILE__`, until I realized the path was invalid due to the build logic moving executables before running them. Then I considered using a command-line option to point at the data directory, but that seems quite involved when using boost::test (and BOOST_TEST_MODULE)... Any suggestions for how to approach this ? Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

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Exceptions vs Assertion for library API?
by Jonathan Biggar 13 Nov '17

13 Nov '17

Any advice in choosing between throwing an exception vs asserting for invalid uses of a library API? I'm building a small "transactional" library I'd like to contribute to boost where certain API calls are constrained to only be valid if the transaction is still "in-progress". Such calls will never succeed, and are easy for the implementation to diagnose. I'd like to have the library fail an assertion, which is far clearer to the user that the code logic is incorrect, but it bothers me that assertions are much more difficult to write unit tests for. (Is there even a concept of a test that passes if if fails to compile or fails with an assertion in the boost testing framework?) I suppose I could mangle the interface to ensure that the user has nothing to invoke the API calls in question unless the transaction is in-progress, but that generally requires a custom "lock" interface for my RAII implementation that makes the API more complex to grasp. -- Jon Biggar jon(a)biggar.org

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[release] 1.66.0 closing for beta tomorrow
by Daniel James 13 Nov '17

13 Nov '17

Hi, I'll close the master branch for the beta release tomorrow. Sorry we've been quiet about the release and that this is a bit short notice. If you haven't written your release notes yet, you can add them to: https://github.com/boostorg/website/blob/master/feed/history/boost_1_66_0.q… Use the pencil icon at the top right of the code to edit it, or you can mail your notes to me, and I'll add them. thanks, Daniel

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[release][1.66.0] Permission to merge Hana
by Louis Dionne 12 Nov '17

12 Nov '17

Hi, Being at a C++ meeting all week, I did not see the release coming and the email in time. None of the changes to Hana have been merged to master, and I'd like to get them in for the release. Can I merge them, or should I wait until after the beta? Thanks and apologies for the untimeliness, Louis -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[release][1.66.0] Permission to merge Predef.
by Rene Rivera 10 Nov '17

10 Nov '17

Some late fixes for Predef came in over the past two days: < https://github.com/boostorg/predef/commit/4a230ebe853980e27e7fb7cb36605fd6c… > < https://github.com/boostorg/predef/commit/74f88005cc2227b4f8fd4d640daae18c2… > < https://github.com/boostorg/predef/commit/5e8f5d5a4b9df640ffaeaf51e89c83e28… > Can I merge those to master for the beta? -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

2 1

Seeking endorsement for the reflection library (PFR)
by Antony Polukhin 10 Nov '17

10 Nov '17

Hello, PFR is a C++14 library that provides tuple-like methods for aggregate initializables. Library has a set of predefined operators and useful functions for everyday use. Works with user-defined types without any macro or boilerplate code. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Seeking for some endorsement, as per http://www.boost.org/development/submissions.html Library changes since last mail: * Now works on latest MSVC in C++17 mode * C++14 limitations in reflection were significantly relaxed * Removed UB (no more reinterpret casting of unrelated types!) * Thaler Benedek was approved as a review manager for the library. Boost libraries that may benefit from PFR: * Convert - for out-of-the-box conversions of user types * Hana - for using user types instead of tuples * Intrusive - for reusing unused bits in user provided types * Serialization - for out-of-the-box serialization of user types * Spirit - for putting rule results into user provided types without Phoenix or Fusion macro * Test - for outputting content of user provided types * TypeTraits - for traits like has_unique_object_representations in C++14 -- Best regards, Antony Polukhin

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Re: [boost] A GUI Library
by ha ha 09 Nov '17

09 Nov '17

If your library is only dependent on boost, not any other library like nana then it will be better in most of the beginner programmers. IF your library is pre-compiled then it will catch popularity soon, because "allegro 5" is popular for two reasons :- 1. It is very powerful and vast. 2. It is very very easy to deploy, than SDL and SFML. The first choice of the beginner programmers is always SDL but they quickly move to Allegro because of the availability of pre-built binaries. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

[devector] optimum growing/insertion policy
by Joaquin M López Muñoz 08 Nov '17

08 Nov '17

Hi, Much an worthy discussion has taken place with respect to growing and insertion policies of boost::double_ended::devector. I think I can justify what the optimum policy is when the overall goal is to minimize number of element movements. What follows is *not* a formal optimality proof, though it's my hunch one could be provided relatively easily. Assumptions * The cost of allocating new memory is negligible when compared to the cost of moving elements around (either intra-buffer or when migrating to a new buffer); so, the growing/insertion policy should focus on minimizing number of elements moved. This implies fully occupying free space before reallocation is *not* the primary goal of the growing/insertion policy. * For the purposes of our discussion, we consider an ever-growing devector without intervening erasures --erasures can be accomodated later as we will see. * Element insertion is modelled as a process where each new insertion happens at a random position within the current devector. The minimal characterization (i.e. its 1st moment in stochastic process theory terminology) is just the percentage R of insertions that happen within the right half of the devector --we call these *right insertions*; left insertions happen then with a frequency L=1-R. push_back is a right insertion, push_front a left insertion. Facts * When a right insertion arrives, if there's free back capacity the optimum insertion policy is to shift elements to the right, as this involves fewer movements than the other way around. The symmetrical applies for left insertions. * If a right insertion at position N arrives and there's no free back capacity (but there is free front capacity), we have only two options: A. Reallocate to get back free capacity. B. Shift elements to the left. The key observation here is that A is cheaper in the long run: as the scenario is one of an ever-growing sequence, reallocation will happen eventually and we can just amortize it in our analysis, so reallocating early saves us the extra movements incurred when left shifting on a right insertion, namely N - (size()-N) = 2*N - size() movements. In fact, we save more than that as insertion is done simultaneously with reallocation, hence no shifting occurs additionally to the (amortized) reallocation cost. All this analysis applies symmetrically to left insertions, of course. * The optimum growing policy is that which maximizes the probability that *both* front and back free capacities get exhausted at the same time. With our 1st moment characterization of the insertion random process, this implies that when reallocating a percentage R of the new space should be devoted to the right side, and a percentage L to the left side. Description of resulting policy * Fix the growing factor to G (this can be 1.5 or 2 or anything greater than one, the actual figure is orthogonal to the discussion). * Maintain a counter right_ of right insertions that gets incremented when a right insertion occurs and *decremented* when an erasure is issued past the middle of the devector. * Right insertions trigger right shifting except when there's no back free capacity, in which case a reallocation is performed. * Left insertions trigger left shifting except when there's no front free capacity, in which case a reallocation is performed. * Reallocation reserves space for G*size() elements: of the resulting G*size()-size() free space, a fraction right_/size() is devoted to back free capacity, the rest to front free capacity. In practice, we may want to keep some minimum space at each end as determined by some empirical threshold. And that's it. Comments welcome. Joaquín M López Muñoz

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Including a system link library for every test, but only on mingw-w64 builds?
by James E. King, III 08 Nov '17

08 Nov '17

Is BOOST_AUTO_LINK supposed to work on mingw-w64 builds with gcc? I'm guessing not since I believe this is a MSVC concept, so I am looking for a bjam recipe that will allow me to add the link library bcrypt.lib to all of the tests in a project's test directory if the build is on a windows system and not using msvc toolset. Are these any examples out there? Thanks, Jim

6 9

[type_traits] is_nothrow_move_constructible gives false positive on GCC 4.7
by Andrzej Krzemienski 08 Nov '17

08 Nov '17

Hi, It seems that boost::is_nothrow_move_constructible sometimes gives false positives on GCC 4.7. See the Git issue for details: https://github.com/boostorg/type_traits/issues/56 Regards, &rzej;

1 0

Boost.Uuid and header-only support
by James E. King, III 08 Nov '17

08 Nov '17

Hi folks, I have an open defect related to a random seed generator that's currently in boost::uuids::detail called seed_rng. The class does a fair bit more than it really needs to, and does not support Universal Windows Platform (UWP) store targets. It is otherwise quite similar to boost::random::random_device however it is a header-only implementation (in fact seed_rng has a comment about putting it into Boost.Random). I was planning on removing it and leaving randomness to Boost.Random because that's where the code really belongs, however this would introduce a new library dependency on Boost.Random for any code using boost::uuids::random_generator. So I'm curious on how important folks believe it is to maintain the header-only status of Boost.Uuid. Thanks, Jim

8 48

Preferred way to simulate system calls
by James E. King, III 06 Nov '17

06 Nov '17

I like to test every branch, and I have a class that calls open/read/close. It uses a hardcoded filename ("/dev/urandom"). It is a template in a detail namespace. What's the "boost way" when it comes to mocking these system calls? Should I make protected methods that normally call open/read/close, then subclass in a test and override them with different logic to force error paths? - Jim

3 2

[config] Rethinking feature macros?
by Peter Dimov 06 Nov '17

06 Nov '17

Now that there are standard feature-testing macros (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0096r5.html) that are being implemented by at least g++ and clang++, would it perhaps make sense for us to reevaluate our decision to provide negative macros in Boost.Config and start defining the standard feature macros instead on the compilers that don't support them? This would seem to require less maintenance, and the feature macro can be used without waiting for Boost.Config to add it. For a concrete example, let's take noexcept in function types. This is __cpp_noexcept_function_type, and is implemented by g++ 7, clang 4, clang 5 (in C++17 mode), and apparently in the latest VS2017 preview. noexcept function pointers break Boost.Bind, and to fix it, I need to add overloads for them, but only if they are implemented, otherwise the overloads would be an error. With the feature macro, I can just #ifdef __cpp_noexcept_function_type and it will immediately work on g++ and clang++ and all compilers that don't support noexcept function types will still work. Only msvc would need to be fixed in some way. With our traditional approach, I would need to request the addition of BOOST_NO_CXX17_NOEXCEPT_FUNCTION_TYPE, wait for it to be added and to be present on every compiler except the latest ones (which requires changes throughout Boost.Config), and only then be able to use #ifndef BOOST_NO_CXX17_NOEXCEPT_FUNCTION_TYPE. (Then wait for it to be merged to master before merging my changes to master.)

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[optional] Regression in develop
by Andrzej Krzemienski 06 Nov '17

06 Nov '17

Hi Everyone, Over the weekend I added changes to Boost.Optional in develop which caused regression in Boost.Beast and maybe more libraries. I would like to ask for your input as to how to best approach this. The change was: for trivial `T` use a different specialization of `optional<T>` which is trivially-copyable. For this, I need the ability to declare defaulted functions, and to detect that a given type is trivial. Boost.TypeTraits do not have `is_trivial` trait, so I compose it form `has_trivial_move` and the like. But it seems there are compilers for which Boost.config and Boost.TypeTraits report support for deleted functions/triviality detection, but where this support is buggy. The following is a test case in type_traits by Vinnie Falco: https://github.com/boostorg/type_traits/pull/52/commits/9779157a787620d1633… In addition, the deadline for changes in release 1.66 is getting nigh. I can see a couple of ways to fix this: 1. Fix Boost.Config and/or Boost.TypeTraits so that they only report support for the features in question when it is supported without bugs. But I do not know if there is enough time for this given the deadline. 2. Disable my feature on the compilers with buggy support. But I would need a help from someone who knows all the compilers and their bugs in implementation of trivial type traits so that I can put the wight `#ifdef`s. 3. Just revert my changes to Optional, which is also an option, but would also be a loss. Any input from Boost experts would be appreciated. Regards, &rzej;

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[msm] Unmerged changes in develop need review
by Peter Dimov 05 Nov '17

05 Nov '17

Boost.MSM has a number of long-unmerged changes in develop. If anyone who is familiar with MSM and cares about its state would like to review these changes and issue a recommendation on whether they, or which of them, need to be merged to master, now would be a good opportunity to do so.

1 0

[beast] Video Presentation: Designing an HTTP message container
by Vinnie Falco 05 Nov '17

05 Nov '17

Greetings! This is the video for my CppCon 2017 presentation. In this presentation I discuss designing a class for storing HTTP messages, defining some concepts along the way. The concepts are based on the ideas in Beast, but simplified for the presentation format. Anyone who is interested in learning some techniques, or getting a more advanced understanding of the Beast message container, may benefit from this video. Also, the video is entertaining on its own. Here it is: <https://www.youtube.com/watch?v=WsUnnYEKPnI> This page also contains the embedded video along with additional exposition not found in the talk: <http://www.boost.org/doc/libs/master/libs/beast/doc/html/beast/design_choic…> Thanks!

1 0

PGI
by Oliver Kowalke 05 Nov '17

05 Nov '17

Hi, does someone work on the boost-config for PGI? Running the unit-tests of boost.config fails but PGI 17.x should be C++11 compatible. Oliver

2 1

Mobile site
by Daniel James 04 Nov '17

04 Nov '17

Hi, I've been doing a little work on getting the website to work better on mobile phones. You can see it on the beta site: https://beta.boost.org There's still a lot to do, especially on the sidebar which is not really usable at the moment, so don't expect it to go live any time soon. Daniel

2 3

[parameter] RFE: perfect forwarding
by Cromwell Enage 02 Nov '17

02 Nov '17

Hi, everyone! I'm back from a long hiatus. Is anyone still interested in enhancing Boost.Parameter to handle perfect forwarding? If so, I have a patched version available at <http:/ github.com/CromwellEnage/boost-parameter-perfect_forwarding>. It includes existing header files and test source files that were modified, a few new header files and test programs, and corresponding changes to the .rst documentation files. Questions, concerns, and comments are welcome! Cromwell D. Enage

2 1

[poly_collection] Needs a 'develop' branch
by Edward Diener 02 Nov '17

02 Nov '17

The new library Boost poly_collection only has a 'master' branch. It needs to have a 'develop' branch also.

3 5

Building Quickbook docs from source code in HTML format
by Kolya Kosenko 31 Oct '17

31 Oct '17

Hello, I'm trying to build QuickBook HTML Boost library documentation from source code. I got *.docbook file, but there is no HTML files at all. For example I built stacktrace library docs: ./b2 -a libs/stacktrace/doc/ And I didn't get any HTML, only stacktrace.docbook: $ find . ./doc ./doc/gcc-5.4.0 ./doc/gcc-5.4.0/debug ./doc/gcc-5.4.0/debug/stacktrace.xml ./doc/gcc-5.4.0/debug/stacktrace.docbook ./doc/none ./doc/none/gcc-5.4.0 ./doc/none/gcc-5.4.0/debug ./doc/none/gcc-5.4.0/debug/autodoc-xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/classboost_1_1stacktrace_1_1basic__stacktrace.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/dir_3516969ce87a02a0560c741857e33749.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/dir_c8984f1860c11f62f47abb6761e46c1e.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/combine.xslt ./doc/none/gcc-5.4.0/debug/autodoc-xml/stacktrace_2stacktrace_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/classboost_1_1stacktrace_1_1frame.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/compound.xsd ./doc/none/gcc-5.4.0/debug/autodoc-xml/index.xsd ./doc/none/gcc-5.4.0/debug/autodoc-xml/stacktrace__fwd_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/index.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/stacktrace_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/namespaceboost_1_1stacktrace.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/namespaceboost_1_1stacktrace_1_1detail.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/namespaceboost.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/dir_72bdf9838375a891eaf35cbacea5f7be.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/frame__decl_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/frame_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml/safe__dump__to_8hpp.xml ./doc/none/gcc-5.4.0/debug/autodoc-xml.doxyfile ./doc/none/gcc-5.4.0/debug/autodoc-xml.xml-dir ./doc/none/gcc-5.4.0/debug/autodoc-xml.boostbook ./doc/none/gcc-5.4.0/debug/autodoc-xml.doxygen But I need something like this: http://www.boost.org/doc/libs/1_65_1/doc/html/stacktrace.html I have used quickbook install instructions for Ubuntu: http://www.boost.org/doc/libs/1_65_1/doc/html/quickbook/install.html#quickb… It looks like docbook to html conversion is required using some xsl file but I don't know how to do it and what files are used. There is some XSL files in boost/tools/boostbook/xsl folder but I don't know how to use it with b2 build. PS. I have installed xsltproc, docbook-xsl, docbook-xml packages. $ cat ~/user-config.jam using boostbook ; using xsltproc ; using boostbook : /usr/share/xml/docbook/stylesheet/nwalsh : /usr/share/xml/docbook/schema/dtd/4.2 ; using doxygen ; ----- Regards, Kolya.

2 4

[GitHelp] Getting boost stable release from GitHub after git clone
by Kostiantyn Ponomarenko 31 Oct '17

31 Oct '17

Hi, guys. I would appreciate little help in understanding what is the right way of switching to the latest stable boost release after git repository is cloned. My intention is to clone boost, because then, with new releases, I can easily update it with git and switch (checkout) to the next "current" release. PS: I like that boost uses git =). --- Kostia Kyiv, Ukraine

2 2

[contract] differentiate regressions with libc++
by Lorenzo Caminiti 31 Oct '17

31 Oct '17

Hello all, Another question on the regression tests. How am I supposed to differentiate GCC 6.0 between CrystaX-apilevel-19-armeabi-v7a-gnu-libstdc++ and CrystaX-apilevel-19-armeabi-v7a-hard-llvm-libc++? http://www.boost.org/development/tests/develop/developer/contract.html They both use the same toolset name "gcc-gnu-6", but when libc++ is used instead of libstdc++ Boost.Contract tests give these linker errors: ../boost/smart_ptr/detail/sp_counted_impl.hpp:146: error: undefined reference to 'operator delete(void*, unsigned int)' /home/cislave/.crystax/ci-boost/regression/android-19-armeabi-v7a-hard-llvm-develop/tmp/crystax-ndk-10.3.2/sources/cxx-stl/llvm-libc++/3.6/libcxx/include/sstream:189: error: undefined reference to 'operator delete(void*, unsigned int)' ../boost/iostreams/detail/streambuf/indirect_streambuf.hpp:50: error: undefined reference to 'operator delete(void*, unsigned int)' /home/cislave/.crystax/ci-boost/regression/android-19-armeabi-v7a-hard-llvm-develop/tmp/crystax-ndk-10.3.2/sources/cxx-stl/llvm-libc++/3.6/libcxx/include/sstream:740: error: undefined reference to 'operator delete(void*, unsigned int)' collect2: error: ld returned 1 exit status I wanted to mark the link errors for libc++ as expected failures while leaving libstdc++ unmarked (because there are no link errors for libstdc++). However, I don't know how to do that because the toolset name is the same "gcc-gnu-6" for both runs with libstdc++ (column 6) and with libc++ (column 10). Should the toolset names be unique instead? For example, should names like gcc-gnu-6~libstdc++ and gcc-gnu-6~libc++ have been used in this case instead of using just gcc-gnu-6 for both runs? Thank you. --Lorenzo

1 1

fuzzing boost at OSS-Fuzz
by Kostya Serebryany 31 Oct '17

31 Oct '17

Hi, I would like to invite boost developers to use OSS-Fuzz, a continuous automated fuzzing service. https://github.com/google/oss-fuzz https://opensource.googleblog.com/2017/05/oss-fuzz-five-months-later-and.ht… I've made the initial set up that fuzzes boost::regex and it found 8 bugs there, see https://svn.boost.org/trac10/ticket/12818#comment:7 3460 boost: Integer-overflow in boost::re_detail_NUMBER::basic_regex_parser... 3464 boost: Integer-overflow in boost::re_detail_NUMBER::perl_matcher... 3469 boost: ASSERT: jmp->type == syntax_element_jump 3471 boost: Stack-overflow in boost::re_detail_NUMBER::basic_regex_parser... 3472 boost: Stack-overflow in boost::re_detail_NUMBER::perl_matcher… 3478 boost: Stack-buffer-overflow in boost::re_detail_NUMBER::perl_matcher... 3479 boost: Null-dereference READ in boost::re_detail_NUMBER::basic_regex... Vinnie Falco pointed me to Jens Weller's blog post about fuzzing beast: https://www.meetingcpp.com/blog/items/fuzzing-beast.html . Jens used libFuzzer, which is one of the two fuzzing engines used by OSS-Fuzz. Adding a boost library to OSS-Fuzz will look very similar to this blog post. For those of you who are at CppCon this week: we can discuss this face to face. --kcc

1 1

property_map/compose_property_map get() return type
by Brook Milligan 31 Oct '17

31 Oct '17

I am trying to understand the logic behind the get() function for the Boost compose_property_map, which is defined in boost/property_map/compose_property_map.hpp. The document states the following: This property map is an adaptor that composes two property map. The new property map will of the same model as FPMap. I interpret these two sentences to mean that the category, value_type, and reference types of the composition will be the same as those for FPMap, while the key_type will be the same as for GPMap. Thus, I expect that get(composition,gkey) should return the same type that get(fpmap,fkey) would. However, the implement does not follow this expectation, which leaves me puzzled. The following is the relevant portion of the code: template <typename FPMap, typename GPMap> class compose_property_map { public: typedef typename boost::property_traits<FPMap>::reference reference; // return type of get(): // if (reference is not a ref) // value_type // else if (reference is const) // reference // else // const value_type& inline friend typename boost::mpl::if_< boost::mpl::not_< boost::is_reference<reference> >, value_type, typename boost::mpl::if_< boost::is_const<reference>, reference, const value_type& >::type >::type get(const compose_property_map &m, const key_type &k) { return get(m.f, get(m.g, k)); } Notice the comment and the selection of the return type. The result is always a value_type or _const_ reference, irrespective of the reference type of FPMap. Consequently, the information advertised as the reference type, which is the same as that of FPMap, is incorrect, and get() does not return a simple composition of the two property maps as described in the documentation. What is the rationale for this behavior? It seems that there must be a reason to go to the great lengths to second guess what FPMap is doing, rather than simply doing what the documentation says should occur, but I fail to see it. I look forward to any clarification. Thanks a lot. Cheers, Brook

1 0

[review] The review of Boost.DoubleEnded starts today: September 21 - September 30
by Thorsten Ottosen 31 Oct '17

31 Oct '17

Dear users and members of Boost, I'm proud to announce that the formal review of Benedek Thaler's Boost.DoubleEnded library starts today, September 21, and runs through September 30. This library is the result of Benedek's participation in Google Summer of Code 2015. The library may be downloaded from https://github.com/erenon/double_ended and the documentation may be found here: http://erenon.hu/double_ended/ Anyone is welcome to post a review and/or take part in subsequent discussions (see below for review guidelines). Introduction ------------ This is a container library that provides two containers: A. boost::devector B. boost::batch_deque Both containers provides efficient push_front and push_back operations, hence the name DoubleEnded. The boost::devector class can be seen as an extension of std::vector with efficient support for push_front (so boost::devector provides contiguous storage). In addition, it provides a customizable small buffer optimization like boost::small_vector(*). It furthermore allows for customization of the growth factor such that the user can decide if a reallocation should allocate 1.5 or 2 or whatever more memory. And finally it provides new functionality that does not exist in normal vector implementations -- this functionality allow the class to excel in performance in certain situations like serialization or transfer of data from sources that require a preallocated buffer. The boost::batch_deque is similar to std::deque, but with two important twists. Like std::deque, it provides reference stability when calling push_front/push_back. Reference stability is crucial for programs that uses intrusive containers e.g. using Boost.Intrusive (**). boost::batch_deque has the following main advantages: 1. It allows the user to specify the segment size 2. It allows for external iteration over the segments Taken together, they provide a very efficient and flexible basis for intrusive containers. Access to the segments also increases performance for tasks such as serialization. Finally, boost::batch_deque may be seen as an efficient alternative to std::vector if you want to replace a percent-wise memory overhead with a constant memory overhead and have no need for contiguous storage. Review guidelines ----------------- Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Fit as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Kind regards Thorsten, Review manager (*) boost::small_vector: https://tinyurl.com/ycslp4ot (**) http://www.boost.org/doc/libs/1_64_0/doc/html/intrusive.html

24 159

[boostbook] Building documentation with generate.consistent.ids
by Daniel James 30 Oct '17

30 Oct '17

Hi, This was originally sent to the boost-docs list, but it doesn't seem to be working, so I'm sending it here. Sorry if you receive it twice. A while ago Gregor Jasny suggested building with the generate.consistent.ids option to reduce the changes between snapshots (as many elements in the documentation had random id numbers). I've tried turning it on for the develop documentation build, and tweaked boostbook a little to take advantage of it as well. With this setting generated ids can change when the documentation is edited, but not on every build. If you have standalone documentation and you want to use this feature, you need to use '<xsl:param>generate.consistent.ids=1' in the boostbook rule in your jamfile. This mainly affects boostbook reference documentation, such as: http://www.boost.org/doc/libs/1_65_1/doc/html/boost/accumulators/as_feature… This page gets a new location in every build. With consistent ids it has the consistent, although admittedly uglier, URL: http://www.boost.org/doc/libs/develop/doc/html/boost/accumulators/as_featu_… The advantage is that this will only change when the accumulators documentation is changed (btw. the text part of that url is probably truncated more than it needs to be, I might try to fix that). Other documentation won't be affected so much, as sections usually have explicit ids (quickbook always generates them). An example where a section doesn't is: http://www.boost.org/doc/libs/1_65_1/doc/html/idp22435328-bb.html I suggest you should probably add an explicit id to something like that (I've done so in that case). Daniel

1 0

[review][DoubleEnded] Review Results
by Thorsten Ottosen 30 Oct '17

30 Oct '17

Dear users and members of Boost, I'm happy to to announce that Benedek Thaler's Boost.DoubleEnded is /conditionally/ accepted into Boost provided that it can be integrated smoothly with Boost.Container. There are several other conditions, some major and some minor which I will outline below. For now, I would like to thank everyone that participated with reviews and comments. We didn't have that many reviews, but the reviewers did spend a lot of time both on review and the following discussions. Special thanks also goes to Benedek for his hard work. It is not too often that a GSOC code ends with something of this quality. Two of the world's expert C++ container developers used phrases like "solid" and "everything looks clean and beautiful" about the implementation, "tests look very good, corner cases and all", "The reference section is very good". Congratulations, Benedek. ============== A path forward ============== Ion has most kindly accepted the idea of merging the library into Boost.Container. This consists of A. taking selected elements from batch_deque and adding them to boost::container::deque. B. putting devector into boost.container after changes have been applied to code and documentation C. back-porting the devector code to C++03 (C) does not need to happen immediately, that is, we can have a release where devector is available in a C++11 version. Ion has also most kindly agreed to help with this process. I will help write a new introduction that focuses on the main principles of devector. We also have a number of benchmarks which we can gather and use for a small section of on that topic. I'll leave it to you and Ion to work out the details. ========================== Detailed comments devector ========================== Apart from the merging with Boost.Container, the most heard complaint was about the "fat", the non-essential parts if the interface, that could be removed. This includes -- Remove the direct support for small buffer optimization form devector. When the time comes, provide small_devector similar to the way we have vector/small_vector (there is no requirement that small_devector is provided). -- remove all of the following: - all constructors that uses reserve_only_tag, - all constructors that uses unsafe_uninitialized_tag, - void unsafe_uninitialized_resize_front(size_type); - void unsafe_uninitialized_resize_back(size_type); - unsafe_push_front(...); - unsafe_push_back(...); -- add instead - constructors that uses default_init_t like boost.container - resize versions that uses default_init_t - T& unchecked_emplace_back(...) noexcept(...) - T& unchecked_emplace_front(...) noexcept(...) At some point, I hope we can upgrade default_init_t to mean no construction for all trivially copyable types. There was a wish for more symmetry in devector and so functions that break symmetry or can appear ambiguous should be removed. This means we should remove: -- capacity() There is no need for front_capacity() and back_capacity(). We could remove reserve(), but then we can't use devector with a flat_set. Reserve() should not be an alias for reserve_back() though, but controlled by the policy. We could remove resize(), but even deque has it where it means resize_back(). I totally agree it would be ideal to remove all of reserve(),resize(),capacity(),clear(), but I see no easy way we can use devector with flat containers if we remove the first and the last. Unless we start deprecating stuff in boost::deque/boost::vector and provide new consistent alternatives, we will never get a 100% satisfactory solution. At the end of the day, we need to be pragmatic, so if deprecation is not on the table, this seems the best we can do. Since we don't want two allocations implied by calling reserve_back() and reserve_front(), you can add a mechanism for doing that. That is, you can provide -- reserve( new_capacity ); -- reserve_front( new_front_capacity ) -- reserve_back( new_back_capacity ) -- reserve( new_front_capacity, new_back_capacity ) or, since reserve() is such a weird beast, simply provide -- reserve( new_capacity ); // for flat containers -- anticipate_front( new_front_elements ) -- anticipate_back( new_back_elements ) -- anticipate( new_front_elements, new_back_elements ) to get rid of the funky -- container.reserve_front( container.size() + new_front_elements ) dance. There were suggestions for shrink_back/front_to_fit, but since we are trying to remove fat, I suggest that we wait for a use-case. There were also suggestions that clear() should be amended. As the growth (or resizing policy) mandates what clear does, we need a way to escape. The minimal change that allows that is to provide -- clear( front_free_capacity ) which gives full power to the user. You may provide clear_back() as clear(0) and clear_front() as clear(c.size()+c.front_free_capacity()+c.back_free_capacity()). Ideally, clear() would have been removed entirely like capacity()/resize(), but like reserve(), it just seems like impossible when we start using it with flat containers. Other minor comments: - drop strong exception safety guarantees and do it like boost.container - prefer to make iterator a type (should be easy with reuse from boost::container::vector - allocator should not be inherted from - make clear O(1) amortized gurantees depend on growth policy - consider calling growth policy for resizing policy - make sure SFINAE works properly with constructors - make the default growth factor 2 (as we heard from Sean Parent: no factor below 2 is empirically good) - consider renaming front_free_capacity to free_front_capacity. Rationale: "front_capacity" is a concept, noun, and "free" is the adjective. Ditto for back_free_capacity. - remove size_type from growth policy and take it from the allocator - make the allocator template argument the 2nd argument - fix remaning TODO in code - documentation should not sell devector as drop-in replacement for vector, but rather stress it is not - the allocator supports needs to be improved. I guess doing it the Boost.Container way ensures that (ask Daniel James for help) - exception-safety issues pointed out by Ion - postconditions of insert/erase needs to specify behavior to front_free_capacity/back_free_capcity - use of local containers should be avoided - rotate should be avoided - delegate range move operations to those defined in Boost.Container - make sure all functions excepting non-overlapping range uses memcpy (not just memmove). This includes: - range constructor - copy-constructor - copy-assignment - range-assignment - range insert - destructor should used std::has_trivial_destructor to avoid loop in that case to make sure all compilers optimize it away (similar for erase). There is one final puzzle and that is the growth policy. I hope we can finalize that by testing Joaquin's and Ion's suggestions over the coming weeks. ============================= Detailed comments batch_deque ============================= For deque, the comments were similar, although there was far less to discuss than for devector. All agreed that one should be able to control the segment size. - stable_insert was not needed. - segment iteration was good, but should be usable with range-based for loop. The segment iterator should return a segment type if possible, and the segment should have begin(),end(),size() members. - since boost::deque already has a resize with default_init_t, that should be sufficient to provide fast serialization load for trivial types. No need for - resize_front - resize_back - unsafe_uninitialized_resize_front - unsafe_uninitialized_resize_back - reserve - shrink_to_fit() - capacity() The following are still needed for optimal code (or code that can be known not to reallocate, or for better locality in deserialization, avoiding double initialization) - free_front_capacity; - free_back_capacity; - reserve_front - reserve_back - unchecked_emplace_front - unchecked_emplace_back Boost.Container's unit-tests should be extended with those from batch_deque where it makes sense. Since segmented iteration was somewhat faster, it should be use internally where it makes sense. In particular - copy-constructor - copy-assignment - destructor As for devector, all constructor/functions that iterate over non-overlapping ranges should use memcpy. destructor should use is_trivially_destructible to ensure it is optimized away (similar for erase). ====================== Serialization comments ====================== I suggest that the default versions just do what Boost.Serialization does, perhaps just replacing resize with resize with default_init_t. That ensures it works correctly for all archive types. It also needs to use make_nvp() so the output is identical to std::vector. We will then talk to Robert about how we can take advantage of the binary archive in a correct fashion. ====================== kind regards Thorsten, review manager

8 12

PSA: Travis OS X bottleneck, <cxxstd> new Boost.Build feature
by Peter Dimov 30 Oct '17

30 Oct '17

Travis's OS X resources for open source projects seem to be insufficient, so OS X jobs are very slow and seem to be falling further and further behind. Therefore, library authors are encouraged to keep the OS X jobs to the minimum necessary. Spawning many OS X jobs takes hours (~25 minutes waiting time per job at a quick estimate). On a not entirely unrelated note, Rene Rivera has added a new feature <cxxstd> to Boost.Build that controls the C++ standard in use. So for instance, instead of the old b2 libs/mylib/test toolset=gcc cxxflags=-std=c++11 one can now use b2 libs/mylib/test toolset=gcc cxxstd=11 In addition to being more convenient, this also allows several invocations to be combined into one: b2 libs/mylib/test toolset=clang cxxstd=03,11,14,1z which can be leveraged to cut down on the number of jobs. An example of using cxxstd in .travis.yml can be seen here: https://github.com/boostorg/system/blob/develop/.travis.yml

7 13

Adapting boost::grid_graph vertex descriptors to Boost Geometry
by Brook Milligan 30 Oct '17

30 Oct '17

Generally Boost Graph vertex descriptors are opaque types with limited means of constructing them; they may be default constructed or constructed with the null_vertx() function, by dereferencing vertex iterators, calling source()/target() on an edge descriptor, or by calling the add_vertex() function. It is never expected that one will construct a vertex descriptor directly with a non-default constructor. The Boost grid_graph is similar, with the exception that vertex descriptors may additionally be constructed from a vertex index. However, a vertex descriptor for an n-dimensional grid_graph is quite naturally an n-dimensional point. Consequently, it should be possible, without breaking the abstraction, to construct one (and perhaps use one) as a point. Given that this use is not documented in any way, doing so breaks the abstraction. At least three solutions are possible: - #include <boost/geometry/geometries/adapted/boost_array.hpp> in grid_graph.hpp: boost::array<> is the implementation of the grid graph vertex descriptor, so this would immediately make vertex descriptors model Boost Geometry points. - Add a boost/graph/adapt_grid_graph_to_geometry.hpp (better name needed) file that includes the same file so that the selection is optional. - Add a boost/geometry/geometries/adapted/grid_graph.hpp file that includes the same file, again making the selection optional. Since the contents of boost/geometry/geometries/adapted generally refer to external libraries (e.g., Boost Array), the last option seems the most appropriate, although it suffers in case the vertex descriptor is changed but not the adaptor. That however applies to all the adaptors equally. Any of these solutions differs from using boost/geometry/geometries/adapted/boost_array.hpp directly in user code, because that requires unpacking the nature of the vertex descriptor and leaves open the potential for breaking changes in user code if the vertex descriptor changes. Because a vertex descriptor is opaque, breaking the abstraction seems inappropriate, even here. Thus, I suggest the following: - add boost/geometry/geometries/adapted/grid_graph.hpp which includes boost/geometry/geometries/adapted/boost_array.hpp. - add the new adaptor to the Boost Geometry documentation - add a note to the Boost Graph grid_graph documentation indicating that it is possible to adapt the vertex descriptor and use it as a point. Thoughts? Cheers, Brook

2 2

[contract] help marking regression test expected failures
by Lorenzo Caminiti 27 Oct '17

27 Oct '17

Hello all, I need some help with marking some Boost.Contract regression tests as expected failures. I don't understand why my explicit-failures-markup.xml: https://github.com/boostorg/boost/blob/develop/status/explicit-failures-mar… Doesn't math the expected failures I see on the regression report: http://www.boost.org/development/tests/develop/developer/contract.html For example, the following from explicit-failures-markup.xml (around line 887) should marked old-if_copyable test as an expected failure on msvc-11.0: ... <mark-expected-failures> <test name="old-if_copyable"/> <test name="old-if_copyable_macro"/> <toolset name="gcc-gnu-4.7.2"/> <toolset name="gcc-gnu-4.7~c++11"/> <toolset name="gcc-mngw-gnu-4.6c+"/> <toolset name="gcc-mngw-gnu-4.7c+"/> <toolset name="msvc-10.0"/> <toolset name="msvc-11.0"/> <note author="Lorenzo Caminiti"> Test fails because this complier version does not properly implement SFINAE causing incorrect errors on substituion failures for private and protected members (this seems to be fixed in GCC 4.8 and MSVC 12.0). </note> </mark-expected-failures> ... But the old-if_copyable test still shows up as a failure on the regression test report: http://www.boost.org/development/tests/develop/developer/output/teeks99-08-… Any idea what I am doing wrong? Thank you. --Lorenzo

5 19

path length too long for 64 bits builds
by Vicente J. Botet Escriba 27 Oct '17

27 Oct '17

Hi, we have an issue since we have added threadapi= . On 64 bits windows machines we are seen Austin Beer said in https://github.com/boostorg/thread/pull/188#issuecomment-339829423 "FYI, the 64-bit Windows builds are failing due the unit tests exceeding the 260 character filepath limit on Windows. Every filepath includes |\msvc-14.1\debug\address-model-64\threadapi-win32\threading-multi|. Do you know if there is an easy way to shorten this? On the 32-bit builds the filepaths don't have |\address-model-64| which is just enough to keep them under the 260 character limit so they don't fail." Is there a workaround to this issue without changing the specific part of the test files folder structure? Best, Vicente

3 3

Boost::iostreams dual-use seekable filter
by Jonathan Biggar 26 Oct '17

26 Oct '17

I see dual-use filters and seekable filters, but I can't find an example of a dual-use seekable filter. Any help digging me out of template error heck would be appreciated.

1 0

Seems like I need write-access to merge a PR
by Fernando Cacciola 25 Oct '17

25 Oct '17

Hi, It's been a lifetime since I last worked on Boost, and I'm lost as to the current procedures with the repository. I've been looking into this open ticket: https://svn.boost.org/trac10/ticket/12972 and noticed this open pull request: https://github.com/boostorg/numeric_conversion/pull/7 but even though I'm logged with my Github account, it appears I don't have write-access to merge this PR. I tried the wiki but seems to have way too much information. Can you simplify the steps needed, these days, to fix a bug on a library? specially if someone else already created a PR as in this case? TIA -- Fernando Cacciola SciSoft Consulting, Founder http://www.scisoft-consulting.com

7 17

Help wanted: Open pull request reminders
by Beman Dawes 25 Oct '17

25 Oct '17

As a library maintainer, I'd like to get periodic reminders of open pull requests for libraries I maintain and perhaps some other libraries I'm interested in. I'd like a email reminder, but others might prefer Slack or other forms of notification. A related need is for anyone to be able to find the total number of open pull requests for Boost as a whole, and perhaps get a sorted list of the per library counts. Or maybe we should just show today's count on the web site? Googling for "github open pull request reminders" shows that lots of others feel the same need. Would someone like to volunteer to review what others are doing to meet this need, and recommend an approach suitable for Boost? --Beman

9 12

Re: [boost] Boost.TR1 silently removed with 1.65?
by Guido Trentalancia 25 Oct '17

25 Oct '17

On the 9th of September 2017 19:38:43, Tim Rakowski <tim.rakowski_at_[hidden]> wrote: > Hi, > > I noticed that boost 1.65 does not contain the tr1 folder and found that > the documentation was updated accordingly: > http://www.boost.org/doc/libs/1_64_0/ contains > http://www.boost.org/doc/libs/1_64_0/libs/tr1/, while > http://www.boost.org/doc/libs/1_65_0/ has no > http://www.boost.org/doc/libs/1_65_0/libs/tr1/. > But http://www.boost.org/users/history/version_1_65_0.html > <http://www.boost.org/users/history/version_1_65_0.htmldoes> does not > mention this. > Even if it was deprecated, shouldn't this be mentioned somewhere? Googling > "site:https://lists.boost.org/Archives/boost/ 1.65 tr1" didn't yield > anything either :/ > Regards, > Tim Hello ! I am experiencing the same problem... Software packages using boost require the TR1 header files in order to build, but the TR1 header files are no longer available in version 1.65.1 ! What is going on ? Regards, Guido

5 5

[regression tests] feature request: UI integration of bjam requires clause
by Joaquin M López Muñoz 25 Oct '17

25 Oct '17

Hi, Boost regression tests as run by run.py can be explicitly disabled through two different mechanisms: 1. By marking the disabled toolsets with <mark-unusable> in status/explicit-failures-markup.xml. 2. By adding a requires clause in the corresponding Jamfile.v2 file. For instance, in Boost.PolyCollection C++11 is mandated through project : requirements [ requires cxx11_noexcept ] # used as a proxy for C++11 support ... (https://github.com/boostorg/poly_collection/blob/develop/test/Jamfile.v2 ), which results in non-C++11 toolsets being effectively disabled. The problem is that both mechanisms show very differently in the HTML report: http://www.boost.org/development/tests/develop/developer/poly_collection.ht… Toolsets disabled through markup appear grayed out wth a "n/a" legend and an (optional) link to an explanation of why the toolset doesn't work, whereas tests blocked by Jamfile's requires just show a blank column. Would it be possible to modify the regression test HTML reporting utility so that Jamfile-blocked toolsets show also as "n/a" in gray or something similar? The possibility of also adding a link to a custom explanation would be a boon, but I guess this is much harder. This would greatly increase the readability of the reports, particularly by non-savvy users who are likely to deem blank columns as just missing tests that might eventually be filled up. Many thanks, Joaquín M López Muñoz

2 2

Release Note responsibilites for maintainers
by James E. King, III 24 Oct '17

24 Oct '17

The upcoming release of 1.66.0 will be my first release in a maintainer role. How are the release notes generated and what are maintainer's responsibilities during each phase of the release cycle? Thanks, Jim

2 1

RFC.. Steering Committee Bylaws Proposal
by Rene Rivera 24 Oct '17

24 Oct '17

It has become clear to me, and some others, that the recent decisions of the Steering Committee have exposed various problems with how the Steering Committee operates. At CppCon I met with some of the Steering Committee and expressed the concerns with them. I also explained, from my experience in other organizations, how such issues are managed. The result of that is that I will be proposing the Steering Committee adopt operating Bylaws. But before formally presenting them to the Steering Committee I'd like get feedback on them <http://bit.ly/2hI22DN>[1]. The Bylaws hopefully address some key issues that I feel are at the core of the current problems: * Decisions can be made without input from interested parties. * Opaque selection of members. * No recourse by library authors to correct problems. This follows the original goals of the formation of the formation of Steering Committee of being transparent and responsive < http://bit.ly/2yoL5Ij>[2]. [1] <https://github.com/grafikrobot/other/blob/master/ bsc-bylaws-proposal/Boost%20Steering%20Committee%20Bylaws.md> [2] <https://github.com/grafikrobot/other/blob/master/ bsc-bylaws-proposal/2011-05-20%20Boost%20governance%20annotated.pdf> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

13 35

boost timer, warnings, backlog
by James E. King, III 24 Oct '17

24 Oct '17

I'm seeing a warning for use of "long long" in a lot of builds, originating in Boost.Timer. I like warning-free builds, so this is something I would like to see resolved. There's an issue in Boost Trac for it: https://svn.boost.org/trac10/ticket/12996 There's a pull request open since April for it (and 3 more going back a couple years): https://github.com/boostorg/timer/pull/4 Is this module still actively maintained? Thanks, Jim

5 6

[Outcome] WG21 papers of interest to Boost and Outcome
by Niall Douglas 24 Oct '17

24 Oct '17

This October's mailing has lots and lots of WG21 papers related to Outcome which were strongly influenced by the peer review here in May. Boost members who contributed to the Outcome v1 review in May should please take a bow and accept thanks for spurring so much discussion and debate regarding these potential future C++ features. Thank you. 1. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0323r3.pdf Utility class to represent expected object 2. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0650r1.pdf C++ Monadic interface 3. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0762r0.pdf Concerns about expected<T, E> from the Boost.Outcome peer review 4. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0779r0.pdf Proposing operator try() (with added native C++ macro functions!) 5. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0786r0.pdf SuccessOrFailure, ValuedOrError and ValuedOrNone types 6. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0824r0.pdf Summary of SG14 discussion on <system_error>: towards exception-less error handling Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

1 0

[timer][msvc] Universal-Windows advice needed
by Beman Dawes 23 Oct '17

23 Oct '17

Pull request https://github.com/boostorg/timer/pull/3 is a fix for Universal-Windows: "universal-windows: GetProcessTimes is not supported". Does anyone have a clue whether the P/R is correct and the best solution? Is the stated problem a temporary one that Microsoft will likely fix, and will it likely be a permanent limitation? Thanks, --Beman

1 0

[system] Header-only Boost.System by default ?
by Damien Buhl 23 Oct '17

23 Oct '17

Dear Boost, Is there any reason why Boost system couldn't be set to be header only by default ? Defining both macros allows it : - BOOST_SYSTEM_NO_DEPRECATED - BOOST_ERROR_CODE_HEADER_ONLY This ease, speeds up and reduces binary size greatly, that it's sad that non-aware Boost User needs to link to some dll/so/dylib of Boost.System per default. It has been in many releases of Boost, wouldn't it be good to set it to be the default for a next release ? Cheers, -- Damien Buhl Software Developer +33 6 77 43 10 05

10 25

[BoostBook] how to automatically test code examples?
by Hans Dembinski 19 Oct '17

19 Oct '17

Hi everyone, I am using BoostBook to prepare the documentation for the proposed histogram library https://github.com/HDembinski/histogram I have written a good deal of the documentation already, and it compiles fine with bjam (thanks to Klemens who showed me how). It says in the BoostBook documentation http://www.boost.org/doc/libs/1_65_1/doc/html/boostbook.html "The BoostBook format allows testcases to be generated by weaving together program fragments from example programs in the documentation. This capability is integrated with testsuite generation so that example programs are normal tests in BoostBook." That's awesome, I would love to use this feature, but the documentation is not explaining how to actually do that. I found the element "testsuite" which probably does what I want. I went on to scan the Boost repository for this BoostBook element, but couldn't find an example to copy from. Could someone help me out? How do I modify my BoostBook and Jam files to generate tests out of the code examples in the documentation? Best regards, Hans

6 14

[msvc] #warning preprocessor directive
by Beman Dawes 17 Oct '17

17 Oct '17

I find it very irritating that VC++ does not support #warning, and have opened a feature request: https://visualstudio.uservoice.com/forums/121579-visual-studio?query=Add%20… The last time #warning was suggested it was rejected because not enough people voted for it. So please consider upvoting it on the above link. The lack of #warning affects Boost libraries in that developers avoid otherwise useful warnings because of the hassle for using an extension not supported by VC++. --Beman

6 20

Merged #149, "Encode architecture and address model in versioned layout names"
by Peter Dimov 17 Oct '17

17 Oct '17

I've just merged https://github.com/boostorg/boost/pull/149, "Encode architecture and address model in versioned layout names", into the develop branch. Let's see how this goes. Welcome to 2005. :-)

6 10

How to build boost on windows with Clang/LLVM
by degski 17 Oct '17

17 Oct '17

With the latest snapshot builds of clang, thin LTO is supported on Windows. This thin LTO gives very interesting (speed) results. I would therefore like to start to build boost with clang and no longer with msvc. I have msvc 15.4 installed (the latest incarnation). I made a project-config.jam: =============start=============== import option ; using clang : 6.0 : clang++.exe : <cxxflags>-fmacro-backtrace-limit=0 <cxxflags>-Wno-invalid-token-paste <compileflags>-fmsc-version=1911 <linkflags>-fuse-ld=lld <linkflags>-flto=thin ; option.set keep-going : false ; ==============end=============== I call: bjam -a -d+2 cxxflags="-O0" "-sZLIB_SOURCE=%HOME%\zlib-1.2.8" "-sBZIP2_SOURCE=%HOME%\bzip2-1.0.6" variant=debug instruction-set=haswell threading=multi link=static runtime-link=static --prefix=%PREFIX% --build-dir=c:\boost-build address-model=64 architecture=x86 toolset=msvc --without-python --without-mpi --disable-filesystem2 install This does not work. What is the proper way to compile boost on windows using clang++.exe or clang-cl.exe for use with VS2017. degski -- "*Ihre sogenannte Religion wirkt bloß wie ein Opiat reizend, betäubend, Schmerzen aus Schwäche stillend.*" - Novalis 1798

3 7

Looking for a task to contribute to boost
by vivek pandya 17 Oct '17

17 Oct '17

Hello Boost Developers, I am Vivek. I contribute small patches to LLVM project. I wanted to work for boost open source project to enhance my C++ knowledge. Could someone suggest some project to me? I will be able to complete task suitable for Google Summer of Code with help and guidance form community. Please also suggest required assignments as I am not a frequent user of Boost libraries. Thanks, Vivek

3 2

Recommend dropping test coverage on msvc-7.1 and msvc-8.0
by James E. King, III 16 Oct '17

16 Oct '17

MSVC 7.1 and MSVC 8.0 are currently listed as "tested" in the Boost 1.65.1 release notes however there are a lot of projects that do not seem to support them well, if at all: http://www.boost.org/development/tests/master/developer/issues.html <http://www.boost.org/development/tests/develop/developer/issues.html> It looks like a large number of libraries will no longer build properly against them based on this report. I'm not sure what the procedure is to come to an agreement to drop a compiler in a release, but it looks like we should consider dropping msvc-7.1 and msvc-8.0. These are very old compilers for Windows development. Dropping them would also allow folks to more easily focus on failures in this report to make sure a release is as clean as possible and simplify the test matrix a little bit. Appveyor only supports back to Visual Studio 2010 at this point, so our ability to get pre-commit checks on compilers before msvc-10.0 is solely based on maintainer effort. I suspect this effort is no longer justified based on the age of the compilers. Thanks - Jim

13 31

Bjam broken on windows with VS2017?
by degski 16 Oct '17

16 Oct '17

My lappie has vs2017 installed, latest (15.4) version, from some days ago. I did the following: 1. Put a clean copy of the boost 1.65.1 source in c: root. 2. issue 'bootstrap.bat' in c:\boost_1_65_1\ (ordinary prompt, no vs thingy). This creates a project-config.jam msvc file. 3. Copied (overwrote project-config.jam) the below contents as project-config.jam to c:\boost_1_65_1\ =======start======= import option ; using clang : 6.0 : "C:\\Program Files\\LLVM\\bin\\clang++.exe" : <compileflags>-fmsc-version=1911 <compileflags>-DBOOST_USE_WINAPI_VERSION=0x1000 <compileflags>-DBOOST_USE_WINDOWS_H=1 <compileflags>-D_WIN32_WINNT=0x1000 <compileflags>-DNOMINMAX <ranlib>"C:\\Program Files\\LLVM\\bin\\llvm-ranlib.exe" <archiver>"C:\\Program Files\\LLVM\\bin\\llvm-ar.exe" <linkflags>-fuse-ld=lld <linkflags>-flto=thin ; option.set keep-going : false ; =======end======== 4. issue 'bjam -d0 --clean' The script of that, and the result is below: Microsoft Windows [Version 10.0.15063] (c) 2017 Microsoft Corporation. All rights reserved. C:\Users\User>cd \ C:\>cd boost_1_65_1 C:\boost_1_65_1>bootstrap.bat Building Boost.Build engine Bootstrapping is done. To build, run: .\b2 To adjust configuration, edit 'project-config.jam'. Further information: - Command line help: .\b2 --help - Getting started guide: http://boost.org/more/getting_started/windows.html - Boost.Build documentation: http://www.boost.org/build/doc/html/index.html C:\boost_1_65_1>bjam -d0 --clean 'C:/Program' is not recognized as an internal or external command, operable program or batch file. etc.. etc... the rest is history? Any ideas? degski

2 3

'Fibre safe optimisations' with gcc/clang (non Windows target) and Boost.Context
by james 15 Oct '17

15 Oct '17

I was considering whether I could/should build an actor system on Rust rather than C++, since it would be an interesting exercise for me. And then I found this article: https://www.reddit.com/r/rust/comments/56wgzq/status_of_coroutines/ In particular: > we noticed that the Rust stdlib is actually using TLS (!) to implement exceptions It seems to me that in practice other compilers might use some sort of thread-local hook for exceptions, whether it is TLS or something lower-level that supports TLS. And that the issue is whether the compiler will assume that the address of the TLS (or thread information block etc) is volatile, or can be cached in a stack frame or register across calls. It seems to me that any such caching of an address might cause difficulty, not just in Rust but also other languages. Microsoft's compiler explicitly has a switch for 'fibre safe optimisations' that disables such caching. The worry I have is code like this: void foo() { try { A() } catch (...) {} B(); // Can switch the context to another underlying OS thread try { C() } catch (...) {} } I am concerned that information about exception handling that was acquired for the first try block, might be retained in the frame and reused in the second try block. and the information might be captured in the frame and/or registers that get saved in the context, but in an arbitrary way. I suspect that access to explicit ABI TLS or C++ thread local is also impacted, although it might be easier to avoid. I guess its not a complete show-stopper if we ensure that fibres never migrate between OS threads, but that is somewhat inconvenient. So - is this actually a Rustc specific issue?

1 0

printf official specs or docs, ISO C99, and C++
by James E. King, III 14 Oct '17

14 Oct '17

I found https://svn.boost.org/trac10/ticket/10541 today and my guess is Boost.Format hasn't been updated to support the ISO C99 extensions, or the Microsoft type formats. Before any work is done on this, I'm looking for any official C++ documentation related to printf support requirements. For example the compatibility section in http://www.cplusplus.com/reference/cstdio/printf/ indicates certain language levels have requirements. Thanks, Jim

3 3

[build] Building library with vc++ 64-bit does not find vcvarsall.bat
by Edward Diener 13 Oct '17

13 Oct '17

If I build any library with any version vc++ 64-bit compiler, by using address-model=64, the vcvarsall.bat is looked for at, for example with msvc-14.0, C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/vcvarsall.bat and is not found. Naturally this leads to basic compilation failures. The path for vcvarsall.bat for msvc-14.0 is C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/vcvarsall.bat instead. All versions of vc++ follow this path structure for vcvarsall.bat Building with any version of vc++ 32-bit, by not specifying the address-model, works correctly.

3 4

1.65.1 as modular packages on Conan.io
by Rene Rivera 13 Oct '17

13 Oct '17

Following on with the announcement before CppCon of the 1.64.0 modular packages here we are with more. I'm pleased to announce that the 1.65.1 Boost C++ Libraries are now available individually using the Conan package manager. There's even some improvements for the 1.64.0 package also :-) Find out more from the Bincrafters post here <http://bit.ly/2g6VEpp>[1]. For help using the packages you can bug the Bincrafters team in the #Conan CppLan Slack channel <http://bit.ly/2ykeqC0>[2]. Conan is a C/C++ (and more) package manager that supports an open ended set of build system and tool integrations including: VisualStudio, Xcode, CLion, Ninja, QMake, Premake, and yes even CMake <http://bit.ly/2xzhpbg>[3]. [1] <https://bincrafters.github.io/2017/10/13/Conan-Packages-Boost-1-65-1/> [2] <https://cpplang.now.sh/> [3] <http://docs.conan.io/en/latest/integrations.html> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

1 0

Maintainers: Adding Coverity Scan to your library
by James E. King, III 12 Oct '17

12 Oct '17

I have completed the work necessary to add Coverity Scan to Boost.Uuid and wanted to share the steps involved. This work can be carried into other libraries fairly easily. 1. Go to Coverity Scan: https://scan.coverity.com/ 2. Sign up/in with your Github account. 3. Create a project for your boostorg/library. It will take about 24 hours for them to activate your account so that you can use the results browser. To run a coverity scan manually: 1. Check out your project master (or whatever branch you want to scan). 2. cd into BOOST_ROOT (where "libs/" is located) 3. Run the libs/uuid/covscan.sh script with the following environment variables set: A. COVERITY_SCAN_TOKEN: the project token in coverity scan B. COVERITY_SCAN_NOTIFICATION_EMAIL: your email C. SELF: your library name, for example SELF=uuid for Boost.Uuid 4. You will need to clean up some cruft it leaves behind as the script is designed for Travis CI - just a couple directories starting with "cov" and a tar.xz file. To integrate coverity scans for every pull request or push into master with Travis CI: 1. Make sure you have Travis CI set up properly to build your project. 2. Copy the Coverity Scan stanza from libs/uuid/.travis.yml into your .travis.yml file. Note that the Boost.Uuid travis configuration now uses jobs instead of matrix, as jobs allow for conditions. I would encourage you to convert your .travis.yml to use jobs as well. 3. The next pull request into master, or the next push into master, will trigger a build, and any build for master will run covscan.sh and upload the data. You can add component regular expressions to ignore/omit other boost library errors if you wish. Here are the results for Boost.Uuid. I have not excluded other components yet: https://scan.coverity.com/projects/boostorg-uuid Initially I saw a flurry of "unhandled exception" items which I dismissed as intentional (i.e. I want the test to segfault if an unexpected exception is thrown so that I can debug it), and that will likely be a common practice for test files, but should not be for implementations. I also caution folks against marking something as a false positive. Approach it with the mindset of, "it must be a fault of the library" before jumping to, "it must be a fault in Coverity" and really convince yourself it is not a code issue. Even if you do not have travis integration in your library, running a manual scan will help you improve the quality of your library, so I recommend everyone at least do that much. - Jim

5 5

Asciidoc, an alternative for documentation
by Peter Dimov 12 Oct '17

12 Oct '17

I've been experimenting with Asciidoc-based documentation, using Boost.Assert as my guinea pig. The good thing about Asciidoc is that Github shows a preview and you can edit it directly on github.com. This is how the source looks there: https://github.com/boostorg/assert/blob/feature/asciidoc/doc/index.adoc https://github.com/boostorg/assert/blob/feature/asciidoc/doc/assert.adoc https://github.com/boostorg/assert/blob/feature/asciidoc/doc/current_functi… This is how the generated HTML documentation looks, using the default stylesheet, without any customizations on my part: https://rawgit.com/boostorg/assert/feature/asciidoc/doc/html/assert.html And this is how the generated PDF looks: http://pdimov.com/tmp/assert.pdf The tool that produces these is Asciidoctor, http://asciidoctor.org/ .

13 34

Boost.Format Library Maintenance
by James E. King, III 12 Oct '17

12 Oct '17

Currently the Boost.Format library is being maintained by the CMT. I would like to petition for that responsibility and lighten their case load further. I recently assumed maintenance for Boost.Uuid, and I have added Universal Windows Platform support to Boost.WinAPI and Boost.Predef so that folks will have an easier time making Windows Store compatible apps. I have also been working on a change that will add UWP support to Boost.Random and turn it into a header-only library, and expect to submit that in the next few days. I would like to shore up the CI environment for Boost.Format and groom the backlog in trac and on github, and get all the open issues resolved. Thanks for your consideration, Jim King

3 3

[Build] How to build libboost_lzma?
by degski 12 Oct '17

12 Oct '17

Up till now I have built libboost_zlib and libboost_bzip2 by setting ZLIB_SOURCE and BZIP2_SOURCE variables to their respective source directories on the bjam command-line and the libraries get built without fail. I gather (from the bjam output) their is now support for lzma, which I would like to use. I've tried a similar (did not find a doc) approach with LZMA by feeding "-sLZMA_SOURCE=c:\xz-5.2.3" (from https://tukaani.org/xz/xz-5.2.3.tar.gz) to bjam. This does not work. How do I make bjam build libboost_lzma? Thanks in advance. degski -- "*Ihre sogenannte Religion wirkt bloß wie ein Opiat reizend, betäubend, Schmerzen aus Schwäche stillend.*" - Novalis 1798

1 1

Boost Serialization: Serializing large objects
by Adlai Shawareb 12 Oct '17

12 Oct '17

We are trying to text serialize a 700 MB object. We are getting an archive_exception: input stream error. This is on a 32-bit QNX system. * Is there a limit to the size of the object that can be serialized? * Is there anything we can do to fix or work around this? Here is the code we are using: std::stringstream ss_; boost::archive::text_oarchive oa(ss_, boost::archive::no_header); oa << &object; Adlai

4 11

interest in a stateful pointer library?
by Hans Dembinski 11 Oct '17

11 Oct '17

Hi everyone, I wrote a variant of std::unique_ptr, called tagged_ptr, which allows safe read/write access to a customisable number of bits in the pointer variable. You can find the library on github: https://github.com/HDembinski/stateful_pointer You can use those bits to store extra state in the pointer variable at no extra space cost. I did some benchmarks to show that the computational overhead required for the bit manipulation is also negligible. One needs little imagination to find good use for those bits. As a proof of principle, I wrote an STL compatible string class which has the size of const char*, but can store up to 7 ASCII characters (on a 64 bit system) without allocating any memory on the heap (aka small string optimisation). The string class is also included in the library. To make this work, I use one of the bits in the pointer variable to recognise whether the variable should be interpreted as a pointer or as a char array. The Stateful Pointer library is C++11, header-only, and AFAIK platform-independent (in theory, this has not been tested so far). To create pointers which allow one to use a certain number of bits for other purposes, I rely on Boost.Align to allocate aligned memory. How does it work? Aligned memory, as the name implies, does not point to any address in memory, only certain addresses are allowed. For example, a two-byte aligned memory block can only have an even address. Therefore the lowest bit in the address is always zero. Since the bit is guaranteed to be zero, we can use it to store something else and mask it to zero whenever we need to dereference the pointer. I think this is a generally useful class to have in Boost, so is there some interest in polishing it up in a review process? Best regards, Hans

7 18

Master Regression Tests Failing
by Tom Kent 11 Oct '17

11 Oct '17

It appears that we haven't had any successful runs of the regression tests on master since last Friday afternoon. Looking at some logs, I'm seeing output like below. Any ideas? Tom notice: [lzma] Condition /var/boost/run/boost_bb/src/build/feature.jam:140: in feature.feature from module feature error: feature already defined: error: in feature declaration: error: feature "threadapi" : "pthread" "win32" : "propagated" /var/boost/run/boost_root/libs/thread/build/Jamfile.v2:151: in modules.load from module Jamfile</var/boost/run/boost_roo t/libs/thread/build> /var/boost/run/boost_bb/src/build/project.jam:325: in load-jamfile from module project /var/boost/run/boost_bb/src/build/project.jam:64: in load from module project /var/boost/run/boost_bb/src/build/project.jam:89: in load-used-projects from module project /var/boost/run/boost_bb/src/build/project.jam:75: in load from module project /var/boost/run/boost_bb/src/build/project.jam:89: in load-used-projects from module project /var/boost/run/boost_bb/src/build/project.jam:75: in load from module project /var/boost/run/boost_bb/src/build/project.jam:113: in load-parent from module project /var/boost/run/boost_bb/src/build/project.jam:464: in initialize from module project /var/boost/run/boost_bb/src/build/project.jam:306: in load-jamfile from module project /var/boost/run/boost_bb/src/build/project.jam:64: in load from module project /var/boost/run/boost_bb/src/build/project.jam:145: in project.find from module project /var/boost/run/boost_bb/src/build-system.jam:535: in load from module build-system /var/boost/run/boost_bb/src/kernel/modules.jam:295: in import from module modules /var/boost/run/boost_bb/src/kernel/bootstrap.jam:139: in boost-build from module /var/boost/run/boost_regression/boost-build.jam:57: in module scope from module # Searching for "process_jam_log" in "/var/boost/run/boost_regression/stage/bin"... Traceback (most recent call last): File "run.py", line 71, in <module> runner(root) File "/var/boost/run/boost_regression_src/regression.py", line 287, in __init__ self.main() File "/var/boost/run/boost_regression_src/regression.py", line 624, in main getattr(self,action_m)() File "/var/boost/run/boost_regression_src/regression.py", line 581, in command_regression self.command_setup() File "/var/boost/run/boost_regression_src/regression.py", line 352, in command_setup self.build_if_needed(self.process_jam_log,self.pjl_toolset) File "/var/boost/run/boost_regression_src/regression.py", line 715, in build_if_needed tool[ 'build_path' ] = self.tool_path( tool ) File "/var/boost/run/boost_regression_src/regression.py", line 740, in tool_path , '\n'.join( [ name_or_spec[ 'path' ], build_dir ] ) Exception: Cannot find "process_jam_log" in any of the following locations: /var/boost/run/boost_regression/stage/bin/process_jam_log /var/boost/run/boost_regression/stage/bin

9 19

[ANN] Boost.UI - a new C++ GUI library
by Kolya Kosenko 10 Oct '17

10 Oct '17

Hello, Here is my C++ GUI library based on Boost, it - is cross-platform - uses native system-provided widgets - has STL-like and Boost-like API - compatible with other Boost libraries - supports modern C++11/14/17 features Currently supported modules: - Graphics - Widgets * Command widgets * Data input-output widgets + Date and time pickers + Strings container widgets + Text widgets * Informational widgets + Logging * Containers + Alerts + Notifications + Prompts - Layouts - Events - Audio - Coordinates - Localization - Thread support - Helpers Documentation (and "Hello, World!" application source code): https://kosenko.github.io/boost.ui/ Source code: https://github.com/kosenko/ui Beman's challenge: https://github.com/kosenko/ui/blob/master/example/cpp11/beman.cpp Re-implemented GUI examples from Bjarne Stroustrup's book: https://github.com/kosenko/ui/blob/master/example/cpp11/stroustrup.cpp Other examples: https://github.com/kosenko/ui/tree/master/example What do you think? Regards, Kolya Kosenko.

11 21

Boost Trac, random, No-Maintainer?
by James E. King, III 10 Oct '17

10 Oct '17

I filed 3 defects into Boost Trac for Boost.Random based on work I just did on adding CI integration, and the maintainer that Trac assigned to these new items was "No-Maintainer". That seems incorrect? The backlog in trac for random also has "No-Maintainer" assigned to all the items. For folks who like (potential) compiler optimization bugs: https://svn.boost.org/trac10/ticket/13247 - Jim

10 37

Boost.HTTPKit, a new library from the makers of Beast!
by Vinnie Falco 10 Oct '17

10 Oct '17

During the formal review of Beast the desire was expressed to have parsing and serialization available independently of Asio. Unfortunately the obstacles to this are the concrete functions and types required for interoperability with the buffer sequence concepts defined in Asio. I have drawn up a solution to this problem which involves creating two brand new libraries. The first new library is called Boost.Buffers, and I described it partially in an earlier list posting. This library will contain copies of just the header files from Asio needed to implement the buffer sequence concepts. A preprocessor switch will allow users of Boost.Buffers to decide whether to use the copies of the headers, or to just include the Asio headers directly: <https://github.com/vinniefalco/buffers/blob/30ef7031ec0909972a720c0cdd8d6c6…> If an author wants to develop a library which uses just the buffer sequence concepts from Asio, then instead of writing: #include <boost/asio/buffer.hpp> they will instead write: #include <boost/buffers/asio.hpp> in header files, and in their build scripts set: #define BOOST_NET_BUFFER_NO_ASIO 1 This way, their tests and example programs will use the copies of the asio headers found in the Boost.Buffers libraries and everything will work. Boost.Asio will not be a dependency. However, if a consumer of that library wants to also use Boost.Asio, they can do so by just not setting the macro in their build scripts (or explicitly setting it to 0). Now that we have a way to write a library that uses Asio buffer concepts without depending on all of Asio, we can move the Beast dynamic buffer implementations and buffer adapters into the Boost.Buffers library. Boost.Buffers will contain these public includes: Boost.Buffers <boost/buffers.hpp> <boost/buffers/asio.hpp> boost::asio::const_buffer boost::asio::const_buffers_1 boost::asio::mutable_buffer boost::asio::mutable_buffers_1 boost::asio::buffer_copy boost::asio::buffer_size boost::asio::buffer_cast boost::asio:is_const_buffer_sequence boost::asio:is_mutable_buffer_sequence <boost/buffers/buffers_adapter.hpp> <boost/buffers/buffers_cat.hpp> <boost/buffers/buffers_prefix.hpp> <boost/buffers/buffers_suffix.hpp> <boost/buffers/buffers_to_string.hpp> <boost/buffers/flat_buffer.hpp> <boost/buffers/flat_static_buffer.hpp> <boost/buffers/multi_buffer.hpp> <boost/buffers/ostream.hpp> <boost/buffers/read_size.hpp> <boost/buffers/static_buffer.hpp> Boost.Buffers would have dependencies on these Boost libraries: Array Assert Config Core Exception Intrusive StaticAssert ThrowException TypeTraits Beast will then be modified to take a dependency on Boost.Buffers to have access to all the buffer adapters and dynamic buffer implementations. Now that we have a new library which offers Asio buffer concepts and Beast's collection of useful dynamic buffers and buffer adapters, we can extract the HTTP parsing and serialization algorithms from Beast to form a new library: Boost.HTTPKit will contain these public includes: Boost.HTTPKit <boost/http/basic_file_body.hpp> <boost/http/basic_dynamic_body.hpp> <boost/http/basic_parser.hpp> <boost/http/buffer_body.hpp> <boost/http/chunk_encode.hpp> <boost/http/dynamic_body.hpp> <boost/http/empty_body.hpp> <boost/http/parse_error.hpp> <boost/http/field.hpp> <boost/http/fields.hpp> <boost/http/message.hpp> <boost/http/parser.hpp> <boost/http/rfc7230.hpp> <boost/http/serializer.hpp> <boost/http/span_body.hpp> <boost/http/status.hpp> <boost/http/string_body.hpp> <boost/http/string_param.hpp> <boost/http/type_traits.hpp> <boost/http/vector_body.hpp> <boost/http/verb.hpp> Boost.HTTPKit would have dependencies on these Boost libraries: Array Assert Config Core Exception Intrusive StaticAssert ThrowException TypeTraits This new library provides serialization and parsing of HTTP/1 messages to and from Asio buffer sequences, without requiring the full Boost.Asio dependency. The library also provides Beast's universal HTTP message container. Beast will be modified to take an additional dependency on Boost.HTTPKit. This solution satisfies long-stated needs of users to have HTTP parsing and serialization without Boost.Asio. However, there is one problem and that is the documentation. All of Beast's documentation related to buffer-oriented parsing and serialization, message containers, Body types, Fields concept, buffer sequences, and dynamic buffers will now be moved into two other libraries. This leaves the Beast documentation objectively worse off for users, as it is impossible to cross-link to other library documentation from inside a Javadoc comment extracted by Doxygen. I would like to hear ideas for how to smooth this out. Questions: How does the community feel about: * Boost.Buffers as a solution to accessing buffer concepts without Asio? * Boost.Buffers offering Beast's buffer sequence adapters and dynamic buffers? * Boost.HTTPKit depending on Boost.Buffers? * Boost.HTTPKit offering serialization and parsing without Asio? Any feedback is appreciated Thanks

3 5

[outcome v2] Proposed second review dates?
by Niall Douglas 10 Oct '17

10 Oct '17

Dear all, Now that the DoubleEnded review has finished, can I poll for preferred dates for a second Outcome review? Options: 1. Friday 1st December until Monday 11th December? 2. Friday 19th January until Monday 29th January? The reason for the delay is that the documentation writers are committed to other stuff until mid-November, plus there is the US Thanksgiving. Other than documentation, the library is ready to go at https://github.com/ned14/boost-outcome. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

3 6

[contract] Differential Sandia's regression tests for C++11, C++14, etc.
by Lorenzo Caminiti 09 Oct '17

09 Oct '17

Hello all, On the regression test site: http://www.boost.org/development/tests/develop/developer/contract.html How do I differentiate between the following? Sandia-clang-4.0-c++11 Sandia-clang-4.0-c++14 Sandia-clang-4.0 They all have the same toolset name clang-gnu-4.0.1 but they have different compiler options (C++11, C++14, original C++ standard). My tests are expected to fail only on Sandia-clang-4.0 but not on the first 2... I need different toolset names to selectively mark the failure expected in expected-failure-markup.xml: <mark-unusable> <toolset name="WHAT_SHALL_I_PUT_HERE?"/> <note author="Lorenzo Caminiti"> Most tests use C++11 lambda functions and variadic macros (even if technically the library itself does not require C++11). </note> </mark-unusable> Other toolset using ...~c++11, ...~c++1y prefixes for this, but Sandia does not. Thanks a lot. --Lorenzo

1 0

Need help >> Boost's managed_shared_memory usage in between two processes (C and C++)
by vijay sharma 09 Oct '17

09 Oct '17

Hi, I am having a Design/Implementation issue with Boost managed_shared_memory. Let me describe it: -------------------- Problem ------------------------- I am having two processes (i) Writer (ii) Reader Here Writer is a c++ executable which is using boost to write in shared memory. Code snapshot for writing method: shm_controller.reset(new boost::interprocess::managed_shared_memory( boost::interprocess::open_or_create, shmName, size));void * addr = shm_controller->allocate(size) ; shm_controller ->deallocate(addr); Once I have addr pointer, I am using memcpy to write in SHM. On other hand I am having Reader, which is C executable. They both are communicating via message passing application. I wrote Reader code in such way: Writer is passing address, which is stored in "addr" (from above code snapshot) to Reader. Once reader receive the address and size, I am using memcpy to write SHM data in Reader's local variable. Note1:- (This reader is not using any boost shm API, as it's C application ) Note2:- I validated address is same on Writer and reader (after communication). But reader's memcpy to read shm data is leading crash in my executable (reader). ------------------------------------------------------------- I need help in : 1) Can we use boost::interprocess::managed_shared_memory in C ?? 2) Is there any implementation problem in above section. (can't a reader access shm of writer via pointer) 3) Is there a way to solve this C and C++ limitation like any wrapper implementation etc. Please provide me any kind of help or pointers on this issue, as I am stuck with this and need to resolve it ASAP. Thanks, sharmavijay1991(a)gmail.com

2 3

Appveyor setup for msvc-14.1 toolset
by Edward Diener 09 Oct '17

09 Oct '17

I have added an Appveyor test to some Boost libraries, but if I specify toolset=msvc-9.0,msvc-10.0,msvc-11.0,msvc-12.0,msvc-14.0,msvc-14.1 on the b2 test script command line the run fails when it gets to 14.1, due to not finding 'cl', but succeeds for the others. What is the magical Appveyor incantation to test the latest VC++ ? I would like to avoid the environment/matrix gunk I see in other appveyor.yml files, but if it is the only way to get msvc-14.1 tests with Appveyor I will use it.

3 3

[review] The review period of Boost.DoubleEnded has ended -- thanks to all involved
by Thorsten Ottosen 09 Oct '17

09 Oct '17

Dear users and members of Boost, We are now done with the review of Benedek Thaler's Boost.DoubleEnded library. Many thanks to all those involved in discussions and reviews. It will take me some time to digest all the feedback and get back with the review results. kind regards Thorsten, review manager -- Best regards, Thorsten Jørgen Ottosen, Ph.D. Director of Research +45 23308797 Dezide (www.dezide.com)

1 0

Boost.Http parser documentation ready (feedback welcome)
by Vinícius dos Santos Oliveira 09 Oct '17

09 Oct '17

Hi, first of all, do not confuse this “Boost.Http” library with the one who was rejected in the Boost review. I've received financing[1] from Boost to write an HTTP parser and here it is, just a parser. The documentation has 4 tutorials. You may have special interest in the “tutorial #4: implementing Boost.Beast parser interface” where I answer why you don't want to use Boost.Beast parser. https://vinipsmaker.github.io/asiohttpserver/ Feedback welcome. [1] https://gist.github.com/vinipsmaker/4998ccfacb971a0dc1bd -- Vinícius dos Santos Oliveira https://vinipsmaker.github.io/

1 0

GITHUB - How does one add another maintainer to a repo
by Robert Ramey 08 Oct '17

08 Oct '17

I'm maintainer of the boost serialization library. Is there a simple way to give update permission to other persons? What is it. Ideally I'd like to do it at the branch level. I've looked through the GitHub help, and as usual, I'm mistified. Robert Ramey

2 2

[thread][build] develop terminally broken?
by John Maddock 07 Oct '17

07 Oct '17

All CI tests are currently failing with: ./b2 headers /home/travis/build/boostorg/boost-root/tools/build/src/build/feature.jam:140: in feature from module feature error: feature already defined: error: in feature declaration: error: feature "threadapi" : "win32" "pthread" : "optional" "propagated" /home/travis/build/boostorg/boost-root/libs/thread/build/threadapi.jam:4: in load from module threadapi /home/travis/build/boostorg/boost-root/tools/build/src/kernel/modules.jam:295: in modules.import from module modules /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:1069: in import from module Jamfile</home/travis/build/boostorg/boost-root/libs/thread/build> libs/thread/build/Jamfile.v2:39: in modules.load from module Jamfile</home/travis/build/boostorg/boost-root/libs/thread/build> /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:325: in load-jamfile from module project /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:64: in load from module project /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:89: in load-used-projects from module project /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:75: in load from module project /home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:145: in project.find from module project /home/travis/build/boostorg/boost-root/tools/build/src/build-system.jam:535: in load from module build-system /home/travis/build/boostorg/boost-root/tools/build/src/kernel/modules.jam:295: in import from module modules /home/travis/build/boostorg/boost-root/tools/build/src/kernel/bootstrap.jam:139: in boost-build from module /home/travis/build/boostorg/boost-root/boost-build.jam:17: in module scope from module Any ideas? Thanks, John. --- This email has been checked for viruses by AVG. http://www.avg.com

4 5

[contract] auto_..._error regression tests fail on C++1z
by Lorenzo Caminiti 04 Oct '17

04 Oct '17

Hello all, I asked this question on compl.c++ list as well, given this is more of a general C++1z question than a Boost question. However, this is making some Boost.Contract regression tests fail on C++1z compilers so I wanted to ask it here as well hoping to get some info more quickly... Following code prevents copies outside its friend function f: // File: 05.cpp struct x { x() {} private: x(x const&) {} x& operator=(x const&) { return *this; } friend x f(); }; x f() { return x(); } int main() { auto xx = f(); return 0; } Correctly it does not compile up to C++1y because main cannot access the copy operations: $ clang++ -std=c++1y 05.cpp 05.cpp:14:15: error: calling a private constructor of class 'x' auto xx = f(); ^ 05.cpp:5:5: note: declared private here x(x const&) {} ^ 1 error generated. However, it compiles on C++1z?! $ clang++ -std=c++1z 05.cpp # Not compiler errors?! Why... what changed in C++1z that makes the above compile? How can I prevent copying x outside its friend function f in C++1z? Thanks, --Lorenzo

6 7

[outcome v2] How important is it that an Expected implementation is also provided?
by Niall Douglas 04 Oct '17

04 Oct '17

Dear list, I know it's been a fair few months since any news on Outcome v2. Ordinarily I'd be speaking at CppCon happening right now, but I instead chose Jens' Meeting C++ in November where I'll be speaking on Expected. Outcome v2 has undergone its period of maturation since it was completely rewritten to reflect peer review feedback last May. The new consensus design has fared very well after being put under heavy production use these last few months, and I expect it to return here for a second review before the end of this year. Outcome v2 will also be appearing in the WG21 October mailing, watch out for: * P0762R0: Concerns about `expected<T, E>` from the Boost.Outcome peer review * P0779R0: Proposing `operator try()` Outcome v2 currently implements the not published yet D0323R3 Expected proposal as part of its test suite as a refinement of what boost-dev thought Expected ought to be instead of what it is (ahem!). We run it against the Expected reference test suite, and it passes. So here's the question before any second peer review. Should Outcome v2 provide: 1. No Expected implementation at all, not even under a different name. Not its place. 2. The Expected implementation which the consensus on boost-dev felt the WG21 Expected ought to be (this is the current situation, and no we don't call it `expected<T, E>`). 3. A closely conforming, but not exactly conforming [1], implementation of WG21 Expected. Options 2 and 3 can be combined. But be aware that Peter rolled together an even more conforming Expected implementation using his variant2 library. I had been assuming people would be better advised to use his likely exactly conforming implementation, rather than Outcome v2's not exactly conforming implementation. Less surprise. Thoughts? Niall [1]: Known differences from P0323R3 `expected<T, E>` in this implementation: - `T` and `E` cannot be the same type. - No variant storage is implemented (note that technically speaking, D0323R3 does not require variant storage). -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

3 5

Boost CMake update
by paul 04 Oct '17

04 Oct '17

Hi all, So I have been working at converting more of boost tests to cmake utilizing the BCM library, here: https://github.com/boost-cmake/boost/tree/1.64 This is a build of Boost 1.64, with a majority of the tests integrated. There is still much more work needed to update the tests, as there are some that still fail. Also, some of the libraries were skipped due to missing headers in the 1.64 tag. You can check the library yourself by running cmake: cd build mkdir build cmake .. cmake --build . --target check This will build all the tests. You can check the tests for one target with: cmake --build . --target check-boost_core Which will run the tests for just `boost_core`. This was all generated using scripts in https://github.com/pfultz2/boost-cmake I plan to update this to a newer version of boost. If anyone has fixes or changes they can send a PR or issue on either repos, and I will try to incorporate them in. Thanks, Paul .

8 35

[beast] Supporting ICY 200 OK
by Vinnie Falco 04 Oct '17

04 Oct '17

Bjorn brought up the point that there are some niche cases where applications do not strictly follow the HTTP message syntax for responses. Specifically, for Shoutcast(?) / Icecast mp3 servers the status-line in the response looks something like this: ICY 200 OK\r\n I have thought about ways to support this directly in Beast but I have decided against it. "ICY 200" is not HTTP according to the RFC, and trying to accommodate this use case places needless technical debt in public interfaces. However, I came up with a very simple technique to make this work with Beast by writing just a tiny bit of extra code. The solution is to implement a stream wrapper which meets the requirements of SyncReadStream[1] and/or AsyncReadStream[2] and forwards the calls to read to the "next layer" object, which will be the actual socket or ssl::stream. The implementation of the icy_stream wrapper can check to see if the first 3 bytes received from the next layer match "ICY" and if so, return a buffer to the caller which replaces those characters with "HTTP/1.1" (or "HTTP/1.0"). With this wrapper, calls to beast::http::read or beast::http::async_read can parse the custom response as a regular HTTP message. The wrapper can embed state information to inform the caller if the "ICY" string was not received. The declaration for such a wrapper might look like this: template<class NextLayer> class icy_stream; Usage for the wrapper: asio::ip::tcp::socket sock{ios}; icy_stream<asio::ip::tcp::socket&> stream{sock}; beast::http::response<beast::http::empty_body> res; beast::multi_buffer buffer; beast::http::read(stream, buffer, res); This technique may of course be generalized to support any desired similar but non-standard HTTP requests or responses in a fashion that is completely transparent to Beast. Thanks [1] <http://www.boost.org/doc/libs/1_65_1/doc/html/boost_asio/reference/SyncRead…> [2] <http://www.boost.org/doc/libs/1_65_1/doc/html/boost_asio/reference/AsyncRea…>

2 4

Re: [boost] [beast] A Networking-TS version of Boost.Asio and Boost.Beast is here!
by Vinnie Falco 04 Oct '17

04 Oct '17

On Tue, Oct 3, 2017 at 9:40 AM, Vinnie Falco <vinnie.falco(a)gmail.com> wrote: > My preview of Boost.Asio version 1.66.0 is here: > > <https://github.com/vinniefalco/boost.asio/commits/net-ts> Upon re-reading the message I realize that it might be confusing, so to clarify - this is NOT an "official" version of Boost.Asio it is just an experimental branch of what Boost.Asio might look like soon, for anyone who wants to try out the latest stand-alone Asio features in the Boost.Asio context. Thanks

2 5

Boost.Buffers, a new library from the makers of Beast!
by Vinnie Falco 03 Oct '17

03 Oct '17

During the formal review of Beast, desires were expressed to use components like the HTTP parser and serializer independently from the rest of the library. The sticking point was the abstraction used to represent a range of non-owning buffers. In particular, Asio imposes certain concrete type requirements in its ConstBufferSequence and MutableBufferSequence concepts. It would seem there is significant interest in making some components of Beast modular, in their own libraries. The main feature of these components would be that they should not require Boost.Asio. Unfortunately, the way Asio's concepts are defined this is not possible. Two solutions present themselves: 1. Create a new buffer sequence concept which retains all the features of Asio's concepts but does not require the concrete types. While this is possible it would create a significant complication. Interfaces which use the new concept would require some kind of adapter at every call site that tries to use a traditional Asio style interface. 2. Create a new library which uses conditional compilation to either include just the Asio header files which fulfill the needs for interacting with buffer sequence concepts, or provide the declarations directly from a copy of the Asio sources. The solution used in Boost.Buffers (a new library I am considering proposing) is choice number two. Someone who wants to create a new library ("Foo") that does no network I/O but wants to interoperate with Asio buffer concepts merely need to do the following #include <boost/buffers.asio.hpp> and then, in their build script for the tests and examples, set: #define BOOST_NET_BUFFER_NO_ASIO 1 This works because Boost.Buffers contains copies of all the necessary header files to work with buffer sequences, and JUST those header files. All of Boost.Asio is not necessary: <https://github.com/vinniefalco/buffers/blob/30ef7031ec0909972a720c0cdd8d6c6…> Now if someone wants to use library Foo they will also be getting a dependency on Boost.Buffers. If that user doesn't need Asio, then they will also set the macro to 1 in their build script. However. if that user wants to use Asio in their program or library, they just set #define BOOST_NET_BUFFER_NO_ASIO 0 and now Boost.Buffers will simply include the relevant Asio header files. This library will allow the creation of new libraries which use Asio buffer concepts, but do not require all of Boost.Asio as a dependency, as well as all the things that Boost.Asio is dependent on, which is non-trivial as can be seen here: <https://github.com/boostorg/beast/blob/develop/.travis.yml#L140> I would like feedback on this library before I move forward with it, as you can imagine it has some controversial aspects to it. Boost.Buffers is here: <https://github.com/vinniefalco/buffers> Thanks

1 0

[beast] The Networking-TS version of Boost.Asio and Boost.Beast is here!
by Vinnie Falco 03 Oct '17

03 Oct '17

I have taken the tip of standalone Asio, from: <https://github.com/chriskohlhoff/asio/commits/asio-1-10-branch> and applied this "boostify.pl" script: <https://github.com/chriskohlhoff/asio/blob/asio-1-10-branch/asio/boostify.pl> plus a bit of manual fixing, to produce a new branch of Boost.Asio which is up-to-date with respect to the stand-alone Asio. This means you can have access to the Networking-TS changes that will be introduced in Boost.Asio (according to the author, this will be in Boost 1.66.0). My preview of Boost.Asio version 1.66.0 is here: <https://github.com/vinniefalco/boost.asio/commits/net-ts> Beast has been ported to this version of Asio, you can try it here: <https://github.com/vinniefalco/beast/commits/net-ts> When Boost.Asio is updated for 1.66.0 to bring it in-line with the standalone Asio (which supports Networking-TS), Beast will simultaneously be updated. Hopefully this will all be done in time for 1.66.0, so that users of the debut version of Beast will have the latest interfaces available for their use. Thanks!

1 0

Modularizing explicit-failures-markup.xml
by Daniel James 03 Oct '17

03 Oct '17

Hi, I'm looking into implementing a mechanism for updating explicit-failures-markup.xml without updating the super project. My basic idea is that modules can have a 'status/explicit-failures-markup.xml' file, and I'll write a script to update the super project file from modules. It will have the same format as the super project file, so can just copy and paste the relevant parts into your module. Does that sound okay? It might be better if the regression scripts handled this themselves, but I'm not sure if anyone would be available to implement that. Daniel

6 12

[asio] Verify SSL certificates using the OS-specific certificate store
by Vinnie Falco 01 Oct '17

01 Oct '17

My understanding of boost::asio::ssl::context is that it is just a small wrapper around OpenSSL. You can set default verify paths, but that assumes the certificates are in a particular directory which they almost never are. For example they might be in some OS-specific type of database which need system calls to access. If a program wants to use the native operating system facilities for verifying certificates, then I believe significant additional code is needed. Is this correct? I am interested in writing a simple function object which will validate a hostname and its accompanying certificate against the operating-system-dependent certificate authorities. Is there some code somewhere that does this? Any resources that I can be pointed to would be of immense value. Thanks

2 1

Re: [boost] [beast] Supporting ICY 200 OK
by Bjorn Reese 01 Oct '17

01 Oct '17

On 10/02/2017 12:06 AM, Vinnie Falco wrote: > However, I came up with a very simple technique to make this work with > Beast by writing just a tiny bit of extra code. The solution is to > implement a stream wrapper which meets the requirements of > SyncReadStream[1] and/or AsyncReadStream[2] and forwards the calls to > read to the "next layer" object, which will be the actual socket or > ssl::stream. Sounds like a good solution.

1 0

[review] The review period of Boost.DoubleEnded has been extended with one week. Now ends 7th of October.
by Thorsten Ottosen 28 Sep '17

28 Sep '17

Dear users and members of Boost, People have been requesting extra time for the review of Boost.DoubleEnded. We therefore continue one week extra, so the final date will be October the 7th. kind regards Thorsten Original review announcement ------------------------------------------ I'm proud to announce that the formal review of Benedek Thaler's Boost.DoubleEnded library starts today, September 21, and runs through September 30. This library is the result of Benedek's participation in Google Summer of Code 2015. The library may be downloaded from https://github.com/erenon/double_ended and the documentation may be found here: http://erenon.hu/double_ended/ Anyone is welcome to post a review and/or take part in subsequent discussions (see below for review guidelines). Introduction ------------ This is a container library that provides two containers: A. boost::devector B. boost::batch_deque Both containers provides efficient push_front and push_back operations, hence the name DoubleEnded. The boost::devector class can be seen as an extension of std::vector with efficient support for push_front (so boost::devector provides contiguous storage). In addition, it provides a customizable small buffer optimization like boost::small_vector(*). It furthermore allows for customization of the growth factor such that the user can decide if a reallocation should allocate 1.5 or 2 or whatever more memory. And finally it provides new functionality that does not exist in normal vector implementations -- this functionality allow the class to excel in performance in certain situations like serialization or transfer of data from sources that require a preallocated buffer. The boost::batch_deque is similar to std::deque, but with two important twists. Like std::deque, it provides reference stability when calling push_front/push_back. Reference stability is crucial for programs that uses intrusive containers e.g. using Boost.Intrusive (**). boost::batch_deque has the following main advantages: 1. It allows the user to specify the segment size 2. It allows for external iteration over the segments Taken together, they provide a very efficient and flexible basis for intrusive containers. Access to the segments also increases performance for tasks such as serialization. Finally, boost::batch_deque may be seen as an efficient alternative to std::vector if you want to replace a percent-wise memory overhead with a constant memory overhead and have no need for contiguous storage. Review guidelines ----------------- Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Boost.DoubleEnded as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Kind regards Thorsten, Review manager (*) boost::small_vector: https://tinyurl.com/ycslp4ot (**) http://www.boost.org/doc/libs/1_64_0/doc/html/intrusive.html -- Best regards, Thorsten Jørgen Ottosen, Ph.D. Director of Research +45 23308797 Dezide (www.dezide.com)

1 0

[admin] Turning on Issues tab on Github for Boost libraries
by Edward Diener 28 Sep '17

28 Sep '17

Can we not have some resolution from an administrator about turning on the Issues tab in Github for Boost libraries ? There are two 'admin' issues regarding this and, since it should be a quick job for an administrator to implement this, I would really prefer not to wait for a long time for this to get done. Just now I had a "bogus" PR for iostreams, which I rejected, and the explanation from the person who created the PR was that the PR was "created" because there was no Issue tab for the library and he was only trying to create an Issue to be looked at. There is absolutely no logical reason that I can think of why the Issue tab on Github cannot be turned on for Boost libraries, to benefit end-users.

3 3

Re: [boost] [ANN] Boost.UI - a new C++ GUI library
by Kolya Kosenko 28 Sep '17

28 Sep '17

On 09/28/2017 03:02 PM, Stefan Seefeld via Boost wrote: >> - uses native system-provided widgets > > what widgets do you consider "system-provided" ? What backends do you > bind to on the different platforms, and can those bindings be changed ? Native system-provided widgets means widgets from toolkits GTK+, Qt, Windows Controls, Cocoa etc. >> - compatible with other Boost libraries > > What does that mean ? Boost.Geometry and Boost.Polygon could be used with Boost.UI coordinates, Boost.Chrono - boost::ui::on_timeout() function, Boost.Date_Time library are used in date and time pickers etc. > I'd be interested in some high-level documentation explaining the basic > programming and execution model of the API. You can ask for implementation details here. Documentation explains only API. > For example, how are events > handled and how are they bound to particular actions ? Library subscribes to event handlers in native toolkit. When user press button, native event handler eventually calls Boost.UI event handler. > Are programs > inherently multi-threaded or single-threaded (e.g., does the main event > loop run in its own thread) ? There is main GUI thread and you should call GUI functions from other your own threads using boost::ui::call_async() function. Boost.UI library (like all other C++ GUI libraries) aren't thread safe because native toolkits are not thread safe. > Is your library mostly just a (thin) layer over existing > platform-specific GUI libraries, or does it reimplement a lot of the > logic itself ? Boost.UI is a rather thin layer with C++11/Boost support. > (And what is that cryptic "ui_main()" function ? :-) ) ui_main() function call required for GUI initialization, deinitialization, cleanup. It is required for underlying toolkits. Actually you can call some functions directly from main() function, but it is at your own risk. Regards, Kolya.

2 4

[1.65] [process] Library version outdated
by Andrey Semashev 28 Sep '17

28 Sep '17

Hi, It looks like something is broken in the release procedure, which resulted in all Boost 1.64.0, 1.65.0 and 1.65.1 to contain the same revision of Boost.Process 4075371cbe78dab8f43578c655747c831b554318 (you can see that by git tags). This revision is dated Wed Apr 5 11:32:27 2017, which is more like when 1.64.0 was being prepared. I know that 1.65 has long sailed, but can the release managers double check that this doesn't happen in 1.66? As a possible clue, on the local checkout I didn't have a head for the master branch for Boost.Process for some reason. I surely wasn't doing anythhing special with its repository, but maybe something happened on the remote side that caused this. I solved the problem locally by removing libs/process, .git/modules/process and running `git submodule update --init --recursive`.

3 3

[Pool] no maintainer, and should perhaps be deprecated?
by John Maddock 27 Sep '17

27 Sep '17

Moving this conversation to a new thread: >As an example of this: I recently proposed to add variadic move >construction for nodes to boost::pool (a trivial change). And even though >this has obvious advantages (and would get rid for C++11 capable compilers >of the use of M4 to generate the necessary code), this was received with: >file a PR, including tests (?) and change to documentation. Enough to put >me off, so I just changed it locally. Unfortunately the pool lib is not a good example - as previously stated it has no current maintainer - but as (probably) the last person to try and do some community maintenance on this library, the impression I came away with was that it needs rewriting. Actually more than that.... it probably needs redesigning if many more of the existing bug reports are to be fixed. I've actually said this on the list before, and suggested that Pool.2 might be a good candidate for as someone's first Boost library (since it's not too large), but so far no takers. There is possibly another issue: the performance of most std lib allocators has improved to the point that it's actually questionable whether using the pool lib has much real benefit (but this need quantifying so the cases where it does help are documented). Maybe that's what has put people off, or maybe it's just not sexy enough for anyone to take on, but I still hope that someone will.... Best, John. --- This email has been checked for viruses by AVG. http://www.avg.com

2 1

[multi_index] Taking advantage of C++17 auto template params to simplify key specification
by Joaquin M López Muñoz 27 Sep '17

27 Sep '17

Consider the following: struct element { int x; int f()const{return x;} }; int gf(const element& e){return e.x;} using container=multi_index_container< element, indexed_by< ordered_unique<member<element,int,&element::x>>, ordered_unique<const_mem_fun<element,int,&element::f>>, ordered_unique<global_fun<const element&,int,&gf>> > >; With the advent in C++17 of auto non-type template parameters, it is very easy to provide a boost::multi_index::key class template so that we can write: using container=multi_index_container< element, indexed_by< ordered_unique<key<&element::x>>, ordered_unique<key<&element::f>>, ordered_unique<key<&gf>> > >; (Example at http://coliru.stacked-crooked.com/a/5742c768cc093c03 ). Is there interest in adding this to Boost.MultiIndex? Comments on this or alternative syntaxes? Thank you, Joaquín M López Muñoz

5 9

Re: [boost] [review] The review of Boost.DoubleEnded starts today: September 21 - September 30
by Fletcher, John P 27 Sep '17

27 Sep '17

________________________________________ From: Thorsten Ottosen [tottosen(a)dezide.com] Sent: 26 September 2017 08:28 To: Fletcher, John P Subject: Re: [boost] [review] The review of Boost.DoubleEnded starts today: September 21 - September 30 >> Hi Fletcher, >> >> On another topic, I have not seen in the documentation any discussion of models for what is going on. I am aware of Chris Okasaki's book "Purely Function Data Structures" (1998) and a lot of subsequent literature. Does this work relate at all to previous work? >I'm not familiar with that book. You should think of standard C++ >containers like std::vector and std::deque which models a sequence concept: I should have given a reference. Here is one. http://okasaki.blogspot.co.uk/2008/02/ten-years-of-purely-functional-data.h… This is the authors comments on 10 years from publication. If you put the title into google you will get lots of information. My point is that there is a strong theoretical basis in this area and one of the issues for me is how far this has been taken into account in this new work. I was not until recently familiar with the work. It has helped me a lot understand the underlying problems in this area and I want to know whether the author of the library has looked at it. There is nothing in the documentation that I have seen about the wider issues. John Fletcher

2 1

Please fix executable permissions on header files
by Jonathan Wakely 25 Sep '17

25 Sep '17

The following files have executable permission bits set, which causes warnings for me when packaging Boost for Fedora (and is just wrong, because they're not executables): $ find boost_1_65_1/boost -name '*.hpp' -perm /111 boost_1_65_1/boost/numeric/conversion/detail/old_numeric_cast.hpp boost_1_65_1/boost/python/converter/arg_to_python.hpp boost_1_65_1/boost/python/converter/context_result_converter.hpp boost_1_65_1/boost/python/converter/pytype_function.hpp boost_1_65_1/boost/python/converter/return_from_python.hpp boost_1_65_1/boost/python/detail/convertible.hpp boost_1_65_1/boost/python/detail/copy_ctor_mutates_rhs.hpp boost_1_65_1/boost/python/detail/def_helper_fwd.hpp boost_1_65_1/boost/python/detail/is_shared_ptr.hpp boost_1_65_1/boost/python/detail/is_wrapper.hpp boost_1_65_1/boost/python/detail/nullary_function_adaptor.hpp boost_1_65_1/boost/python/detail/prefix.hpp boost_1_65_1/boost/python/detail/python_type.hpp boost_1_65_1/boost/python/detail/sfinae.hpp boost_1_65_1/boost/python/detail/unwind_type.hpp boost_1_65_1/boost/python/detail/unwrap_type_id.hpp boost_1_65_1/boost/python/detail/unwrap_wrapper.hpp boost_1_65_1/boost/python/detail/value_arg.hpp boost_1_65_1/boost/python/object/function_doc_signature.hpp boost_1_65_1/boost/python/object/inheritance_query.hpp boost_1_65_1/boost/python/object/stl_iterator_core.hpp boost_1_65_1/boost/python/arg_from_python.hpp boost_1_65_1/boost/python/base_type_traits.hpp boost_1_65_1/boost/python/borrowed.hpp boost_1_65_1/boost/python/cast.hpp boost_1_65_1/boost/python/def_visitor.hpp boost_1_65_1/boost/python/docstring_options.hpp boost_1_65_1/boost/python/handle_fwd.hpp boost_1_65_1/boost/python/object.hpp boost_1_65_1/boost/python/object_protocol_core.hpp boost_1_65_1/boost/python/raw_function.hpp boost_1_65_1/boost/python/refcount.hpp boost_1_65_1/boost/python/self.hpp boost_1_65_1/boost/python/stl_iterator.hpp boost_1_65_1/boost/python/wrapper.hpp boost_1_65_1/boost/interprocess/detail/managed_memory_impl.hpp boost_1_65_1/boost/interprocess/detail/managed_multi_shared_memory.hpp boost_1_65_1/boost/interprocess/detail/managed_open_or_create_impl.hpp boost_1_65_1/boost/interprocess/detail/shared_dir_helpers.hpp boost_1_65_1/boost/bimap/container_adaptor/unordered_associative_container_adaptor.hpp boost_1_65_1/boost/parameter/aux_/preprocessor/flatten.hpp boost_1_65_1/boost/parameter/aux_/preprocessor/for_each.hpp boost_1_65_1/boost/parameter/aux_/python/invoker_iterate.hpp boost_1_65_1/boost/parameter/aux_/overloads.hpp boost_1_65_1/boost/parameter/aux_/parameter_requirements.hpp boost_1_65_1/boost/parameter/aux_/result_of0.hpp boost_1_65_1/boost/parameter/aux_/tag.hpp boost_1_65_1/boost/parameter/aux_/template_keyword.hpp boost_1_65_1/boost/parameter/aux_/void.hpp boost_1_65_1/boost/parameter/aux_/yesno.hpp boost_1_65_1/boost/parameter/match.hpp boost_1_65_1/boost/parameter/parameters.hpp boost_1_65_1/boost/parameter/python.hpp boost_1_65_1/boost/parameter.hpp boost_1_65_1/boost/ptr_container/detail/default_deleter.hpp boost_1_65_1/boost/ptr_container/detail/is_convertible.hpp boost_1_65_1/boost/ptr_container/detail/move.hpp boost_1_65_1/boost/ptr_container/detail/scoped_deleter.hpp boost_1_65_1/boost/ptr_container/detail/throw_exception.hpp boost_1_65_1/boost/ptr_container/detail/void_ptr_iterator.hpp boost_1_65_1/boost/ptr_container/exception.hpp boost_1_65_1/boost/ptr_container/nullable.hpp boost_1_65_1/boost/thread/concurrent_queues/queue_base.hpp boost_1_65_1/boost/thread/experimental/parallel/v2/task_region.hpp boost_1_65_1/boost/thread/v2/shared_mutex.hpp boost_1_65_1/boost/iostreams/detail/adapter/device_adapter.hpp boost_1_65_1/boost/iostreams/detail/adapter/filter_adapter.hpp boost_1_65_1/boost/iostreams/detail/adapter/non_blocking_adapter.hpp boost_1_65_1/boost/iostreams/detail/broken_overload_resolution/forward.hpp boost_1_65_1/boost/iostreams/detail/config/enable_warnings.hpp boost_1_65_1/boost/iostreams/detail/config/limits.hpp boost_1_65_1/boost/iostreams/detail/config/windows_posix.hpp boost_1_65_1/boost/iostreams/detail/absolute_path.hpp boost_1_65_1/boost/iostreams/detail/bool_trait_def.hpp boost_1_65_1/boost/iostreams/detail/counted_array.hpp boost_1_65_1/boost/iostreams/detail/template_params.hpp boost_1_65_1/boost/iostreams/restrict.hpp boost_1_65_1/boost/msm/mpl_graph/mpl_graph.hpp boost_1_65_1/boost/typeof/dmc/typeof_impl.hpp boost_1_65_1/boost/typeof/std/bitset.hpp boost_1_65_1/boost/typeof/std/complex.hpp boost_1_65_1/boost/typeof/std/deque.hpp boost_1_65_1/boost/typeof/std/fstream.hpp boost_1_65_1/boost/typeof/std/functional.hpp boost_1_65_1/boost/typeof/std/iostream.hpp boost_1_65_1/boost/typeof/std/istream.hpp boost_1_65_1/boost/typeof/std/iterator.hpp boost_1_65_1/boost/typeof/std/list.hpp boost_1_65_1/boost/typeof/std/locale.hpp boost_1_65_1/boost/typeof/std/map.hpp boost_1_65_1/boost/typeof/std/memory.hpp boost_1_65_1/boost/typeof/std/ostream.hpp boost_1_65_1/boost/typeof/std/queue.hpp boost_1_65_1/boost/typeof/std/set.hpp boost_1_65_1/boost/typeof/std/sstream.hpp boost_1_65_1/boost/typeof/std/stack.hpp boost_1_65_1/boost/typeof/std/streambuf.hpp boost_1_65_1/boost/typeof/std/string.hpp boost_1_65_1/boost/typeof/std/utility.hpp boost_1_65_1/boost/typeof/std/valarray.hpp boost_1_65_1/boost/typeof/std/vector.hpp boost_1_65_1/boost/typeof/encode_decode.hpp boost_1_65_1/boost/typeof/encode_decode_params.hpp boost_1_65_1/boost/typeof/incr_registration_group.hpp boost_1_65_1/boost/typeof/int_encoding.hpp boost_1_65_1/boost/typeof/integral_template_param.hpp boost_1_65_1/boost/typeof/modifiers.hpp boost_1_65_1/boost/typeof/pointers_data_members.hpp boost_1_65_1/boost/typeof/register_mem_functions.hpp boost_1_65_1/boost/typeof/template_encoding.hpp boost_1_65_1/boost/typeof/template_template_param.hpp boost_1_65_1/boost/typeof/type_encoding.hpp boost_1_65_1/boost/typeof/type_template_param.hpp boost_1_65_1/boost/typeof/typeof_impl.hpp boost_1_65_1/boost/typeof/vector.hpp boost_1_65_1/boost/typeof/vector100.hpp boost_1_65_1/boost/typeof/vector150.hpp boost_1_65_1/boost/typeof/vector200.hpp boost_1_65_1/boost/typeof/vector50.hpp

5 7

request git repository for boost.contract
by Lorenzo Caminiti 25 Sep '17

25 Sep '17

Hello all, I need some help... who should I ask to create a git repository "contract" for boost.contract? How do I link that to the main boost repository in git? Please send me link if this info is already documented somewhere. Thank you. --Lorenzo

2 2

[review][Fit] Fit Review Results
by Matt Calabrese 25 Sep '17

25 Sep '17

Hello everyone, It is my privilege to announce that the Boost library count will once again be incremented as Paul Fultz II's library Fit has been accepted into Boost without conditions. Further details about this decision follow, but before that I'd like to thank Paul for all of the hard work he has put into Fit. Thanks also to everyone who participated in the review, with additional thanks to Vicente who was the review manager for the previous Fit review and who also provided a very detailed review and discussion during this review period. //////////////////////////////////////////////////////////////////////////////// Overview //////////////////////////////////////////////////////////////////////////////// Complete Reviews Considered: Zach Laine: Accept Vicente J. Botet Escriba: Accept John P. Fletcher: Accept Robert Ramey: Accept Jason Rice: Accept Barrett Adair: Accept Lee Clagett: Accept Glen Fernandes: Accept Louis Dionne: Accept Partial Reviews/Discussions Considered: Edward Diener Andrea Bocci Further Discussions (Previous Review): Steven Watanabe Peter Dimov Vladimir Batov Gavin Lambert Rob Stewart Bjorn Reese Manu Sanchez Artyom Beilis //////////////////////////////////////////////////////////////////////////////// Summary //////////////////////////////////////////////////////////////////////////////// Though not all responders reviewed every single aspect of the library, the reviews together adequately covered everything that is necessary for a decision to be made. This decision is made with additional confidence coming from usage of the library by some reviewers going back since during or before the initial review in early 2016. //////////////////////////////////////////////////////////////////////////////// Improvements Since Previous Review //////////////////////////////////////////////////////////////////////////////// This time around we received several more complete reviews than in the previous review period making it easier to be confident in a decision. A couple of notable changes since the 2016 review include: * Improved documentation * Default semantics for "capture" no longer try to determine whether to capture by reference or by value based on the argument being an lvalue or an rvalue (users can still get this via basic_capture) * Improved ADL awareness (internal calls are qualified) Throughout all of the discussions in this second review period, there were no explicit rejections of the library as a whole, though there were several recommendations from participants. A selection of those are listed here, though no changes are strictly required for acceptance: //////////////////////////////////////////////////////////////////////////////// Current Concerns //////////////////////////////////////////////////////////////////////////////// ////////// Design concerns: * Inheritance from user-callables has some potential pitfalls * Generated "infix" operators are "gimmicky" and don't add much value/may cause confusion * Placeholders should live in their own namespace ////////// Documentation concerns (not a complete list): * More examples requested * It is not always clear what files need to be #included for certain facilities in early examples * Better rationale for ConstFunctionObjects * Raw code is not linked from the examples ////////// Suggested name changes from reviewers: * Suggested rename of "partial()" to "partial_apply()" or "curry()" * Suggested rename of "conditional()" to "invoke_first()" or "call_first_of()" * Suggested rename of "apply" to "invoke" * Refer to "Callables" instead as "Invocables" (due to C++17 direction) * Library name "Fit" is not indicative of what it provides //////////////////////////////////////////////////////////////////////////////// Regarding the Author //////////////////////////////////////////////////////////////////////////////// Paul has been active in the Boost community for several years now. He is aware of his responsibilities going forward and I am confident that he will be a reliable maintainer for Fit for the foreseeable future (or whatever the library may be called). //////////////////////////////////////////////////////////////////////////////// Comments on the Name Boost.Fit //////////////////////////////////////////////////////////////////////////////// Note that what I say here is my personal opinion as a member of the community and does not necessarily reflect the opinions of others in the community nor of those in the steering committee. A few reviewers voiced that they would like to see a change of the library name "Fit". While multiple people did suggest this, my opinion is that this should be up to the author to choose whether or not he will change the name before it is added to boost and so I do not think it would be appropriate for us to strictly require or encourage such a change. If the author found the arguments against the name compelling, then he is welcome to change the name, but he should not feel obligated to do so. As a quick note on that, we have several high quality and highly regarded libraries in Boost with names that may not directly tell users what the library is for. Based on their popularity, I do not believe that it has significantly negatively affected their usage or ability to be found. A library name also may be important to an author as a creative outlet and I think it would be... poor form us to force such a change in this particular case and in other cases unless there are very strong reasons (i.e. the name is overly or intentionally misleading or there are legal concerns). I am not convinced that the current name is misleading enough to strictly require a change. As for existing precedent, some examples of libraries already in Boost with names that do not directly tell the user what the library is for include some of Boost's most highly regarded libraries such as Boost.Spirit (including Qi and Karma), Boost.Phoenix, Boost.Wave, Boost.Hana, and the recently accepted Boost.Beast. //////////////////////////////////////////////////////////////////////////////// Thanks again to everyone who participated in this review and in the previous review, and once again, congratulations to Paul on his library's acceptance into Boost. -- -Matt Calabrese

4 3

[utility] [config] value_init tests on msvc-14.0, 14.1
by Peter Dimov 24 Sep '17

24 Sep '17

Currently, value_init_workaround_test.cpp fails on both msvc-14.0 and 14.1, because in: #ifdef BOOST_DETAIL_VALUE_INIT_WORKAROUND_SUGGESTED // One or more failures are expected. return num_failures > 0 ? EXIT_SUCCESS : EXIT_FAILURE; #else // No failures are expected. return num_failures == 0 ? EXIT_SUCCESS : EXIT_FAILURE; #endif failures are supposedly expected (BOOST_DETAIL_VALUE_INIT_WORKAROUND_SUGGESTED is defined), but there are none. BOOST_DETAIL_VALUE_INIT_WORKAROUND_SUGGESTED is controlled by BOOST_NO_COMPLETE_VALUE_INITIALIZATION, which is defined on 14.0/14.1. The Config macro is defined because - presumably - msvc 14.0/14.1 fail the Config test for value initialization, boost_no_com_value_init.ipp. But this test is much more comprehensive than the value_init one. So to fix the value_init_workaround_test.cpp failure, we need to at minimum move one failing test case from the Config test to the value_init one.

2 3

Modular Packages on Conan.io
by Rene Rivera 24 Sep '17

24 Sep '17

One of the most requested feature from Boost users is having a "modular" distribution. I'm happy to announce that there are now modular packages available when using the Conan package manager from the Bincrafters team < http://bit.ly/2wM5AdT>[1]. Using the packages requires no prior setup other than the Conan tool. Immediately available are all 130 libraries from the 1.64.0 release. And in a few days we will follow up with the same for the 1.65.1 release. For help using the packages you can bug the Bincrafters team <http://bit.ly/2xWEGEX>[3] in the #conan cpplang.slack.com channel < http://bit.ly/2hnMB3o>[4]. Conan is a C/C++ (and more) package manager that supports an open ended set of build system and tool integrations including: VisualStudio, Xcode, CLion, Ninja, QMake, Premake, and yes even CMake <http://bit.ly/2xzhpbg>[2]. [1] <https://bincrafters.github.io/2017/09/22/boost-modular-packages-conan/> [2] <http://docs.conan.io/en/latest/integrations.html> [3] <https://bintray.com/bincrafters/public-conan> [4] <https://cpplang.slack.com/messages/C41CWV9HA> -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

4 5

Including open source, non-copyright, no warranty in a boost library
by James E. King, III 24 Sep '17

24 Sep '17

Hello, I'm working on refactoring boost::uuids::name_generator to have a configurable hash algorithm through a template concept. RFC 4122 allows for two hashing algorithms, MD5 and SHA1. The current implementation only does SHA1, however I want to add MD5 for completeness (and I want to prepare for the eventual successor to SHA1 in the next RFC for UUID). I found an open source MD5 implementation of RFC 1321 at the following location and I was wondering if there are rules against bringing it into boost as a detail implementation? http://openwall.info/wiki/people/solar/software/public-domain-source-code/m… Thanks, Jim

4 3

BCM - Boost CMake Modules request for endorsement
by paul 22 Sep '17

22 Sep '17

Hi, So the Daniel Pfeifer has agreed to be the review manager for the Boost Cmake Modules. I would like ask for an endorsement so we can schedule a formal review for BCM. Thanks, Paul .

5 7

Travis/Appveyor improvements for the superproject
by Peter Dimov 22 Sep '17

22 Sep '17

Travis and Appveyor tests for the Boost superproject have been improved to automatically run the tests for the library mentioned in the commit message. For example, if the message is "Update iterator from develop", the corresponding CI job runs the tests of the Iterator library (among other things). This is a bit redundant if the library itself has Travis/Appveyor set up, but keeping an eye on https://ci.appveyor.com/project/boostorg/boost/history and https://travis-ci.org/boostorg/boost/builds can't hurt. For example, Appveyor says that Iterator fails a test on msvc-12.0 (Visual Studio 2013): https://ci.appveyor.com/project/boostorg/boost/build/1.0.3744-develop and Utility fails a test on msvc-14.0/msvc-14.1: https://ci.appveyor.com/project/boostorg/boost/build/1.0.3765-develop

9 16

[review][Fit] Review of Fit starts today : September 8 - September 17
by Matt Calabrese 22 Sep '17

22 Sep '17

A formal review of the Fit library developed by Paul Fultz II starts today, September 8, and runs through September 17. A branch has been made for the review. You can find Fit for review at these links: Source: https://github.com/pfultz2/Fit/tree/boost Docs: http://pfultz2.github.io/Fit/doc/html/doc/ Anyone who is able to provide an assessment of the design, implementation, and/or docs can participate in this review. Usage experience is not absolutely necessary to give feedback, but is highly recommended if you are writing a review. Discussions about aspects of the library are welcome even if a complete review is not presented, though participants are asked to please state whether they would like to accept or reject the library before the deadline of September 17, paying close attention to the questions raised at the end of this email. The success of Boost is partially a result of the quality review process which is conducted by the community. You are part of the Boost community. We will be grateful to receive a review based on whatever level of effort or time you can devote. This is the second time that Fit will go through the review process, with the previous time being in March of 2016. The result of the initial review can be found here: https://lists.boost.org/Archives/boost/2016/04/228770.php In this second review, those who choose to participate should be as rigorous as they'd be in any other review, but are also encouraged to voice whether or not the concerns from March of 2016 were addressed. The following is a brief description of the library from its author: ==================== Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects, which can solve many problems with much simpler constructs than whats traditionally been done with metaprogramming. Fit is: Modern: Fit takes advantages of modern C++11/C++14 features. It support both constexpr initialization and constexpr evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: Function Adaptors and Decorators: These enhance functions with additional capability. Functions: These return functions that achieve a specific purpose. Utilities: These are general utilities that are useful when defining or using functions. Requirements This requires a C++11 compiler. There are no third-party dependencies. This has been tested on clang 3.5-3.8, gcc 4.6-6.2, and Visual Studio 2015. Gcc 5.1 is not supported at all, however, gcc 5.4 is supported. Contexpr support: Both MSVC and gcc 4.6 have limited constexpr support due to many bugs in the implementation of constexpr. However, constexpr initialization of functions is supported when using the FIT_STATIC_FUNCTION and FIT_STATIC_LAMBDA_FUNCTION constructs. Noexcept support: On older compilers such as gcc 4.6 and gcc 4.7, noexcept is not used due to many bugs in the implementation. Also, most compilers don’t support deducing noexcept with member function pointers. Only newer versions of gcc(4.9 and later) support this. ==================== Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Fit as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? - Were the concerns from the March 2016 review of Fit addressed? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Thank you for participating! -- -Matt Calabrese

13 39

Crypto/hashes library?
by James E. King, III 21 Sep '17

21 Sep '17

Hello, The boost uuid module contains an implementation of the sha1 hash algorithm for purposes of generating a uuid from arbitrary input. I've opened an issue on github to make the hash algorithm configurable: https://github.com/boostorg/uuid/issues/26 I was hoping to find a concept and implementation of a few hashes somewhere in boost that could be used instead, however I haven't found any. Back in 2010 someone posted a link to a "boost::hashes" repository but I was unable to see what the outcome of the discussion was other than that it was not included. A collection of hashing algorithms that are well tested would be quite useful in a number of ways; and I like the hash size template style used in the repo from 2010: https://svn.boost.org/svn/boost/sandbox/hash/ Indeed there's mention of a discussion about the proper placement of sha1 inside boost::uuid in there: https://svn.boost.org/svn/boost/sandbox/hash/libs/hash/doc/html/rationale.h… So I was curious where that effort ended up, and if there was a resolution on whether an independent library for hashing was ultimately something that folks wanted to pursue or avoid. Thanks, Jim

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[move] [container] workaround for incorrect [-Wignored-attributes]
by Groke, Paul 21 Sep '17

21 Sep '17

Hi, we've stumbled over a supposed bug in GCC 6 that generates incorrect [-Wignored-attributes] warnings. Using anything in Boost that relies on boost::move_detail::aligned_storage (like boost::container::small_vector), with a small enough type, will trigger this warning when compiling for certain architectures with at least GCC 6.2~6.4. Affected architectures are e.g. SPARC and ARM - not affected are x86 and ARM64. GCC bug ticket: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82270 It would be possible to work around this issue by changing the implementation of boost::move_detail::aligned_storage_impl so that the aligned type no longer carries the attribute(aligned) itself, but just contains a member which carries that attribute. If I understand this correctly this should have the same effect (barring compiler bugs). Question: Would a pull request for such a change be welcome? Regards, Paul Groke

2 1

Mini review of the Fit library
by Glen Fernandes 21 Sep '17

21 Sep '17

What follows is my mini review of the Fit library. I had no time to write a full review, but feel that most of my points have been covered by others in both the first and this second review. A. Should the library be accepted into Boost? Yes; I vote to accept Fit - with no conditions for acceptance. B. What is your evaluation of the design? I found it: 1. Practical: For facilities like BOOST_FIT_LIFT. 2. Innovative: For facilities like infix(). And overall useful. C. What is your evaluation of the implementation? Good. Appears to be correct C++ code, and is definitely written in a very maintainable way. Ordinarily I'm in favor of not seeing macros used for what is accomplished by FIT_INHERIT_DEFAULT, FIT_INHERIT_CONSTRUCTOR, and similar, but this is a minor thing, and it does serve to make the code smaller and easier to review. I also like that the lowest version of C++ standard support required is C++11 (and not higher), as I am still aware of a large enough pre-C++14 user base that do have access to and use Boost libraries. D. What is your evaluation of the documentation? Excellent. Better than what I generally write. Useful enough for me, and in my opinion, sufficient for understanding the library and learning how to use it - for any user that takes the time to read through it all. E. What is your evaluation of the potential usefulness of the library? I believe it to be useful, and I know of at one developer that I have suggested Fit to, that has started using it - and another that would like to start using it if it is included in a Boost release (for which their organization has blanket approval to use). F. Did you try to use the library? With which compiler(s)? Did you have any problems? Not recently, but Yes. With g++ 6.3. I encountered no problems. G. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I had spent at least 3+ hours looking into Fit with the intention of reviewing it for my own use, and learning how one part of it was implemented. I did not have a chance to spend as much time as I would normally have to write a full review of the library. H. Are you knowledgeable about the problem domain? Familiar with enough functional programming design and generic programming to appreciate the library. Other notes: No concern about the name. We have Beast, Hana, Spirit; Fit is a fine enough name, and boost::fit:: is a convenient enough prefix. Glen

2 1

docs to release a new lib
by Lorenzo Caminiti 21 Sep '17

21 Sep '17

Hello all, Where are the latest docs to add a new lib to Boost (including regression tests, PDF docs, etc.)? Poking around a bit I found the following links... https://svn.boost.org/trac10/wiki/StartModMaint https://svn.boost.org/trac10/wiki/DeveloperChecklist I'm asking because I'm considering adding Boost.Contract to the Boost 1.66.0 release. Thanks a lot! --Lorenzo

1 0

[review] Final Notice! Fit Review Ends Today!
by Matt Calabrese 20 Sep '17

20 Sep '17

Hi everyone, The formal review of the Fit library is ending today, September 20th. For anyone who was waiting until the last minute to submit a review, this would be it. Anything that you can provide is helpful in making a decision, even if you do not write a complete review of the entire library. You can find Fit for review at these links: Source: https://github.com/pfultz2/Fit/tree/boost Docs: http://pfultz2.github.io/Fit/doc/html/doc/ Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Fit as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? - Were the concerns from the March 2016 review of Fit addressed? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Thank you for participating! -- -Matt Calabrese

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Re: [boost] [review][Fit] Review of Fit starts today
by Jason Rice 19 Sep '17

19 Sep '17

Please consider this review for the proposed Boost.Fit library. I recommend the review manager ACCEPT this library for inclusion in Boost without condition. # What is your evaluation of the design? - Making high order functions easier and more concise is a good idea. - I like the point-free programming features. - Some of the names, conventions, and errors would take any kind of user some getting used to. - A version of `alias_value` that works in a generic context where the type might not be an alias would be more useful I think. # What is your evaluation of the implementation? - The code is consistent across implementations and the files are pretty flat - Each function can be included independently which is nice. - It appears that there is some effort towards making errors easier to read. For instance, I called `fit::partial` with too many arguments and the error was "error: no member named 'fit_function_param_limit'" - There is some readability issues due to compiler compatibility support and specific compiler error workarounds. - I noticed `fit::decay` is not used in the tests at all. It gets included in `example.h` but is never used. # What is your evaluation of the documentation? - I like that the documentation is easy to read in the comments of each file. - Some of the wording in the descriptions weren't very helpful for me personally, but the "Semantics" section seemed to always get the point of the function across. # What is your evaluation of the potential usefulness of the library? - It seems parts of the library might not be that useful if you have constexpr lambdas, but I believe there are still features that enable more concise coding even against latest C++17 features. - I will probably use this library now that I am familiar with it. # Did you try to use the library? With which compiler(s)? Did you have any problems? - I made a couple of my own examples. - I used a fairly recent fork of clang trunk with c++1z. - BOOST_FIT_RETURNS *crashed the compiler* when I was trying to construct an std::array with some pack expansion. It looked like it crashed the parser. # How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - I spent a couple of hours looking at the docs in the source and making my own test programs to see how it could be used. # Are you knowledgeable about the problem domain? - I've used Boost.Hana a lot with its "functional" features. - I've done a lot of point free programming with RamdaJS in Javascript # Were the concerns from the March 2016 review of Fit addressed? N/A For what it's worth here is a link to some of my attempts to sample the library: https://gist.github.com/ricejasonf/9bfd233b3bc282eae9ecb8bc3198d948 Thank You, Jason Rice

2 1

[Container] small flat set ?
by Phil Endecott 18 Sep '17

18 Sep '17

Dear all, boost::container::small_vector and boost::container::static_vector are great. boost::container::flat_set is great too. But today I need a small_flat_set! And I don't think it's possible to compose flat_set and small_vector. (flat_set can use a custom allocator, but it can't take a custom implementation type in the way that, for example, std::priority_queue can.) Having said that, maybe composing flat_set and small_vector (or static_vector) isn't the optimum solution for the case where I will store something like 0...4 ints; I suspect that linear search in an unordered sequence will be quicker. But that gets complicated if you need iterators with the normal behaviour. Any thoughts? Regards, Phil.

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Last Day for Boost Community Dinner Sign up
by Jon Kalb 18 Sep '17

18 Sep '17

Boost Developers, Today is the last day to register for the Boost Community Dinner at CppCon. http://sched.co/Bhcr You do not need to be registered to attend CppCon to register for the Boost Community Dinner: https://cppcon.org/registration/ If you are going to be in the Seattle area a week from Tuesday, join us for a rare face-to-face get together of the Boost Community. See you there. Jon

1 0

[docs] Documentation on Github?
by John Maddock 18 Sep '17

18 Sep '17

I notice that a few libraries are serving their documentation pages on github, for example http://boostorg.github.io/quickbook/doc/html/index.html How is this being done? Thanks! John. --- This email has been checked for viruses by AVG. http://www.avg.com

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[review] Reminder that Fit Review Is Ending Soon. Please review!
by Matt Calabrese 16 Sep '17

16 Sep '17

Hi everyone, The formal review of the Fit library was scheduled to end tomorrow, September 17. At this point we do not have very many reviews and so we are extending the review period until the 20th. Anyone who can is encouraged to participate. Anything that you can provide is helpful in making a decision, even if you do not write a complete review of the entire library. You can find Fit for review at these links: Source: https://github.com/pfultz2/Fit/tree/boost Docs: http://pfultz2.github.io/Fit/doc/html/doc/ Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Fit as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? - Were the concerns from the March 2016 review of Fit addressed? More information about the Boost Formal Review Process can be found here: http://www.boost.org/community/reviews.html Thank you for participating! - Matt Calabrese

1 0

[winapi] Enable Travis and AppVeyor
by Andrey Semashev 16 Sep '17

16 Sep '17

Hi, I'm trying to enable Travis and AppVeyor builds for Boost.WinAPI, and Travis says that I need admin rights on the project to do it: https://travis-ci.org/boostorg/winapi I don't know if AppVeyor also needs admin rights, maybe someone with more experience could clarify. Could I have the admin rights for Boost.WinAPI? Or maybe boostorg admins could do the necessary steps to enable the project in Travis and AppVeyor? Thanks.

2 7

Searching for Review Manager for reflection library without macro
by Antony Polukhin 15 Sep '17

15 Sep '17

Hello, PFR is a C++14 library that provides tuple-like methods for aggregate initializables. Library has a set of predefined operators and useful functions for everyday use. Works with user-defined types without any macro or boilerplate code. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Anyone wishing to become a Review Manager for the library? Boost libraries that may benefit from PFR: * Convert - for out-of-the-box conversions of user types * Hana - for using user types instead of tuples * Intrusive - for reusing unused bits in user provided types * Serialization - for out-of-the-box serialization of user types * Spirit - for putting rule results into user provided types without Phoenix or Fusion macro * Test - for outputting content of user provided types * TypeTraits - for traits like has_unique_object_representations in C++14 -- Best regards, Antony Polukhin

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boost::random, header-only, boost::uuids::detail::seed_rng, and UWP development
by James E. King, III 14 Sep '17

14 Sep '17

Hi folks, It looks like the only reason boostorg/random is not a header-only library is due to random_device (it is the only src/ file: https://github.com/boostorg/random/tree/develop/src) The older WinCrypt calls are not available in some Windows platforms going forward, so this is going to become a problem pretty quickly for the community. In the boostorg/uuid library there is a seed_rng class which is doing similar things (however providing more entropy) and the library is header-only. In addition there are two filed defects - one in Trac and one in github issues, about uuid being incompatible with UWP applications (that's Windows universal apps). In uuid, I started adding support for BCrypt which is a Windows API supported on later versions of Windows, and once I changed my build flags to target Windows 10 and WINAPI_FAMILY_APP, I started getting build failures in random_device. On further inspection it looks like the random library doesn't have support for BCrypt yet, and even worse as a source library one would need to build two variants - one for WinCrypt and one for BCrypt to support older and newer windows platforms. There are also some implications on MinGW, as the older original MinGW has support for WinCrypt and MinGW-64 supports both. I'm going to propose that the implementation from boost::uuids::detail::seed_rng be moved into boost::random as the new random_device implementation. At the same time, boost::random will become header-only, and thus support setting _WIN32_WINNT at build time of consuming applications properly, and therefore support new Windows platforms properly. At the same time I would like to change seed_rng such that it no longer silently ignores some return values, and does not disable any compiler warnings (deprecations, currently). Thoughts? Thanks, - Jim

6 15

C++17 detection
by Robert Ramey 14 Sep '17

14 Sep '17

How do I get ready for C++17? I have a piece of code which requires C++14. I want to use something from C++17 but I also want my code to work now. So I have #if C++14 being used namespace std { // implement C++ function } // std I've looked in the documentation for Boost.Config and can't find any hints there. What is the best way to do this? Robert Ramey

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[review queue] we seem to have double allocated early September for review --- what to do?
by Thorsten Ottosen 12 Sep '17

12 Sep '17

Hi All, I was about to announce the start of the Boost.Double_ended review, running from today to 17th of September. This is what we agreed upon with John (Phillips). Now, when I look at http://www.boost.org/community/review_schedule.html it seems that there is also a review of the Fit library scheduled, greatly overlapping with Boost.Double_ended. Do we run two reviews simultaneously, or what? kind regards Thorsten

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Re: [boost] Review Request: impl_ptr (pimpl)
by Vladimir Batov 11 Sep '17

11 Sep '17

On 2017-08-19 23:55, Mario Lang wrote: > Vladimir Batov via Boost <boost(a)lists.boost.org> writes: > ... > I got interested enough by this posting so that I ended up doing my own > mini-review just right now :-). And I just wanted to let you know (and > encourage you) that I like this one alot. Keeping the public interface > free of boilerplate is quite nice! Mario, Thank you for your input. Much appreciated... although somewhat early. :-) It was pointed out to me that Boost review procedures changed and a proposal has to be endorsed before it can move to the review stage. So far I do not see it happening... maybe because the list is quiet (overall), maybe because iml_ptr is not good enough to attract that support/endorsement, maybe giving "endorsement" puts too much pressure and people shy away from it. We'll see. > I think for a full boost review, you will probably need to work on: > * The documentation > While I gave it a read, I ended up skipping to your test case because > I wanted to see working example code. > While the current docs have quite some examples, they spend a lot > more > screen space with showing what impl_ptr tries to replace, without > showing a good motivating positive example of how it actually looks > when employed. It also feels like it is spending some time with > marketing speak, while not really showing what it is trying to sell: Yes, I hear you... and I (at least partially) agree with you. First, no code or documentation will ever be to everyone's liking... unless everyone writes their own. Secondly, the documentation reflects many discussions we've had on this list about pimpl. For ex., I had to explicitly add what you call "marketing speak" to plainly explain why IMO pimpl is important. I had to address numerous "why bother" dismissing comments. What you call "marketing speak" I call an architectural view of a project. IMO it's quite different from developer's view that you seem to favor. All views are important... and all of them IMO need to be mentioned to cater for and to convince different readers. Surely, you (as a developer) is free to skip the "marketing speak". Somebody else (an architect and code-reviewer) might decide to skip other bits. No drama. Does it make sense? > The separation between the public interface in a hpp and the template > specialization in a cpp. I think the motivating example should > clearly show what part of the code goes where. Isn't what I did in third and fourth chapters? That said, I'll never be able to write the way you (or somebody else) like it. So, if you feel really strongly about it, please feel free to re-write it as you feel proper and submit. I am more than happy to consider and take others help. Unfortunately, that'll reverse our positions as I (and potential reviewers) might be saying "nuh, not enough "marketing speak" and such. No pressure... but that's an option to shape it up to your liking. > * Namespace: > While the alias is good, I think the whole code should be moved to > boost::, and the detail to boost::detail::impl_ptr::. > I am sort of guessing this will come up in the review. > I might be interested to help with that and submit the renaming PR if > you are open to that. 1) I do agree that the "whole code should be moved to boost::"... when it is part of Boost. Currently it is not. Currently I am on the earliest stage of gathering interest and waiting for "endorsement" and the review manager. 2) As I think I mentioned before impl_ptr is not part of any namespace by design... because the way proxy and implementation are connected, the specialization of impl_ptr<>::implementation. As I also mentioned it is IMO only a "problem" for "purists" but not for "practitioners" as from outside it is all kosher and accessed via boost::impl_ptr. You might be interested in searching for "Pimpl Again?" thread on this list for prev. discussions. Still, it you know a way around it and willing to submit your suggestions, I am certainly open for and most welcome it. But just to state the obvious -- as you do not like every line of code/doc that I write -- that goes both ways.

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[beast] Post-review follow up (RE: chunk-encoding) NEEDS YOU!
by Vinnie Falco 11 Sep '17

11 Sep '17

During the formal review for Beast, a valid point was raised that the facilities for interacting with the chunks which make up a chunk-encoded was insufficient for some use-cases. I added more interfaces to addresses the use-cases but I never got feedback from the stakeholders about the design. It is now September 10th, and the "pencils down" deadline for making changes to Beast ahead of the 1.66.0 scheduled release is October 25th. As I have not gotten any feedback, I am asking the community if there is anyone out there who would like to review the new chunk-encoding facilities. As of yet, no one in the wild has used them. Or if they have, I did not hear of it. This is the documentation for the chunking: <http://www.boost.org/doc/libs/master/libs/beast/doc/html/beast/using_http/c…> Repository: <https://github.com/boostorg/beast> Any feedback is appreciated. Thanks

1 0

Fit review - viboes
by Vicente J. Botet Escriba 10 Sep '17

10 Sep '17

Hi, here it is my review. I believe that Boost.Fit should be*accepted*. *Design* The design is sound and clean. I have some concerns respect the the ConstFunctionObjects that I believe should merit an explanation on a rationale section. Why the library support only Const function objects? Wondering if some parts should be moved to Boost.TypeTraits or reused from there (is_callable). I'm missing the std::invoke function. The_adaptor<> are not documented. The utility of those classes is not documented. If the user can use those classes the documentaion must document them. I guess they are useful to build other adaptors. It is not clear whether the defined functions would use SFINAE or just fail when used with types that don't respect the requirements. While I'm generally for SFINAE, I understand that it will not be the case in order to improve the compile time. It is not clear if the functions can be final function objects or not. *Implementation* Not seen in depth. It should use as much as possible Boost.Config and/or Boost.Predef Possible files contains details that could be shared in Boost or used from other Boost libraries https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/move.hpp - I believe Hana use something like this also to reduce the dependencies (compile footprint) https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/forward.… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/noexcept… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/and.hpp - I believe Hana use something like this also to reduce the dependencies (compile footprint) https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/compress… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/constexp… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/intrinsi… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/pp.hpp https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/remove_r… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/result_o… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/static_c… https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/detail/using.hpp It uses a lot of macros that make complex the understanding of what is behind. On the same file https://github.com/pfultz2/Fit/blob/boost/include/boost/fit/compose.hpp and only on 169 lines BOOST_FIT_INHERIT_CONSTRUCTOR, BOOST_FIT_RETURNS_CLASS, BOOST_FIT_SFINAE_RESULT, BOOST_FIT_MANGLE_CAST, BOOST_FIT_DECLARE_STATIC_VAR, BOOST_FIT_NOEXCEPT_CONSTRUCTIBLE, BOOST_FIT_ENABLE_IF_CONSTRUCTIBLE, BOOST_FIT_JOIN *Documentation* Quite good butthe description of the semantic of the provided functions would need some extra wording. Maybe a section that states that the semantic expression is part of the constraints on the types. It takes too much pages to see what the library proposes. For some functions we would need more information, examples. See below the detailed *Potential usefulness of the library* Very useful. *Did you try to use the library? With which compiler(s)? Did you have any problems?*** Not tried yet. *How much effort did you put into your evaluation? A glance? A quick reading? In-depth study?*** In-depth study of the documentation (about 5 h for this revision). *Are you knowledgeable about the problem domain?* In general, yes. *Were the concerns from the March 2016 review of Fit addressed?*** I believe ;-) Best, Vicente *Documentation:* In general: * Navigation only from the top of the page * Hyper links missing. * There is no link to real code from the examples. In particular: *http://pfultz2.github.io/Fit/doc/html/doc/src/gettingstarted.html* An explanation of the BOOST_FIT_LIFT limitations would be more than welcome. Typo: last right parenthesis in // Pipable sum BOOST_FIT_STATIC_LAMBDA_FUNCTION(sum) = pipable([](auto x, auto y) { return x + y; }); It is not clear if the following is correct in the body of a function autosum = pipable([](auto x, auto y) { return x + y; }; *http://pfultz2.github.io/Fit/doc/html/doc/src/example_print.html* I would suggest to use an heterogeneous tuple in the for_each_tupleexample. In addition use some kind of brackets to print the sequences and the tuples would help to identify what is been printed. *http://pfultz2.github.io/Fit/doc/html/doc/src/example_overloading.html* Typo: Before // Check that T has member function for operator* and ope After // Check that T has member function for operator* and opeerator-> I'm not sure the example is_derreferenceable is fair. *http://pfultz2.github.io/Fit/doc/html/doc/src/example_polymorphic_constructors.html* Maybe it is worth adding references to the proposals (P0318R0 and P0338R2) *http://pfultz2.github.io/Fit/doc/html/doc/src/more_examples.html* Extension Methods It is not clear what numbers, filter and transform are in the example. I believe that the range proposal woul include the pipe operator. My question is how both pipe operator overloads interact. http://pfultz2.github.io/Fit/doc/html/doc/src/point_free.html typo Before |b(f)(x, y)| |after| ||by(f)(x, y)|| *http://pfultz2.github.io/Fit/doc/html/doc/src/definitions.html* It woul dbe great to have an example associated to each definition Static Function Adaptor I would say "It has an additional requirement that the *class****function* is |DefaultConstructible|:" Decorator I would say "The *resulting* Function Adaptor <http://pfultz2.github.io/Fit/doc/html/doc/src/definitions.html#function-ada…> may be an unspecified or private type." Typo? Some parts of the documentation provides *http://pfultz2.github.io/Fit/doc/html/doc/src/concepts.html* ConstFunctionObject I would like to note that this concept is not representable using the Concept TS as it is quantifying universally on the Ts (args) parameters. The same applies to UnaryFunctionObject, BinaryFunctionObject Wondering if the documentation should use the term Concepts then. The use of expresion "Is an object with ..." is confusing. What are we qualifying the type or the instance? Maybe it is worth defining FunctionObject. EvaluatableFunctionObject It is not clear why this kind of FunctionObjects is useful Callable I believe we have moved to call this Invocable in the standard. But again, I believe that you want to quantify universally the arguments, isn't it? Does your definition of INVOKE differs from the one on the standard? If yes, the differences should be mentioned. If not, the definition on the standard should be referenced. You use type T twice with different meaning "The type |T| satisfies |Callable| if" "if |f| is a pointer to member function of class |T|:" I believe that here the T are not the same. Are final function objects Callable, ConstCallable? ConstCallable The brief description is the same as the one for Callable Is the definition of the second INVOKE different from the first one? UnaryCallable The name doesn't convey that it is *Const*Callable Metafunction and MetafunctionClass it is not clear what those are, there is no brief description. I guess that this applies to f. What do you mean by a type or a template? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/by.html* It is not clear to me what by(p)(xs...) == p(xs)... mean An example of `fit::by` without a function argument will be welcome. It is not clear how by_adaptor<Projection, F> and by_adaptor<Projection> can be used by the user? Shouldn't those be hidden? This is a genral remak, why F must be ConstCallable? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/compose.html *The requirements don't state clearly the constraints on the input parameters of f and the result of g, except by the semantic expression. This is a general remark. I suspect that you mean the semantic expression must be well formed. But, is this SFINAE friendly or is this a requirement? Can both function be final function objects? **** *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/conditional.html* It is not clear what king of parameters this function could have (in particular in comparison with P0051). Does it accept function/data members pointers, final classes, references_wrappers, ...? Typo "Proposal for C++ Proposal for" P0051 original proposal uses overload_linearly/overload (as Boost.Hana) instead of conditional/match. Wondering if those names aren't more clear. Why do we need to change the Boost.Hana names? There is also std::conditional :( Can more than 2 parameters be final function objects? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/flip.html** * IIUC, F must not be BinaryCallable, but Callable with at least two arguments. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/implicit.html* Is implicit a StaticFunctionAdaptor? Shouldn't StaticFunctionAdaptors have Functions as parameters? I named the `auto_cast` function `explicitly` to do a explicit conversion. Other uses of this pattern I've see are to create a buffer able to store a specific struct struct S; S* ptr = create_msg(); create_msg returns an class that is convertible to a T* and that allocates sizeof(T) bytes of memory. Why this pattern respect the DRY principle (we don't repeat S), I believe it abuses of implicit conversions. Anyway, I wanted just to share another use case for implicit. http://pfultz2.github.io/Fit/doc/html/include/boost/fit/indirect.html Wondering if it could be worth adding some preconditions as I guess that the function call indirect(f)(xs...) will be undefined if f is null *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/infix.html** * One of the asked infix operations is pow. However we would like to evaluate from right to left and have the higher precedence than * x pow ypow z===pow(x, pow(y,z)) x * ypow z===x * pow(y,z) x pow y* z===pow(x,y) * zWith the proposed infix notation this should be written x <pow> (y<pow> z)===x * pow(y,z) x * (y<pow> z)===x * pow(y,z) (x <pow> y)* z===pow(x,y) * z and the following would be surprising x <pow> y<pow> z===pow(pow(x, y, z) x * y<pow> z===pow(x * y, z) x <pow> y*z===pow(x, y * z) It would work better for swap or compare (proposed operator <=>) as these functions are not associative. I believe a note should prevent the users for such bad use cases, for which it is better to don't define the infix operator. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/lazy.html* Note p0356r1. It would be good to have a comparison in order either to improve the proposal or your library. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/match.html* Same comments than for fit::conditional. What are ex typo "Proposal for C++ Proposal for" Can more than 2 parameters be final function objects? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/mutable.html *Example of bad usage would be welcome.**Why Fit uses always const? **Why not use a reference to the function object instead? Is there a safe way to use MutableFunctionObjects with Fit? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/partial.html* Are there any constraints on the type of xs. Shouldn't them be MoveConstructibles? http://pfultz2.github.io/Fit/doc/html/include/boost/fit/pipable.html Are there any constraints on the type of x. Shouldn't it be MoveConstructible? http://pfultz2.github.io/Fit/doc/html/include/boost/fit/protect.html It is not clear to me what this useful for. Could you elaborate? Is there a typo here assert(lazy(f)(protect(lazy(g)(_1)))() == f(lazy(g)(_1))) ^ Shouldn't it be assert(lazy(f)(protect(lazy(g)),_1)() == f(lazy(g)(_1))) *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/result.html*** This adaptor converts explicitly the result of the call to the type. Have you considered `convert_to`? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html* as_failures, with_failures, .... /adaptors/ don't appear on the index. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reverse_fold.html* reverse_fold is not right fold, as right fold is right associative, isn't it? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/rotate.html*** Could you show a concrete use case? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/static.html*** What are the differences of this adaptor and the macro STATIC_FUNCTION? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack.html* Why name it unpack instead of apply like in C++17? Need to introduce the Sequence concept and how it is customized? unpack_sequence? How unpack_sequence is used by unpack? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/unpack_sequence.html*** Why unpack_sequence, and not the tuple-like traits? Is unpack_sequence defined if the class defines the tuple-like traits? Aside the example, it is not defined what the user must define. What the member function apply must return? How the unpack_sequence parameter and the Sequence parameter of member function apply are related? I don't understand template<class F, class Sequence> constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS ( s(std::forward<F>(f)) ); Is a Sequence a callable taking a Callable or there is a type here? Is there a missing return? I suspect it should be template<class F, class Sequence> constexpr static auto apply(F&& f, Sequence&& s) BOOST_FIT_RETURNS ( std::forward<F>(f)(s0, ,, sk); ); If this is correct, does it means that unpack just forwards to unpack_sequence? Does the default specialization make use of INVOKE? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/capture.html*** Please, could you show how it is more flexible than lambda captures in C++? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/if.html* What happens when the parameter is false_type? SFINAE? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/limit.html*** if a function object is overloaded with 2 and 3 parameters, would limit be useful or it is only useful when the number of parameters is fixed? I believe this is answered in http://pfultz2.github.io/Fit/doc/html/doc/src/partialfunctions.html, however I believe it merits a clarification here. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat.html* Add requirement on the function parameter that must be a Unary function such that f(f(x)) is well formed. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/repeat_while.html* The same here. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/arg.html*** What is the rational for the choice of been 1-based? Could you add a rationale in the doc? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/construct.html* Maybe add a reference to the factory proposal p03382. What happens when the parameter is not a T is not constructible from the params? SFINAE? What happens when the parameter is not a MetafunctionClass? SFINAE? I believe Boost.Hana uses make instead of construct. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/decay.html* Why not decay_copy? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/identity.html *is identity a function or a function object? do we need identity()(x)? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html*** Wondering if it is not better to locate them in a placeholders namespace, so that we can avoid possible collisions with other placeholders. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/placeholders.html#unamed-placeholder* The same here *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/function_param_limit.html*** |function_param_limit is not a Metafunction. "|The|function_param_limit| metafunction ..." *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/is_callable.html*** F must be Callable can not be a requirement ;-) Add reference to C++17 trait is_invocable. Wondering if we should have it in type_traits, if not already there. *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/apply.html*** Confusion with std::apply. is this related to std::invoke? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/function.html* "By default, all functions defined with|BOOST_FIT_STATIC_FUNCTION| use thereveal <http://pfultz2.github.io/Fit/doc/html/include/boost/fit/reveal.html> adaptor to improve error messages." How to change this default? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/lift.html*** WhyBOOST_FIT_LIFT_CLASSdoesn't defines a instance as do BOOST_FIT_STATIC_FUNCTION? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/pack.html*** How this is related with fit::capture? *http://pfultz2.github.io/Fit/doc/html/include/boost/fit/tap.html* How this is related to the tee unix command? *http://pfultz2.github.io/Fit/doc/html/doc/src/configurations.html***Which ones?

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How to deal with unused variable with a BOOST_ASSERT check?
by James E. King, III 10 Sep '17

10 Sep '17

In serialization (boost/archive/iterators/mb_from_wchar.hpp) there is some code that generates a warning on release builds. We're always striving for warning-free code in all cases. Here's the snippet: std::codecvt_base::result r = m_codecvt_facet.out( m_mbs, & value, & value + 1, wend, m_buffer, m_buffer + sizeof(m_buffer), bend ); BOOST_ASSERT(std::codecvt_base::ok == r); Normally I'd say one should always check the result and throw an exception instead of relying on an assert. I'm sure consumers would like that more. That said, is there another macro that would allow me to change the code to do something like this? BOOST_ASSERT_ASSIGN_OR_IGNORE(std::codecvt_base::result r) m_codecvt_facet.out( m_mbs, & value, & value + 1, wend, m_buffer, m_buffer + sizeof(m_buffer), bend ); BOOST_ASSERT(std::codecvt_base::ok == r); where BOOST_ASSERT_ASSIGN_OR_IGNORE would expand to, assuming BOOST_ASSERT_ACTIVE is an indicator whether assert code is compiled in: #if BOOST_ASSERT_ACTIVE std::codecvt_base::result r = #else (void) #endif This would allow me to eliminate the warning without submitting a PR that changes the behavior of the code. If something like this does not exist, would it be useful for me to add it to boostorg/assert, or would folks recommend against encouraging this behavior and instead change it to use exceptions? Thanks, Jim

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range/concepts.hpp broken on master
by Peter Dimov 09 Sep '17

09 Sep '17

Trying to, f.ex., build quickbook on master fails with an error like ./boost/range/concepts.hpp: In destructor 'boost::range_detail::SinglePassIteratorConcept<Iterator>::~SinglePassIteratorConcept()': ./boost/range/concepts.hpp:167:55: error: 'iterator_traits' in namespace 'boost::detail' does not name a type That's because boost/iterator/iterator_concepts.hpp used to include boost/detail/iterator.hpp, and no longer does since this commit: https://github.com/boostorg/iterator/commit/0107df44ab3ab41c46b616c9c37c30f… This apparently works on develop, which means that it's probably fixed in Range's develop branch, but the changes aren't in master.

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[build] using nvcc as toolset target?
by Oliver Kowalke 09 Sep '17

09 Sep '17

Hello, a grep over the boost.config showed some code related to nvcc - but I could not figure out how to use nvcc together with b2. What is the toolset target for nvcc ('b2 toolset=nvcc' doesn't work)? Oliver

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Why is the boost documentation so bad?
by Florian Lindner 08 Sep '17

08 Sep '17

Hello, I really love to use boost libraries in my project, but I always wonder, for such an accomplished project, why is the documentation so bad? A few examples: I want to get familiar with http://www.boost.org/doc/libs/1_65_1/libs/ptr_container/. What do I need to include? Neiter the tutorial, the reference or the usage guidelines mention a #include line. This is something which stroke me quite often at various boost libs. Also with the ptr_container lib, I want to find the refrence for the ptr_vector::insert function. I got to scan the reference pages of all members of it's class hierarchy to find the insert() function (it's in ptr_sequence_adapter). References and example code often have no syntax highlightning and no linking and it's extremely hard to find documentation for a specific symbol, or from there, to jump to the source code. I would really like to have a more uniform and a documentation that not feels like a annotated source code dump. I use doxygen for my own projects and I know it can generate nicely looking, with syntax highlightning and linked documentation. Please, don't take this offensive, it's just some feedback I wanted to give a long time. Best, Florian

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[release] 1.66.0 open for merging
by Daniel James 08 Sep '17

08 Sep '17

The master branch is open for merging all stable changes from develop, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging does not require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html Release schedule explanation: https://github.com/boostorg/boost/wiki/Release-Schedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Boost Release Team

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Re: [boost] (no subject)
by degski 08 Sep '17

08 Sep '17

On 7 September 2017 at 17:37, Pranam Lashkari <plashkari628(a)gmail.com> wrote: > Hello, > > I recently joined boost community. I am an engineering student from India. > I don't have much experience with contributing in open source. > > Can you please help me getting started with it? > > From where I can/should start contributing this community..? > > Thank you. > Hi Pranam, You have to write to the boost mailing list: boost(a)lists.boost.org (and ask there) See also http://www.boost.org/community/groups.html for some "rules and regulations" and the need for "subscription". You can find the archives (old posts) here: https://lists.boost.org/ Archives/boost/ In the archive you'll see that your question has been asked (many times) before, answers where to start are also given in the follow-up to those questions. Personally, I would like to see Boost.Pool being brought up to the current C++ standard (C++17). That would be a nice little project. I believe Edward Diener is the current curator of that particular library. See you on the list and have a good day (and don't forget to subscribe), degski -- "*Ihre sogenannte Religion wirkt bloß wie ein Opiat reizend, betäubend, Schmerzen aus Schwäche stillend.*" - Novalis 1798

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[gsoc] Change in Google Summer of Code admin
by Niall Douglas 07 Sep '17

07 Sep '17

Dear all, Google Summer of Code 2017 has ended with another successful summer of student coding with probably the highest calibre year we've ever seen. After four years as lead admin for Boost Summer of Code, my time has come to an end. I'll be making way for David Bellot, long time mentor at Boost GSoC and maintainer of Boost.uBLAS. Please join me in welcoming David as new lead admin. I'll be staying on as backup admin next summer to help David settle in. My time as Boost Summer of Code admin has certainly been eventful with lots of surprises, ups and downs. The fact these surprises did not turn into crises is due in large part to a few people in particular who went far beyond the call of duty: * Jon Kalb, who went to bat for the students repeatedly in multiple venues and finding tens of thousands of dollars when it was needed. * Boris Schäling, whom I replaced as lead admin and who acted as backup admin for some years, who also managed to arrange tens of thousands of dollars of sponsorship when it was needed most. * Bryce Adelstein Lelbach, for acting as backup admin these past few years. * Andrew Sutton, the lead GSoC admin before Boris, who gave such detailed and useful early advice and materials on how to best navigate the treacherous waters of Google Summer of Code! And finally to all the mentors who so generously volunteered their time, and to the students every single one of whom successfully finished their projects in my time as admin despite problems with sickness, deaths in close family etc. Some of those students have gone on to become mainstays of the C++ conference circuit, famous names in their own right. I'm sure they would have been so without Google Summer of Code, but I'd like to think that it helped bring them to Boost rather than them getting into C++ via elsewhere. Thank you students! Regards, Niall

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master and develop branches
by James E. King, III 07 Sep '17

07 Sep '17

Could someone point me to documentation on management of the master and develop branches for committers? boostorg/uuid master ends at Jan 11. boostorg/develop has a bunch of stuff in it starting on August 3, 2017. Who is responsible for merging develop into master and when should that happen? Some of the issues are already marked resolved with a milestone of 1.66.0 but they are not in master, only develop. Should pull requests on github go directly into master? I find it confusing to have both and would prefer if there was only one possible destination for pull requests on github. If there are two, someone has to keep one of them updated and that isn't very efficient. Thanks, Jim

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Libraries maintained by CMT?
by James E. King, III 07 Sep '17

07 Sep '17

Hello, I was wondering if there's a page/location that lists the libraries currently being maintained by the community maintainer team? I recently assumed responsibility for maintaining boost::uuid and I was wondering if there was a list that needs to be modified. Thanks, - Jim

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[release] Boost 1.65.1
by Daniel James 07 Sep '17

07 Sep '17

Release 1.65.1 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 bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/history/version_1_65_1.html> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.65.1/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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Appveyor and Travis CI for pull requests
by James E. King, III 07 Sep '17

07 Sep '17

Some of the repositories have Appveyor and Travis CI build configuration files in them. I don't see this translating into automatic builds on top of each pull request. I'd like to get the uuid library to the point where a pull request builds on Appveyor and on Travis, so that it is easier to validate the code changes are okay. Could someone let me know if this is possible and if so, how? Thanks, Jim

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[pool] variadically templated object_pool.construct()
by degski 07 Sep '17

07 Sep '17

I would like to request to bring object_pool.hpp up-to-date (all the way to 2011) and include a member function with this signature: template<typename ... Args> element_type * construct( Args && ... args_ ); degski -- "*Ihre sogenannte Religion wirkt bloß wie ein Opiat reizend, betäubend, Schmerzen aus Schwäche stillend.*" - Novalis 1798

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[1.65.1] Release tomorrow
by Daniel James 06 Sep '17

06 Sep '17

Hi, I'm planning on releasing tomorrow. I've written up some release notes: http://www.boost.org/users/history/in_progress.html Let me know if you want any changes to them. Daniel

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[stacktrace] Not working on Cygwin
by Phil Bouchard 06 Sep '17

06 Sep '17

Hi, I tried stacktrace on Cygwin and after tweaking some local and system headers I was able to compile libboost_stacktrace_windbg.a and libboost_stacktrace_addr2line.a but when I run my application calls to boost::stacktrace::stacktrace(1, 1) doesn't output anything. It works fine under Linux using libboost_stacktrace_backtrace.a. Thanks in advance for your help, -Phil

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Upcoming Boost.Fit Review (September 8th-17th)
by Matt Calabrese 05 Sep '17

05 Sep '17

Hi everyone, This coming Friday, September 8th, marks the start of review of the Fit library by Paul Fultz II. Source: https://github.com/pfultz2/Fit Docs: http://fit.readthedocs.org/ This is the second time that the library will go through the review process, with the previous time being in March of 2016. The result of the initial review can be found here: https://lists.boost.org/Archives/boost/2016/04/228770.php In this second review, those who choose to participate should be as rigorous as they'd be in any other review, but are also encouraged to voice whether or not the concerns from March of 2016 were addressed. The following is a brief description of the library from its author: ========== Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects, which can solve many problems with much simpler constructs than whats traditionally been done with metaprogramming. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both constexpr initialization and constexpr evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: - Function Adaptors and Decorators: These enhance functions with additional capability. - Functions: These return functions that achieve a specific purpose. - Utilities: These are general utilities that are useful when defining or using functions. ========== Requirements¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#requirements> This requires a C++11 compiler. There are no third-party dependencies. This has been tested on clang 3.5-3.8, gcc 4.6-6.2, and Visual Studio 2015. Gcc 5.1 is not supported at all, however, gcc 5.4 is supported. Contexpr support¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#contexpr-support> Both MSVC and gcc 4.6 have limited constexpr support due to many bugs in the implementation of constexpr. However, constexpr initialization of functions is supported when using the FIT_STATIC_FUNCTION <http://fit.readthedocs.io/en/latest/doc/src/FIT_STATIC_FUNCTION> and FIT_STATIC_LAMBDA_FUNCTION <http://fit.readthedocs.io/en/latest/doc/src/FIT_STATIC_LAMBDA_FUNCTION> constructs. Noexcept support¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#noexcept-support> On older compilers such as gcc 4.6 and gcc 4.7, noexcept is not used due to many bugs in the implementation. Also, most compilers don’t support deducing noexcept with member function pointers. Only newer versions of gcc(4.9 and later) support this. ========== Please take this time to become familiar with the Fit library before the review takes place and feel free to respond in this thread with any additional questions related to the library or its review. Thanks! -- -Matt Calabrese

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Boost.TR1 silently removed with 1.65?
by Tim Rakowski 04 Sep '17

04 Sep '17

Hi, I noticed that boost 1.65 does not contain the tr1 folder and found that the documentation was updated accordingly: http://www.boost.org/doc/libs/1_64_0/ contains http://www.boost.org/doc/libs/1_64_0/libs/tr1/, while http://www.boost.org/doc/libs/1_65_0/ has no http://www.boost.org/doc/libs/1_65_0/libs/tr1/. But http://www.boost.org/users/history/version_1_65_0.html <http://www.boost.org/users/history/version_1_65_0.htmldoes> does not mention this. Even if it was deprecated, shouldn't this be mentioned somewhere? Googling "site:https://lists.boost.org/Archives/boost/ 1.65 tr1" didn't yield anything either :/ Regards, Tim

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