October 2018 - Boost - lists.boost.org

CMake Announcement from Boost Steering Committee
by Jon Kalb 13 Aug '24

13 Aug '24

The libraries produced by the Boost community have had a greater impact on the way that the C++ community writes code than any other library implementation. The focus of the Boost community will always be on the libraries, but it is undeniable that we are dependent on and often limited by the infrastructure of our trade. Years ago, the move to Git was contentious; yet, it was required to improve development. In a similar vein our build system has become an impediment for many developers and users, existing and prospective. Therefore, we, the Steering Committee, announce to the Boost community our desire and intent to move Boost’s build system to CMake for users and developers alike. We are soliciting comments and proposals from the community to guide the process and the goals. Our desire is that the community can come to consensus by the end of the calendar year with a vision of supporting users and developers. We understand that the actual process of achieving the end goal will be long, time consuming, and not without its share of conflict. We also recognize that the Boost community is comprised of bright and passionate individuals that are eager to get involved and help get work done. The members of the Steering Committee have been encouraged by the discussions and activity surrounding CMake on the mailing lists over the years and know that many people have voiced visions. We hope that each of you rejoins the discussion to support this initiative and contributes to the common goal of improving Boost’s integration into the broader C++ ecosystem. For the Boost Steering Committee, Jon Kalb, Chair jonkalb(a)boost.org

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[asio][coroutine] forbid_suspend blocks
by Vinícius dos Santos Oliveira 07 Aug '19

07 Aug '19

I've implemented a dumb linter using Python + clang API that allows you to mark certain blocks as “atomic in respect to coroutines” using C++11 attributes. Usage example follows: void f() { int yield; g(yield); [[bt::forbid_suspend]] { // Comment this call to make linter accept the code g(yield); t(); } } You can change bt::forbid_suspend to another identifier by tuning settings on the beginning of the script. The prefix forbid was inspired by Rust's linters[1] as you cannot disallow the linter from inside the forbid_suspend block. Some limitations follow: - A suspend point is identified by looking references to any id equals to yield in the last argument passed to function calls. It means that yield[ignored_ec] and alike will be correctly identified, but it needs to be named yield and it needs to be the last argument to the function call. - I haven't found a way to extract attributes related to COMPOUND_STMT nodes with clang API, so I manually look for token gaps and do a simple regex. It means you cannot use macros to [[bt::forbid_suspend]] as the macro won't be expanded. - You better call the script with '-x c++' and also ' -I/usr/lib/clang/5.0.1/include'. Like I've said in the beginning of the email, it's a *dumb* linter, which means it doesn't try to handle all cases. Therefore, I don't hope to do many changes to it or maintain it to work against newer releases of clang and I'm only uploading it to gist (not fullblow Github): < https://gist.github.com/vinipsmaker2/d930fbe5b7597432b021effe618da171>. It should also be easy to hack as it is very small. I'm releasing the linter under public domain. Enjoy. I have been using fibers in a daily basis on the last months of my job to solve networking problems on a gateway project. Some of the technologies I use are: - Boost.Asio and its spawn function. - A few custom synchronization primitives for the fibers (e.g. mutex, semaphore). - Eventually I'll have to write a custom spawn function that returns a joinable handle so I can kill the usage of a fiber::barrier in a few places. I've been using the linter for about a week already and looks fine. My use case are: - To prevent iterator invalidation in regions accessing shared variables. - To guarantee events order in algorithms that handle races (cannot yield while task YYY hasn't finished). The project I use it in is not an open source project, so I cannot talk much more about it. Also, I don't claim my solution is original. I wouldn't be surprised if the very same solution exists in the wild (please let me know if you know of a similar approach). This is not a new problem. It is know for some time. For instance, in P0171, Gor Nishanov noted this same problem: “In coroutines the suspend point is clearly marked with await, which tells the reader that something unusual happens in this function and allows the reader, for example, to confirm whether the lifetimes of the objects of interest align with the lifetime of the coroutine or not, whether some locks need to be acquired to protect some concurrently accessed data, and whether some locks need to be released before the execution reaches the suspend point.” — <http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0171r0.html>, 2015 However, the solution he presented was to manually examine whole blocks of code without help from the compiler. I argue that the solution he presented is as error-prone as manually looking for exit paths that don't free acquired resources in languages lacking RAII. And I've been spoiled too much by RAII. Furthermore, I take this comment of his with highly suspicious look: “Since we are on the subject of maintenance nightmares, we would like to offer a conjecture that the absence of the await in P0114 is a likely source of many maintenance nightmares. Without a syntactic marker to signal to the person reading the code that something funny is going on, it is impossible to tell whether the following code is correct or not” — http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0171r0.html If I had to give a vote to the proposal he was defending or Chris' proposal, I'd probably have chosen Chris'. [1] https://doc.rust-lang.org/reference/attributes.html# lint-check-attributes -- Vinícius dos Santos Oliveira https://vinipsmaker.github.io/

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Non-ASCII Path Names in Repo
by Tom Kent 25 May '19

25 May '19

In the last few days we've had a non-ASCII path name added to the repo: tools/boostdep/test/utf8-test-ßµ™∃ Which came with commit 8893d1c57951a [1] I noticed this because a python 2 script (calling shutil.copytree) I had running on windows that copied the repo around started to fail. I've long needed to update that script to python 3, and am working on this. However, I wanted to point this out to the list so we could discuss if there are any other ramifications of having a non-ascii path. I vaguely remember some discussion about something like this in the past, but couldn't find it via search. If this is already a settled topic, that's great. Tom [1] https://github.com/boostorg/boostdep/commit/8893d1c57951a4a83705ed203005576…

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Re: [boost] [ Interest? ] [ out_ptr ] Tiny C++ Abstraction for C-Style Output Pointers
by Bjorn Reese 12 May '19

12 May '19

On 06/28/18 21:03, ThePhD via Boost wrote: > out_ptr is a small abstraction for making types such as > std::unique_ptr, std::shared_ptr, boost::shared_ptr, and the upcoming > std::retain_ptr > <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0468r0.html> work > work C-Style output functions as a parameter, addressing the need of > wanting to be able to do "my_c_api_init( foo, bar, &my_smart_ptr );". It's Does out_ptr have other use-cases than C interoperability?

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[test] unit test command-line handling
by Stefan Seefeld 22 Mar '19

22 Mar '19

Hello, this is a question concerning the Boost.Test framework. I'd like to pass command-line arguments to my tests, and I'm unsure of how to proceed. I have found https://www.boost.org/doc/libs/1_68_0/libs/test/doc/html/boost_test/adv_sce…, which shows how to access the command-line programmatically, but that's declared obsolete, and it's also lacking some important info, such as how I should handle the argv vector. Are there any examples that demonstrate this use case ? Specifically: * What (non-deprecated) API can I use to access command-line arguments during test initialization ? * How does my own handling of command-line arguments interact with Boost.Test's own command-line argument handling ? Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

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Reminder: 1.69 closes for major changes Wednesday
by Marshall Clow 10 Dec '18

10 Dec '18

Upcoming dates: * 31-Oct: Boost 1.69.0 closed for major code changes * 7-Nov: Boost 1.69.0 closed for beta * 14-Nov: Boost 1.69.0 beta 1 * 5-Dec: Boost 1.69.0 closed for release * 12-Dec: Boost 1.69.0 release -- The Boost Release Team

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clang-win, (Thin)LTO this time
by degski 08 Nov '18

08 Nov '18

Starting new thread. Substantial progress has been made towards the goal of compiling Boost with Clang/LLVM (clang-cl.exe, targeting MSVC). The latest PR in this respect by Peter has achieved this. The next step is to be also able to use lld (lld-link in case of clang-cl.exe targeting MSVC) to generate the Boost-libs (static/dynamic). The main interest, IMO, is to be able to use LTO (Thin or Full), which is not possible without the use of LLD. A secondary benefit appears to be faster link times (info from the lld manual). In order to build static ThinLTO-enabled libs, it suffices to pass <compileflags>-flto=thin in the project jam file. The archiving, though, needs to be done with lld-link.exe, passing /lib as the first option (this way it will act as lib.exe, while being able to handle the llvm-byte-code [lib.exe finds the so generated .obj-files to be corrupt]). At consumption time of the libs, lld-link needs to be used for linking. Hacking clang-win.jam:156 to: toolset.flags clang-win.archive .LD $(cond) : "\"C:\\Program Files\\LLVM\\bin\\lld-link.exe\"" /lib ; achieves this goal. I would like to ask (probably Peter) to have a look into whether this can be achieved "the proper way", i.e. to programmatically set that particular line to the required value for this use-case. degski -- *“If something cannot go on forever, it will stop" - Herbert Stein*

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"peer reviewed" - Rights and responsibilities of maintainers
by Alexander Grund 07 Nov '18

07 Nov '18

I'm having trouble with a maintainer of a boost library over a PR and am seeking for clarification. Background (may be skipped): A bug was introduced into the library which I noticed in one of "my" (company) projects leading to a reproducible crash. However the scenario is not that common (although others have the same problem) so it wasn't noticed earlier. I analyzed the problem and created a minimum working example to reproduce this and then opened a PR with a fix. The maintainer did not comment on this for multiple months so given it IS complicated, I factored out additional PRs with tests I created to show the problem, so each PR is fairly small. In the result there were PRs with tests that failed on travis and the fix-PR which included the test-PRs and the fix and succeeded on travis (and all other CIs) and users reported success using this PR. Still no response from the maintainer on any PR. He then added an own test claiming to be enough, while I (as the author of the original tests) knew it wasn't as e.g. it didn't fail. (so what's it worth then?) Furthermore he added a commit changing unrelated stuff and ADDITIONALLY changing code I touched in the fix claiming that it would be the essence of my patch and fix the problems. Again I (as the author of the original patch) know that this is not true especially as the test-PRs still fail with his patch applied. So my point/problem is: Is the maintainer allowed to simply do changes as he wishes without any review at all? My expected procedure is: - Someone creates a PR - Maintainer (and optionally the community) reviews (and comments on) it - It eventually gets merged or rejected with comments why OR: - Someones else (including the maintainer) creates a contra-PR fixing the same problem - That author explains, how and why this fixes the same problem and why it is superior to the original PR - This gets reviewed and either PR gets merged Arguments were made, that this doesn't apply to accepted boost libraries as e.g. "it's [the maintainers] heads that got chopped off if something gets broken". I would challenge this by the simple example at hand: This boost library IS broken and it crashes MY application (and others). But I see no heads rolling. Furthermore: If the maintainer is allowed to patch and change as he wants without ANY review, how can Boost still be called "peer reviewed"? My trust in Boost stems from the extensive review a library has to undergo before it is included in Boost. If afterwards no review is happening or reviews are actively avoided (as in the current example), then the older a Boost library gets, the less trust I would have in it as more and more unreviewed changes get included. So again: What is the Boost course on reviews of existing libraries and the statement on the rights and responsibilities of maintainers? Thanks, Alexander Grund

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[testing] Lots of spurious test runners
by John Maddock 05 Nov '18

05 Nov '18

There are rather a lot of test runners that fail all tests due to setup errors: sandia-gcc-5.4.0-c++11 cc1plus: error: unrecognized command line option "-std=c++11" sandia-gcc-5.4.0-c++14 cc1plus: error: unrecognized command line option "-std=c++14" sandia-gcc-6.4.0-c++11 cc1plus: error: unrecognized command line option "-std=c++11" sandia-gcc-6.4.0-c++14 cc1plus: error: unrecognized command line option "-std=c++14" sandia-intel-16.0-c++11 /bin/sh: line 1: icpc: command not found sandia-intel-16.0-c++14 /bin/sh: line 1: icpc: command not found sandia-intel-16.0 /bin/sh: line 1: icpc: command not found sandia-intel-17.0-c++11 /bin/sh: line 1: icpc: command not found sandia-intel-17.0-c++14 /bin/sh: line 1: icpc: command not found sandia-intel-17.0 /bin/sh: line 1: icpc: command not found teeks99-02-dc3.1-11-Docker-64on64 /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/functional:2194:2: error: no type named 'type' in 'std::enable_if<false, void>' (and more errors from <functional> - the compiler appears to be unable to handle the std lib headers so I'm not sure what the point of testing it is?) igaztanaga-develop-gcc-3.4c++03 cc1plus.exe: error: unrecognized command line option "-fvisibility-inlines-hidden" cc1plus.exe: error: unrecognized command line option "-fvisibility=hidden" Best, John. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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interest in a flag library
by Masse Nicolas 05 Nov '18

05 Nov '18

Hi all, This is the first time I post on this mailing list :). I'm posting because i'd like to know if people would be interested in a library to treat enum types as flags. I find that's something which is lacking in the language since the introduction of strongly typed enums, and I've since written some code in order to do this. So far I've seen some discussion on this mailing list about that, but it doesn't seems that any library have been written yet. So do you think it is worth the effort of porting and documenting my code so that it can integrated into boost, or not? Regards, Masse Nicolas. PS: For those interested, the code consists of a flag class, and overloads operators like '|' or &. It can be used like this: enum struct option : uint { none = 0, first = 1, second = 2, third = 4, forth = 8 }; static constexpr flags<option> var1 = option::first; static constexpr flags<option> var2 = option::second | option::third; static constexpr auto var3 = var1 | var2; /* type will be resolved into flags<option> */ static constexpr auto var4 = option::first | option::second | option::third; /* works too */ int main() { std::cout << var1 << std::endl; std::cout << static_cast<uint>(var2) << std::endl; /* note that static_cast<int> won't compile since the underlying type is uint */ std::cout << (var3 & option::forth) << std::endl; std::cout << (var3 == var4) << std::endl; return 0; }

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Draft copy - Call for Submissions - CMake for Boost
by Robert Ramey 05 Nov '18

05 Nov '18

The following is a draft of the document of I have planned to post on behalf of Boost on or around 1 November 2018 as the first step in our next attempt to accommodate CMake in Boost. Robert Ramey Call for Submissions - CMake for Boost ====================================== For some time, there has been interest on many users and developers of Boost Libraries to make Boost easier to use with CMake. Discussions in the past have not resulted in an implementation which has been widely accepted. Never the less, hope springs eternal, and we intend to attempt this once again. It seems that often there are difficulties before such projects even start in that there are wide discrepancies as to what should be the goals and expectations of Boost support of CMake. The aim of this document is to try to build a consensus on this question before encouraging CMake developers and experts to submit proposals for Boost support of CMake. Requirements and Scope ====================== Requirements ------------ Submissions will fulfill the applicable requirements of any boost submission. This will include: a) any necessary code. b) specifications/requirements for things like directory structure and contents. b) A useful document. Document should provide information, examples and templates so that a typical C++ and CMake user should be able to do any of the following in a short time - say 10 minutes. Document at a minimum should be viewable as html and/or PDF file. 1) A library user should be able to incorporate a Boost Library into the CMake script. 2) A library user should be able to determine which additional Boost Libraries he needs. 3) A library developer should find it simple to create the requisite CMake files for his library. Thus the documentation should contain explanation and perhaps other means such as examples and/or "templates" for required CMake files. c) test of CMake facilities supported by the CMake implementation. This will include code, test of any features, capabilities that the submission provides. Users expect that if they follow the instructions in the documentation, they will get the promised results. A manner of proving this must be provided. A likely response to this requirement would be a "test project" which can be used to demonstrate that the submission actually works. This will be useful in the future for maintenance of the CMake Boost implementation. It will permit the maintainer of the Boost.CMake facility to work on and test their fixes and improvements without disrupting other developers and users. d) a Boost License Facilities and features ----------------------- CMake as it stands has lots of capabilities. But it has a fair amount of complexity as well. Lots of things can be accomplished in multiple different ways - each with subtly different results and effects. CMake for Boost will likely consist of documentation, examples, CMake code, and other stuff to use CMake to permit new features and facilities for users and developers of Boost libraries. What follows is a list of facilities that Boost users and developers would like to acquire with CMake for Boost. Those marked with * should be considered hard requirements. That is, submissions which don't include this feature can't be considered. Other items are interesting and would be considered if included in a submission. *a) incorporating selected Boost Libraries into a user's application *b) incorporating selected Boost Libraries into a user's library c) building a boost library d) building a boost tool such as Boost.bcp, Boost.boostdep, etc. e) testing a boost library - if testing of Boost libraries is to be supported, the following features should be considered. Those marked * should be considered essential. *1) execution tests - must pass/ must fail *2) compile only tests - must pass/ must fail *3) link only tests - must pass/ must fail 4) should be available to both users and developers 5) should not depend upon tools other than C++. 6) test should have the option of posting the results to some public "dashboard" 7) option for recursive testing and/or building of libraries might be nice. That is if library A uses library B and I test library A, this would automatically test library B beforehand. *f) In CMake, dependent libraries are specified as part of the library CMakeLists.txt files. There several ways to do this and the subject is pretty confusing to get right. Any submission documentation has to explain to library developers how do this. g) Some have suggested a highly automated process including downloading/updating, finding other components on other machines, etc. This shouldn't be considered h) packaging - preparation of distributable, installable files for various operating systems. That is support for the CPack facility. i) There has been a lot interest and work in automatically determining dependencies It's a much deeper subject than most people realize. Solving this problem is not a requirement of the submission. However, submitters are free to address this if they desire. *j) support of library modularity. This would mean: *1) independence of things outside the library directory structure. To wit - no presumption about any "super project". *2) building out of tree *3) no need for installing libraries not used by the build target k) ... Submission Rules and Procedures ------------------------------- a) This document constitutes a "Request for Submissions". It will be announced on the boost announcements list, boost developer's list, slack/boost, isocpp website and twitter account, reddit at r/cpp. Submissions will be open to anyone. b) Submissions will be accepted at an email address to be specified. Received submissions will receive a "prescreening" to determine that they meet the requirements specified for such submissions at the top of this document. Those that don't will be returned to the author. c) The name of the author of a submission will not be included in the submission. Authors will be expected to take reasonable efforts to maintain his anonymity via a github repo without a real name assigned, anonymous, email address etc. We understand that the nature of the submission and debate during subsequent review of the proposals. Never the less we believe that anonymity can be mostly maintained. The the true identity of the author of the selected proposal will not be revealed until the selection is made. The motivation for this anonymity is to attract submitters who find the boost review process distressing, annoying and/or unpleasant. It should also address the concerns of those who beleive that by not being a "boost insider" they won't get fair consideration. Boost is first and foremost a meritocracy. We seek the very best in everything regardless of other considerations. d) Submissions will be closed on or about 1 February 2019. Boost formal review will commence shortly there after. Depending on the number of submissions received, the process may last as long as month. e) As per the boost formal review rules and customs, some time after the review period terminates, the review manager will announce the review results. This will likely contain some conditions regarding alterations required in the submissions implementations. I the author find these too onerous, and declines the opportunity to integrate his submission as an official part of boost, the review manager may select an alternate submission. It's also possible that the review manager may decide to accept none of the submissions. f) when the submission is integrated into boost and is shown fulfill the requirements stipulated by the review manager. The author will receive a "prize" of $5000 and a large but cheap medal on a ribbon hopefully to be awarded at the next C++Now (Boost Con). As this is written, this prize is subject to finding a funding source. It's understood that this stipend is in no way compensation, for all the work and aggravation of this task. But we hope that it will serve as a tangible token of our gratitude for solving one of Boosts most pressing and difficult problems. Useful Resources =============== “Effective CMake" - https://www.youtube.com/watch?v=bsXLMQ6WgIk https://gist.github.com/mbinna/c61dbb39bca0e4fb7d1f73b0d66a4fd1 https://github.com/purpleKarrot/Boost.CMake https://steveire.wordpress.com/2016/08/21/boost-dependencies-and-bcp/

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clang-win, again
by Peter Dimov 31 Oct '18

31 Oct '18

Has anyone succeeded in getting clang-cl.exe working under b2? I've installed llvm-6.0.1, added it to PATH, put using clang-win : : : <compatibility>vc14 ; in my user-config, and what I get is: C:\boost-git\develop\libs\smart_ptr\test>b2 toolset=clang-win sp_interlocked_test warning: mismatched versions of Boost.Build engine and core warning: Boost.Build engine (b2) is 2015.07.00 warning: Boost.Build core (at C:/boost-git/develop/tools/build/src) is 2018.02-git C:/boost-git/develop/tools/build/src/tools\msvc.jam:1087: in set-setup-command *** argument error * rule virtual-target.from-file ( file : file-loc : project ) * called with: ( : /C:/boost-git/develop/libs/smart_ptr/test : object(project-t arget)@129 ) * missing argument file C:/boost-git/develop/tools/build/src/build\virtual-target.jam:970:see definition of rule 'virtual-target.from-file' being called C:/boost-git/develop/tools/build/src/tools\msvc.jam:652: in clang-win.compile.c+ + C:/boost-git/develop/tools/build/src/kernel\modules.jam:107: in modules.call-in C:/boost-git/develop/tools/build/src/util\indirect.jam:105: in indirect.call C:/boost-git/develop/tools/build/src/build\virtual-target.jam:902: in execute C:/boost-git/develop/tools/build/src/build\virtual-target.jam:821: in class@acti on.actualize C:/boost-git/develop/tools/build/src/build\virtual-target.jam:332: in actualize- action C:/boost-git/develop/tools/build/src/build\virtual-target.jam:518: in actualize- no-scanner C:/boost-git/develop/tools/build/src/build\virtual-target.jam:142: in class@virt ual-target.actualize C:/boost-git/develop/tools/build/src/build\configure.jam:258: in try-find-build C:/boost-git/develop/tools/build/src/build\configure.jam:396: in find-builds-raw C:/boost-git/develop/tools/build/src/build\configure.jam:455: in configure.find- builds C:/boost-git/develop\boostcpp.jam:734: in boostcpp.deduce-address-model C:/boost-git/develop/tools/build/src/kernel\modules.jam:107: in modules.call-in C:/boost-git/develop/tools/build/src/util\indirect.jam:105: in indirect.call C:/boost-git/develop/tools/build/src/build\property.jam:144: in property.evaluat e-conditionals-in-context C:/boost-git/develop/tools/build/src/build\targets.jam:1087: in evaluate-require ments C:/boost-git/develop/tools/build/src/build\targets.jam:1121: in common-propertie s2 C:/boost-git/develop/tools/build/src/build\targets.jam:1017: in targets.common-p roperties C:/boost-git/develop/tools/build/src/build\targets.jam:1313: in class@basic-targ et.generate C:/boost-git/develop/tools/build/src/build\targets.jam:812: in generate-really C:/boost-git/develop/tools/build/src/build\targets.jam:784: in class@main-target .generate C:/boost-git/develop/tools/build/src\build-system.jam:797: in load C:\boost-git\develop\tools\build\src/kernel\modules.jam:295: in import C:\boost-git\develop\tools\build\src/kernel/bootstrap.jam:139: in boost-build C:\boost-git\develop\boost-build.jam:17: in module scope

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[property-tree] state of the library, fixes and extensions
by Goehring, Christian 31 Oct '18

31 Oct '18

Hi @all, the property-tree lib seems to be in some sort of dormant state judging from the repository activity. Is this library still actively maintained (for example, the xml-functionality would need some support for CData)? Do you know if there is any need for extensions (for example JSON-support) or did some other alternative succeed this library? Thanks in advance! Best, Christian

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questions regarding visibility and b2
by Robert Ramey 30 Oct '18

30 Oct '18

I've got a few questions about the "visibility" changes for boost. My understanding is that "visibility" for gcc and clang are "sort of the same thing" as dll import and export are for windows. Now we've made "visibility" the "default". But this seems kind of weird. This has been made a b2 feature. In order to run tests, this feature is applied to the b2 command line. What's weird is that it's applied to the tests/executables and propogated down to libraries which are built. I actually don't know what "visibility" means in the context of building and executable. If I want to use visibility=global then on the library build, it needs to be applied to everything. It's very weird and doesn't seem in line with the windows solution. Heretofore, I've applied visibility to the library build "by hand" by adding the appropriate command line switches to the right places. I'm aware that this is not the b2 way. But the b2 way doesn't seem to make sense to me. On the bright side, changing default visibility didn't seem to have any effect on the serialization library other than on one test. Unfortunately, turning this confused a pending issue and made it even more contentious than it already is/was. FWIW - this is not so much the fault of b2 or anyone in particular. The use of DLLS/shared libraries is the triumph of development over design by vendors, each of whom do their own thing and have never been able to get it together. By now this has created enough technical debt that it will take years to straighten out if people actually start to address it, which no one seems interest in doing. Anyway, the b2 approach is pretty confusing and probably wrong. I'm also guessing that, as one would predict, a change like this is going to provoke subtle failures in lots of small corners which will take quite a while to discover. I'm not sure how to address this. Robert Ramey

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[release] 1.69.0 deadline for new libraries approaching
by Marshall Clow 29 Oct '18

29 Oct '18

It's that time again! On Wednesday, the master branch will be closed for adding new libraries. Upcoming dates: * 24-Oct: Boost 1.69.0 closed for new libraries and breaking changes * 31-Oct: Boost 1.69.0 closed for major code changes * 7-Nov: Boost 1.69.0 closed for beta * 14-Nov: Boost 1.69.0 beta 1 * 5-Dec: Boost 1.69.0 closed for release * 12-Dec: Boost 1.69.0 release -- The Boost Release Team

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Is boost supported on z/os
by Naveen Sharma 28 Oct '18

28 Oct '18

Hello Does boost supported on z/os or may be subset of library. We are planning to replace our current library with boost. One of the platform we support is z/os and so I am researching if boost can be compiled and usable on the platform. I did searched on the internet but did not get much information. Before I dive into it, I thought to ask. Thanks Naveen

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Re: [boost] [histogram] Objections against switch to C++14?
by Bjorn Reese 28 Oct '18

28 Oct '18

On 10/22/18 6:42 PM, Hans Dembinski wrote: > Do you object against raising the requirement from C++11 to C++14 for the implementation of boost.histogram? No objection from my side. However, you may consider making parts of the library available to C++11 users, because there are plenty of those out there.

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Builds from boost/status fail early?
by James E. King III 27 Oct '18

27 Oct '18

Using develop from this morning (tried various combinations of these three options...): boost@d48d3305d4b4:/boost/status$ ../b2 toolset=clang variant=release cxxstd=03 ... /boost/tools/build/src/build/feature.jam:491: in validate-value-string from module feature error: "shared:" is not a known value of feature <link> error: legal values: "shared" "static" /boost/tools/build/src/build/feature.jam:365: in expand-subfeatures-aux from module feature /boost/tools/build/src/build/feature.jam:422: in expand-subfeatures from module feature /boost/tools/build/src/build/feature.jam:871: in feature.expand from module feature /boost/tools/build/src/build/targets.jam:1103: in evaluate-requirements from module targets /boost/tools/build/src/build/targets.jam:1121: in common-properties2 from module targets /boost/tools/build/src/build/targets.jam:1017: in targets.common-properties from module targets /boost/tools/build/src/build/targets.jam:1313: in class(a)basic-target.generate from module object(typed-target)@47912 /boost/tools/build/src/build/targets.jam:812: in generate-really from module object(main-target)@70272 /boost/tools/build/src/build/targets.jam:784: in class(a)main-target.generate from module object(main-target)@70272 /boost/tools/build/src/build/targets.jam:273: in class(a)project-target.generate from module object(project-target)@47307 /boost/tools/build/src/build/targets.jam:273: in class(a)project-target.generate from module object(project-target)@4568 /boost/tools/build/src/build-system.jam:797: in load from module build-system /boost/tools/build/src/kernel/modules.jam:295: in import from module modules /boost/tools/build/src/kernel/bootstrap.jam:139: in boost-build from module /boost/boost-build.jam:17: in module scope from module

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[statechart] visibility change broke things
by James E. King III 27 Oct '18

27 Oct '18

Boost.StateChart wasn't building on a regular basis. It looks like the visibility changes broke it. I opened an issue for it. I also changed Travis CI to build it monthly.

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[serialization] boost:array
by Yuval Lifshitz 27 Oct '18

27 Oct '18

Any idea on why was the serializer for boost:array removed?Can we re-introduce it? Yuval Lifshitz

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Fwd: Syntax highlighting for Boost.Jam language in Visual Studio Code
by Mateusz Loskot 27 Oct '18

27 Oct '18

I've announced this on boost-build but I think folks here may find it useful as well. Mat ---------- Forwarded message --------- From: Mateusz Loskot <mateusz(a)loskot.net> Date: Fri, 26 Oct 2018, 23:18 Subject: Syntax highlighting for Boost.Jam language in Visual Studio Code To: <boost-build(a)lists.boost.org> Hi, (A pet project warning!) I've published an extension for VSCode with a brave attempt to color-hightlight syntax of Jam language: https://github.com/mloskot/vscode-boost-jam This is based on a very basic TextMate language grammar definitions, often naive, and, by no means, it is complete or bug-free coverage of the Jam. Even so, I think it quite helps to de-annoy or even enjoy process of writing Jam scrips :-) I'm no expert of writing TextMate language grammars - this is my first ever attempt - so chances are I may be incapable of fixing bugs or improving it with advanced features. Especially, that "the process of writing a TextMate language grammar remains poorly documented" - http://www.apeth.com/nonblog/stories/textmatebundle.html Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Mailman upgrade
by Brad Johnson 27 Oct '18

27 Oct '18

Happy Late October all. Just a quick notification that mailman upgraded from 2.1.26 -> 2.1.29 at 27-Oct-2018 02:50 UTC. Release notes for 2.1.27, 2.1.28, and 2.1.29: https://launchpad.net/mailman/2.1/2.1.27 https://launchpad.net/mailman/2.1/2.1.28 https://launchpad.net/mailman/2.1/2.1.29 Sanity checks on test mailing list shows mail is still flowing and archiving. Any questions or concerns, please let me know at this address or sysadmin(a)boost.org. Thanks, -- Brad Johnson Ciere Consulting 916.877.6030 brad.johnson(a)ciere.com ciere.com

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[parameter_python] Merge to master
by Edward Diener 26 Oct '18

26 Oct '18

I would like to merge parameter_python to 'master' from 'develop'. Does anybody see anything wrong with this ? This fixes using Python 3+ with parameter as well as Python 2+, among other things.

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Library devs only: Boost v2.x distro design questions
by Niall Douglas 26 Oct '18

26 Oct '18

Splitting this off from the other thread, can I get feedback from Boost library maintainers ONLY. Not users, not non-maintainers. Q0: Are you willing to do the work to adapt your library for any Boost v2.x distro if it were to happen? Q1: Would you prefer a new, separate Boost v2.x distro in parallel to the v1.x distro, or to keep everything within one v1.x distro? Q2: Would you be intending to keep your library inside Boost v1.x, move it exclusively to Boost v2.x, or have it exist in both Boost v1.x and v2.x but with different defaults configured? Also, would the version in v1.x be hard forked from any v2.x edition i.e. the v1.x edition would get orphaned? Q3: What C++ standard should Boost v2.x's master build system be defaulted to? C++ 11, 14, 17 or 20? Q4: Should Boost v2.x use a boost2 namespace, or namespace boost { inline namespace v2 { }}? (This affects whether Boost v2 and v1 editions of your library can be used within the same translation unit) Q5: What master buildsystem should Boost v2.x use? Boost.Build, cmake, Build2, something else? Q6: Should Boost v2.x's libraries auto integrate individually into some package manager? If so, which ones do you intend to support? Q7: Should Boost v2.x have official release versions done by release managers, or should it be a rolling release of "whatever last passed the CI @ 100%"? Note that you can have this, and have official release versions of "especially known good" editions too. Q8: Should Boost v2.x use a local HTML server to serve documentation, and the static HTML docs be dispensed with as a requirement? Q9: What are your feelings towards the use of Python to script infrastructure and tooling in any Boost v2.x? For example, Python to run a local HTML server to serve documentation locally, or Python to build a release etc Q10: What parts of core Boost are you utterly dependent upon, and would absolutely need ported to any Boost v2.x as no STL alternatives exist? I could go on, but let's stop there for now. Niall

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[histogram] Objections against switch to C++14?
by Hans Dembinski 26 Oct '18

26 Oct '18

Dear reviewers of boost.histogram, thank you again for your reviews. I am currently working on the issues raised during the review and some of the requested features would be easier to implement when the library standard is raised from C++11 to C++14. This only affects the implementation side, not the user side. It would make my life easier and the implementation code more readable, because I can emulate `if constexpr` using in-place generic lambdas instead of out-of-place functors in the detail namespace. To make the library more user-friendly, I have to do more and more of these emulated `if constexpr`. Do you object against raising the requirement from C++11 to C++14 for the implementation of boost.histogram? Best regards, Hans

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