- Boost - lists.preview.boost.org

[test] How to execute shell commands
by Mike Dev 28 Sep '18

28 Sep '18

Does the boost unit test frame work provide a way to write a test that executes a couple of shell commands? Specifically, I want to write a test that compiles a cmake project: https://github.com/boostorg/vmd/pull/4 https://github.com/boostorg/preprocessor/pull/20 what I need to do for that is essentially (on Linux): - mkdir <build_dir> - cd <build_dir> - cmake <source_dir> - cmake --build . Of course I can write a cpp program that uses std::system to execute those commands but I was wondering if there was a more direct way to do it. Best Mike

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contract work
by Ggh 28 Sep '18

28 Sep '18

Hi, Sorry to pollute but: Available for contract work, code samples here: http://www.multi.fi/~ghaga/bak1 Cheers Greg

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stufff
by Ggh 28 Sep '18

28 Sep '18

I don't know what I am up to: http://www.multi.fi/~ghaga/bak1/ http://www.multi.fi/~ghaga/ Thank you, Greg

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Re: [boost] [cmake] Pull request announcement
by Bjorn Reese 28 Sep '18

28 Sep '18

On 09/14/18 13:44, Mike Dev via Boost wrote: > This will not address > - Testing [...] > In short: all the difficult stuff is left out ;) > The goal is not to present a solution that can replace b2 but to have > a minimal starting point upon which individual library authors or the > community as a whole can make iterative improvements. If and when BCM > (or an alternative) is accepted into boost, individual libraries can > then easily switch to this full-fledged solution and of course any > author can create a more complete CMake solution for his library at > any time (as some already have). In my experience, we want to have both an integration and standalone CMake file. This split is necessary to avoid problems with multiple instances of enable_testing() when using one library from another. * The integration file builds only what is necessary for integration into other projects. This is similar to what you are proposing. * The standalone file builds everything including test and documentation. This reuses the integration file to build the library itself. If we place your proposed CMake file in the library root, and dependent libraries start using that location, then it becomes difficult to later have the standalone CMake file in the library root, which is the more natural choice. So we should be cautious about where we place these files.

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Formal Review of Proposed Boost.Histogram Library Starts TODAY
by Mateusz Loskot 27 Sep '18

27 Sep '18

Dear Boost Community, The formal review of Hans Dembinski's Histogram library starts TODAY, the September 17th, and lasts until September 26th, unless an extension occurs. =========== What is it? =========== Histogram is a header-only C++11 library, provides multi-dimensional histogram template class for counting, statistics and data exploration. The histogram class interface has been carefully designed to make the library * offer simple and convenient default behaviour * easy to learn and safe to use * convenient to use for one- as well as multi-dimensional analysis * compatible with STL algorithms * dependant only on C++11 standard library and optionally on Boost The author followed the "Don't pay for what you don't use" principle. The histogram class is customisable through policy classes, but the default policies were carefully crafted so that most users do not need to customize anything. The default policies guarantee the histogram to be safe to use as a black box, memory efficient, and very fast, where safety is related to overflow prevention and large values capping. This guarantees is one of unique features of the library in comparison to other implementations. The histogram class comes in two variants, which share a common interface: * static variant is optimised at compile-time to provide maximum performance, at the cost of reduced runtime flexibility and potentially larger executables; * dynamic variant is a bit slower, but configurable at run-time. Both variants of the histogram class provide optional serialization support implemented with Boost.Serialization. The library itself is header-only and the tests as well as examples can be built using both, Boost.Build and CMake. There are no dependencies required other than C++11 compiler. Optional dependencies include the GNU Scientific Library (GSL) and the ROOT framework from CERN which are needed the corresponding speed test programs used for performance comparison. A note on history: The library was first announced to the Boost community in May, 2016 [1] and the author received extensive feedback. Then, after a year of work posted second request for comments in April, 2017 [2]. =================== Getting the library =================== Checkout the `master` branch from the library git repository: https://github.com/HDembinski/histogram/ NOTE: The author follows the library submission process [3]: the master branch remains frozen for the period of the formal review, modifications in response to feedback should go to `develop` branch and big items may be worked and discussed via opening an issue on GitHub. Documentation: http://hdembinski.github.io/histogram/doc/html/ Website: http://hdembinski.github.io/histogram/ ================ Writing a review ================ Please, follow the official Boost formal review procedure [4]. If you feel this is an interesting library, then please submit your review to the Boost developer list (preferably), or the review manager to mateusz (at) loskot (dot) net. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. If needed, refer to the Boost Library Requirements and Guidelines [5]. Please, give constructive criticism! [1] https://lists.boost.org/Archives/boost/2016/05/229389.php [2] https://lists.boost.org/Archives/boost/2017/04/234410.php [3] https://www.boost.org/development/submissions.html#Review [4] https://www.boost.org/community/reviews.html [5] https://www.boost.org/development/requirements.html Mateusz Review Manager for the proposed Boost.Histogram -- Mateusz Loskot, http://mateusz.loskot.net

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[GitHelp] release version of boost from GitHub?
by Kostiantyn Ponomarenko 26 Sep '18

26 Sep '18

Hi, guys. What is the right place for getting the last/or-any (released) version of boost? This page provides the last release as well as others: https://www.boost.org. But I've got the impression that after Boost moved to GitHub and became "modular", the releases can be downloaded right from the GitHub "releases" page. So it looks like it is not the case, and my assumptions is wrong because when I go to the "releases" page on GitHub (https://github.com/boostorg/boost/releases) and download a release (let's say "boost-1.68.0") I don't get any libs inside. Could you please help me to understand this situation. Is the only place to get a release of boost is https://www.boost.org, but not GitHub? Is GitHub used only for development, or getting the latest changes which are not released yet? --- Kostia Kyiv, Ukraine

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Formal Review of Proposed Boost.Histogram Library - LAST DAY
by Mateusz Loskot 26 Sep '18

26 Sep '18

Dear Boost Community, According to the review schedule, the formal review of Hans Dembinski's Histogram library lasts until the end of TODAY. Please, anyone who is aiming to post a review, hurry up! If there are members who have planned to post a review and still wish to do it but require more time, please speak up now indicating how much time you'd need. [1] https://www.boost.org/community/review_schedule.html Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Making Boost invisible
by John Maddock 25 Sep '18

25 Sep '18

Folks I have a bug report against Boost.Config that I don't know what (if anything) I should do about: https://github.com/boostorg/config/issues/243 The issue is this: lets say I build boost as static libraries with -fvisibilty=hidden because I want my application or shared library to *hide all boost symbols*. But there are some parts of boost which unconditionally make things visible - throw_exception is one particular culprit, but there are others, probably anything which uses BOOST_SYMBOL_VISIBLE in fact. Question: should we support this? If so how? The only thing I can think of is a user-defined macro which when set, disables symbol visibility. Thoughts? Thanks, John. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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Re: [boost] Formal Review of Proposed Boost.Histogram Library Starts TODAY
by Klemens David Morgenstern 25 Sep '18

25 Sep '18

- What is your evaluation of the design? The design is excellent, in that is geared towards readability and performance. - What is your evaluation of the implementation? It looks highly optimized with a focus on only being as cheap as possible on CPU. I.e. only pay for what you use. - What is your evaluation of the documentation? Detailed, good examples, I understood everything. - What is your evaluation of the potential usefulness of the library? It's not my domain, but for anyone interested in data analysis this seems super useful. I think there should be more libraries from that domain, even tough it's not my primary one. - Did you try to use the library? With what compiler? Did you have any problems? Yes, I did last year, when it was still in development, I used MinGW 5 and MSVC 2017. No problems. - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I looked into the library in depth last year and gave the author my feedback on several implementation details. - Are you knowledgeable about the problem domain? Not in depth, but I know the basics. And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Yes, definitely.

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Interest in Unicode library for Boost?
by Zach Laine 23 Sep '18

23 Sep '18

I've been working on a Unicode library for submission to Boost, with an eye toward standardizing robust Unicode support for C++. It started as a better string library for namespace "std2", with minimal Unicode support. Though "std2" may never happen, those string types are still in there, and the library has grown to also include all the Unicode features most users will ever need. You can find the Github page here: https://github.com/tzlaine/text You can find the online docs here: https://tzlaine.github.io/text If you care about portable Unicode support, or even addressing the embarrassment of being the only major production language with next to no Unicode support, please have a look and provide feedback. I gave a talk about this at C++Now in May, though it's a bit out of date, as the library was not then finished. It's three hours, so, y'know, maybe skip it. For completeness' sake: https://www.youtube.com/watch?v=944GjKxwMBo&index=7&list=PL_AKIMJc4roVSbTTf… https://www.youtube.com/watch?v=GJ2xMAqCZL8&list=PL_AKIMJc4roVSbTTfHReQTl1d… Zach

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Re: [boost] Median in Boost.Accumulators
by Lakshay Garg 23 Sep '18

23 Sep '18

On Sun, 23 Sep 2018 at 12:53, Zach Laine <whatwasthataddress(a)gmail.com> wrote: > > On Sun, Sep 23, 2018 at 2:45 PM Lakshay Garg <lakshayg373(a)gmail.com> wrote: >> >> On Sun, 23 Sep 2018 at 11:59, Zach Laine <whatwasthataddress(a)gmail.com> wrote: >> > Also, what if I don't actually call get() very often? >> >> If get() is not called very often, then I guess just using a plain vector and >> calling nth_element on it would be the best approach. >> >> > Is there any way to take advantage of make_heap()'s O(n) characteristics, >> > and avoid doing an O(n) push_heap() n times? I can't think of one offhand, >> > just curious. >> >> The complexity of push_heap is actually O(log(n)) and not O(n) > > [make.heap] says: > > Complexity: At most 3 * (last - first) comparisons. > Correct! complexity for make_heap is O(n) and complexity for push_heap is O(logn). https://en.cppreference.com/w/cpp/algorithm/make_heap https://en.cppreference.com/w/cpp/algorithm/push_heap

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Re: [boost] Median in Boost.Accumulators
by Lakshay Garg 23 Sep '18

23 Sep '18

On Sun, 23 Sep 2018 at 11:59, Zach Laine <whatwasthataddress(a)gmail.com> wrote: > > On Sun, Sep 23, 2018 at 10:59 AM Lakshay Garg <lakshayg373(a)gmail.com> wrote: >> >> On Sun, 23 Sep 2018 at 08:39, Zach Laine via Boost >> <boost(a)lists.boost.org> wrote: >> > >> > Could you compare and contrast this with the standard library's way of >> > computing a median, std::nth_element()? Yout just give it N/2 for 'n', and >> > it computes the median. >> >> The reason for not using std::nth_element was because I wanted >> to be able to query the median at any point of the sequence very >> efficiently. Had I used std::nth_element, I would have needed O(n) >> time for obtaining the median. For a case where I need to compute >> median after every single element, this would have required O(n^2) >> time for a sequence of length n. Here is my implementation in case >> you would like to have a look: >> >> https://gist.github.com/lakshayg/d27f29b4634cbfea3fc48c21b7b608ef > > I missed that the first time, thanks. > > Your implementation does not seem to support a windowed working set > (one element at a time is added and the oldest one removed). Is that right? Yes, that is correct. This approach does not support a window. > Also, what if I don't actually call get() very often? If get() is not called very often, then I guess just using a plain vector and calling nth_element on it would be the best approach. > Is there any way to take advantage of make_heap()'s O(n) characteristics, > and avoid doing an O(n) push_heap() n times? I can't think of one offhand, > just curious. The complexity of push_heap is actually O(log(n)) and not O(n)

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Re: [boost] Median in Boost.Accumulators
by Bjorn Reese 23 Sep '18

23 Sep '18

On 09/23/18 04:21, Lakshay Garg via Boost wrote: > I rolled up my custom implementation of the algorithm and > used it for my project. I wanted to check if people on > this list might be interested in such an implementation > for Boost.Accumulators in which case I can try to adapt my > implementation and send a PR. Boost.Accumulators does not seem to be actively maintained. > Performance characteristics: For a stream of n numbers, the > memory required is O(n). Median can be queried at any point > of time in O(1) and adding all the elements costs O(nlog(n)) Sounds like you keep two ordered lists (e.g. std::set) of equal size. Then the median is the first element in the second list.

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Formal Review of Proposed Boost.Histogram Library is HALFWAY through
by Mateusz Loskot 22 Sep '18

22 Sep '18

Dear Boost Community, We've reach half-way through the formal review of Hans Dembinski's Histogram library. The review lasts until the end of September 26th. If you are interested in applications for mathematics, statistics graphics, image analysis, and such, or in the Histogram library itself, please consider reviewing the Histogram library by the end of September 26th. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[filesystem] Library maintainers needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Filesystem needs one or more maintainers. This is a high complexity library, further complicated by (1) requiring both Windows and non-Windows implementation code and (2) needing a major upgrade for compatibility with the new standard library version shipped in C++17. Furthermore, there are constant Pull Requests and Issues that arise, and these almost invariably take a lot of time for the maintainer to process. My personal opinion is that Boost should deprecate the Boost library in favor of the standard library implementations, and do only minimal maintenance for several years until most users have migrated to C++17 or later. But that's up to the new maintainers to decide. Thanks, --Beman

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[endian] Library maintainer needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Endian needs a maintainer. This is a low/medium complexity library that requires only minor effort to maintain. --Beman

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[timer] Library maintainer needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Timer needs a maintainer. This is a simple low complexity library, and requires little effort to effort to maintain. --Beman

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[build][testing] Tests naming in Jamfile
by Mateusz Loskot 21 Sep '18

21 Sep '18

Hi, I'm updating Jamfile-s of Boost.GIL and it made me wondering: For example: test-suite "boost-gil-test" : [ run promote_integral.cpp ] ; Apart from replacing the deprecated test-suite with alias, I wonder what is the recommended policy of naming the test suites, are there any rules? For example, should it be more or less hierarchical boost-{lib}-{testname} {lib}-{testname} {testname} or the name is completely local to/internal in a library and library maintainers are free to name as they desire? I could not find anything in the development guidelines and the testing policy docs. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net p.s. Originally posted to boost-testing incorrectly https://lists.boost.org/boost-testing/2018/09/8446.php

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[system] A non-allocating message() overload
by Peter Dimov 20 Sep '18

20 Sep '18

One of the objections against <system_error> is that message() needs to allocate memory, because it returns an std::string. This is true even for user-defined categories that can implement it without allocating, with a static message table. To address this, I'm thinking of adding the following overload to boost::system::error_category (with the intent of proposing it for std::error_category): virtual char const* message( int ev, char* buffer, size_t len ) noexcept; This is modeled after the glibc-specific version of strerror_r (and in fact has the exact same signature and behavior). If the implementation has a static character literal corresponding to `ev`, it returns it directly. If not, it composes an error message into the provided buffer, then returns `buffer`. Comments?

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HoF Problems with Boost 1.68 / LLVM-Clang / Windows
by Adam Hartshorne 20 Sep '18

20 Sep '18

The following two bits of code compile ok with MSVC, but using LLVM/Clang produces the following errors. Using the code in print.cpp BOOST_HOF_STATIC_FUNCTION(simple_print) = fix(first_of( BOOST_HOF_LIFT(print_with_cout), BOOST_HOF_LIFT(print_with_range), BOOST_HOF_LIFT(print_with_tuple) )); produces the following error 1>./boost_hof_functions.h(45): error : templates cannot be declared inside of a local class 1>C:\boost_1_68_0\boost/hof/lift.hpp(90): note: expanded from macro 'BOOST_HOF_LIFT' 1>C:\boost_1_68_0\boost/hof/lift.hpp(105): note: expanded from macro 'BOOST_HOF_LIFT_CLASS' And BOOST_HOF_STATIC_LAMBDA_FUNCTION(print) = boost::hof::proj(simple_print); produces >./boost_hof_functions.h(51): error : non-const lvalue reference to type 'reveal_adaptor<...>' cannot bind to a temporary of type 'reveal_adaptor<...>' 1>C:\boost_1_68_0\boost/hof/lambda.hpp(241): note: expanded from macro 'BOOST_HOF_STATIC_LAMBDA_FUNCTION'] There are nearly identical errors with functions from in.cpp.

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"is-assignable" compile error using Boost 1.68 / LLVM-Clang / Windows
by Adam Hartshorne 20 Sep '18

20 Sep '18

I receive the following build error when switching to LLVM toolset in VS2017 to build code using Boost 1.68. The code builds fine with MSVC compiler. 1>C:\boost_1_68_0\boost/type_traits/has_trivial_move_assign.hpp(49): error : no template named 'is_assignable'; did you mean 'std::is_assignable'? 1>C:\boost_1_68_0\boost/type_traits/intrinsics.hpp(233): note: expanded from macro 'BOOST_HAS_TRIVIAL_MOVE_ASSIGN'

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Unexpected behavior in reverse lookup (asio resolver)
by LC 19 Sep '18

19 Sep '18

When performing a reverse lookup of an address: *r->async_resolve( boost::asio::ip::tcp::resolver::endpoint_type( adr, 80 ) ...* the address itself is returned (as string), when the name of the host cannot be found. I would expect an error/exception, telling me this instead. Consider the following (custom class which does both): *Resolver::resolve< ResolverClass >( &rc, "www.yahoo.com", 1 ); Resolver::resolve< ResolverClass >( &rc, "8.8.8.8", 2 ); Resolver::resolve< ResolverClass >( &rc, "none.exist.end", 3 ); Resolver::resolve< ResolverClass >( &rc, "2.18.77.109", 4 ); Resolver::resolve< ResolverClass >( &rc, "198.252.206.16", 5 ); Resolver::resolve< ResolverClass >( &rc, "234.255.173.123", 6 );* And the result: *1: hostname: www.yahoo.com, address: 87.248.98.7, error: 1: hostname: www.yahoo.com, address: 87.248.98.8, error: 2: hostname: google-public-dns-a.google.com, address: 8.8.8.8, error: 3: hostname: , address: 0.0.0.0, error: Host not found (authoritative) 4: hostname: a2-18-77-109.deploy.static.akamaitechnologies.com, address: 2.18.77.109, error: 5: hostname: stackoverflow.com, address: 198.252.206.16, error: 6: hostname: 234.255.173.123, address: 234.255.173.123, error:* 2 is looking up of "8.8.8.8", which of course can be found and returns the google.com entry. Likewise, 4 and 5 can be found and return the correct result. *Nr. 6, however, is a non-existent ip-address. As you can see, instead of an error, the address itself is returned when calling "endpoint_iterator->host_name();".* This is unexpected and (I think) undocumented. It can be easily detected by testing if host_name returns an address, but this would require another (test) conversion; as a result you'd end up with forth&back conversions. Wouldn't it be better, if the reverse lookup returned an error/exception, if the name of the host cannot be found? This would be more consistent with the "Host not found (authoritative)" error in example 3. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[cmake] Pull request announcement
by Mike Dev 18 Sep '18

18 Sep '18

Dear all, unless I'm encountering an overwhelming resistance to this idea here on the ml, I intend to create a batch of PRs that introduce minimal cmake support to a large subset of boost libraries (maybe even all). It appears that cmake efforts have yet again stalled. Last I heard was that everyone is waiting for BCM and the author of that library still tries to find a review manager. As we probably can't expect a full-fledged, boost-wide solution in the near future I'm trying it with a low-effort approach that will establish the minimal framework needed such that each library can be (where necessary) build with cmake and specify it's dependencies on other libraries (the latter being the really important part). >From that starting point a more holistic solution can then be developed step by step and (in most cases) library by library. The only fundamental thing that needs to be decided by the community is a canonical naming scheme for the cmake targets that should be used by other libraries in their `target_link_libraries` call. For that I suggest that each library should provide an alias target called Boost::<library_name> (e.g. Boost::program_options) This also follows the naming scheme provided by cmake itself when using boost libraries that are installed on the system. Now about what I'm specifically going to put into the PRs: - I'll propose a trivial, top-level cmake file be added to the boost super project that doesn't do anything but look for CMakeLists.txt files in the root folder of each library and calls that file if present - Individual libraries get a simple CMakeLists.txt file that will - create an appropriate build target - INTERFACE library for header-only - STATIC for regular libraries - create an alias named Boost::<library_name> - build the library if necessary - specifying the minimum required c++ version - specify the local include directory (iirc that will always be "include") - specify all required dependencies This will not address - Testing - Installation - Creation of shared libraries - Creation of documentation - Special provisions for IDE integration In short: all the difficult stuff is left out ;) The goal is not to present a solution that can replace b2 but to have a minimal starting point upon which individual library authors or the community as a whole can make iterative improvements. If and when BCM (or an alternative) is accepted into boost, individual libraries can then easily switch to this full-fledged solution and of course any author can create a more complete CMake solution for his library at any time (as some already have). Finally, please don't nick-pick this to death. I'd like to have a more complete solution too, but it isn't coming, so let's do the minimum we can and go on from there. Note that the advantage of such a minimal solution is also that there are very few design decisions to make that may later turn out to be wrong and then create a maintenance burden. The only things that are visible on an interface level (and thus should remain reasonable stable) are: - The alias name Boost::<library_name> - How the public dependencies are specified: target_link_libraries( boost_ foo PUBLIC Boost::config Boost::core Boost::bar ) - The position of the CMakeLists.txt file in the library root folder All of this is long established best practice. Anything else can gradually be built on top of that. Best Michael

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[config] does BOOST_ATTRIBUTE_UNUSED defined implies __attribute__((used)) exists ?
by Raffi Enficiaud 17 Sep '18

17 Sep '18

Hi, I have a problem with symbol visibility in boost.test: https://github.com/boostorg/boost/pull/190 I am wondering if __attribute__((used)) is a portable way to flag a static const ref as being used, or there are variations (__attribute__((used)) vs __attribute__((__used__))). I am also wondering if __attribute__((used)) can be considered as available if BOOST_ATTRIBUTE_UNUSED is defined. Would it make sense to have an BOOST_ATTRIBUTE_USED in boost.config? Thanks, Raffi

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[system] Do you use the deprecated features or cygwin/linux/windows_error.hpp?
by Peter Dimov 17 Sep '18

17 Sep '18

I'd like to query the Boost community as to whether certain legacy features of Boost.System are in use; namely, (1) everything guarded by BOOST_SYSTEM_ENABLE_DEPRECATED and (2) the cygwin_error.hpp, linux_error.hpp, or windows_error.hpp headers. Does anyone use these, and for what purpose? I'm thinking of dropping the deprecated features. In addition, does anyone use boost::throws()? I'm thinking of at least discouraging its use in the documentation, if not deprecating it outright.

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CMake and the Boost Steering Committee
by Edward Diener 16 Sep '18

16 Sep '18

I think it is a huge waste of time for anyone to discuss or implement a CMake solution for Boost until the Boost Steering Committee actually gets involves and defines what "Boost using CMake" actually means and gives the specifics as to what this actually entails. Otherwise nearly everything said about Boost and CMake, although well-intentioned, is just a lot of hot air and we are going absolutely nowhere trying to make any progress in this so-called direction. The Boost Steering Committee is largely at fault for saying that Boost would be using CMake, without defining what this actually means. Once again, as in our discussion about Boost dropping support for C++03, we are all wasting our time because the meaning of some language having been used is not clear and way too general to reach any meaningful conclusions. But in this case the only people who can really define what Boost using CMake actually means is the Boost Steering Committee, or someone representing the Boost Steering Committee on this mailing list, who can clarify what Boost using CMake is actually about, since it was the Boost Steering Committee who made the decision in the first place. If it is not the case that the Boost Steering Committee defines what Boost using CMake actually is supposed to mean but rather it is up to those on this mailing list to decide the issue, I would argue that Boost should focus on the simplest solution first, making Boost libraries, whether header-only or not, available for use in end-user CMake scripts in such a way that it will be easy to add this functionality for the 130 or so individual Boost libraries with the least amount of effort or work involved for each library, without arguing unduly about more complicated or more purist solutions. In other words lets start with the easiest, most practical solution, because I assure you when the smoke has cleared, 99% of those people involved in the discussion will not want to do the practical work of actual adding necessary CMake scripts to any of the 130 or so libraries involved, and even the maintainers of those libraries will not want to spend much time implementing some complicated CMake solution for their library. But I still think that without a specific definition of what Boost using CMake actually entails from the steering committee we are just wasting time and breath and to no good purpose.

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How do I test more configurations locally
by Joshua Marshall 14 Sep '18

14 Sep '18

Hello all, How do I test more configurations on my local systems rather than relying on TravisCI and AppVeyor? I've been working on fixing up BGL to pass basic TravisCI and AppVeyor tests, but it seems I have to be particularly reliant on those online tests. I'd like to have more of that done on my local system. There is probably a way to do that, but I don't know what it is.

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REMINDER: Formal Review of Histogram by Hans Dembinski
by Mateusz Loskot 14 Sep '18

14 Sep '18

Dear All, (NOTE: This is not start the review announcement yet) I'd just like to *remind* you all that the review of the Histogram library developed by Hans Dembinski is going to happen according to the schedule [1], from September 17, 2018 to Septenber 26, 2018. I will be sending the official START announcement this weekend. [1] https://www.boost.org/community/review_schedule.html Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[outcome] Change semantics on UB from peer review agreed semantics?
by Niall Douglas 14 Sep '18

14 Sep '18

Dear Boost, At https://github.com/ned14/outcome/issues/150, Andrzej has raised his desire to change Outcome's semantics on UB from what the two peer reviews here agreed to previously. As this would be a major change to interface different to what the consensus here agreed to, I am asking boost-dev to weigh in with its opinion. Status: ------- Outcome has been finished, apart from docs, since April (http://boost.2283326.n4.nabble.com/outcome-v2-1-progress-report-td4702900.h…) for the Boost and standalone variants, and since July for the experimental P1028 edition. The documentation has not been touched since the February review, but will be tackled when my current work contract ends this November, and I regain free time. Preamble: --------- Outcome has the notion of programmable "default actions" which occur when the user does something like call `.value()` on a `result<T, E>` which has an error. Let's call this "value-on-valueless". Outcome, as was approved here, has the following selector on `result<T, E>` in the Boost edition: ``` template <class T, class EC, class E> using default_policy = std::conditional_t< std::is_void<EC>::value && std::is_void<E>::value, terminate, std::conditional_t< trait::has_error_code_v<EC>, error_code_throw_as_system_error<T, EC, E>, std::conditional_t< trait::has_exception_ptr_v<EC> || trait::has_exception_ptr_v<E>, exception_ptr_rethrow<T, EC, E>, all_narrow >>>; template <class R, class S = boost::system::error_code, class NoValuePolicy = policy::default_policy<R, S, void>> using boost_result = basic_result<R, S, NoValuePolicy>; template <class R, class S = boost::system::error_code, class NoValuePolicy = policy::default_policy<R, S, void>> using result = boost_result<R, S, NoValuePolicy>; ``` So, if result's `E` is: - `void`, value-on-valueless calls `std::terminate()`. - contains an error code, value-on-valueless throws `system_error()`. - otherwise is hard undefined behaviour i.e. we tell the compiler that value-on-valueless will never happen, and the compiler doesn't even compile code for it to happen. The documentation, as was approved here, made it very clear that hard UB is the default for custom defined `E` types. See https://ned14.github.io/outcome/tutorial/default-actions/happens1/. A nice segfault usually emerges. For the standalone edition, judging from user feedback and bug reports, this hard UB behaviour is the most common intentional configuration for Outcome users. I have not received any complaints about this choice, if anything a majority has been choosing Outcome precisely *because* of this choice. Andrzej's request ----------------- Andrzej points out in https://github.com/ned14/outcome/issues/150 that it's too easy to get surprised by a small source change which causes the error code trait to no longer match the `E` type, thus flipping the code base from throwing `system_error` into hard UB unexpectedly and without warning. He wishes to change the default to failure to compile i.e. if result's `E` is: - `void`, value-on-valueless calls `std::terminate()`. - contains an error code, value-on-valueless throws `system_error()`. - otherwise a failure to compile with useful diagnostic. Users can, of course, manually specify a `NoValuePolicy` of `all_narrow` if they wish hard UB on value-on-valueless. It would be a non-trivial change from what peer review (twice) agreed, as the default would have substantially changed. What is boost-dev's opinion on this proposed change in semantics? Thanks, Niall

10 32

list.boost.org
by David Bellot 09 Sep '18

09 Sep '18

Hi, I'm looking for the person in charge of lists.boost.org, the mailing list server. We're having an issue on one of the mailing list (ublas). Cheers, David

3 2

[ublas] How to merge a PR?
by Frédéric 09 Sep '18

09 Sep '18

Hi, I submitted a PR 1 month ago. Something rather trivial. How can it be merge? https://github.com/boostorg/ublas/pull/56 Thanks, F

2 1

Re: [boost] list.boost.org
by Bjorn Reese 09 Sep '18

09 Sep '18

On 09/09/18 00:13, David Bellot via Boost wrote: > I'm looking for the person in charge of lists.boost.org, the mailing list > server. We're having an issue on one of the mailing list (ublas). https://lists.boost.org/Archives/boost/2017/02/232710.php

1 0

[all] Request for out of the box visibility support
by Antony Polukhin 09 Sep '18

09 Sep '18

I'd like to draw attention to a problem with Boost binaries for Linux. There's an awesome -fvisibility=hidden flag for Linux compilers that improves load times, performance, size of binaries and reduces the chance of symbol collisions. More info at https://gcc.gnu.org/wiki/Visibility . Unfortunately, most of the Boost libraries do not set it by default: - atomic - chrono - container - context - contract - coroutine - date_time - exception - fiber - filesystem - graph - graph_parallel - iostreams - locale - mpi - program_options - python - random - regex - signals - system - test - thread - timer - type_erasure - wave Moreover minority of the above libraries just do not work with the flag. Users just can not run ./b2 cxxflags="-fvisibility=hidden" because there's a chance that some library could stop linking. Actually things are even more ugly. Linux distributions usually do not tune the build flags for each package so at least Debian based distributions build Boost with default flags. Users get suboptimal builds. If you're a maintainer of one of the above libraries *please do* the following steps: * Make sure that all the public symbols are accordingly marked with appropriate BOOST_SYMBOL_* macro. Instruction is available here: https://www.boost.org/doc/libs/1_68_0/libs/config/doc/html/boost_config/boo… * Turn on the visibility=hidden by default: * by adding <target-os>linux:<cxxflags>"-fvisibility=hidden" to the Jamfile if you do not care much for antique compilers (Example https://github.com/boostorg/stacktrace/blob/819f2b1c861dec7530372a990ecabab… ) * by using a more advanced technique for detecting the flag availability (For example see https://github.com/boostorg/math/blob/develop/build/Jamfile.v2#L20 or https://github.com/boostorg/log/blob/develop/build/Jamfile.v2#L24 ) P.S.: I would appreciate any comments or updates on the feature request. P.P.S.: Log, Math, Serialization (and Stacktrace) libraries already use that flag by default. Many thanks! -- Best regards, Antony Polukhin

10 33

[range] #11202: boost.sort header conflicts with boost.range header
by Steven Ross 07 Sep '18

07 Sep '18

https://svn.boost.org/trac10/ticket/11202 has been sitting for years. The "using range::sort" causing the namespace pollution needs to be deleted, and then everything depending on that inside boost needs to be fixed. This will break people dependent on the namespace pollution, but that's the only way to clean it up. Is anyone willing to take on this cleanup? Is there a good way to identify cross-library dependency breakages in situations like this so they can be fixed?

10 20

Trac
by Robert Ramey 07 Sep '18

07 Sep '18

Could we agree to stop using the Trac system? The github issues/pr system is much more functional. I propose we close the trac system to new issues - be of course leave it available for reference. Robert Ramey

21 57

Guidelines on copyright notice maintenance
by Mateusz Loskot 06 Sep '18

06 Sep '18

Hi, The license guidelines [1] include instructions on "How should Boost programmers apply the license to source and header files?" Unless I've missed it, there seem to be lack of guidelines about how to maintain (existing) copyright notices. I don't aim to resurrect the old lengthy thread from Sept 2015 on validity of copyright notices. In that thread, however, some guidelines or conventions were expressed: [2] "because copyright is only claimed for changes meeting a certain threshold of originality" [3] "It's up to those people to add a line if they so decide. Copyright only covers expressions of creativity." Those suggests, there seem to be common understanding on if/how/when it is recommended or even necessary to update copyright notice in a source file of a Boost library. Wouldn't it be helpful to captured those as guidelines in the BSL FAQ. Would there be someone knowledgeable about it and willing to make the update or at least explain it here? (I will make it into HTML and PR to boostorg/website) I understand David and Beman, primary authors of the page [1], may no longer be available. [1] https://www.boost.org/users/license.html [2] https://lists.boost.org/Archives/boost/2015/09/225565.php [3] https://lists.boost.org/Archives/boost/2015/09/225570.php Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 2

[ublas] Supporting DNNs with Tensors/Multidimensional Arrays
by Cem Bassoy 06 Sep '18

06 Sep '18

Gsoc <https://summerofcode.withgoogle.com/organizations/4507228564881408/> 2018 just ended one week ago and we had many successefully completed student projects <https://github.com/BoostGSoC18>. I was responsible for adding tensor support to Boost.uBLAS for primarily supporting multilinear algebra operations in the field of numerics. The wiki description along with the implementation can be found here <https://github.com/BoostGSoC18/tensor>. Similar to Boost.multi_array <https://www.boost.org/doc/libs/1_68_0/libs/multi_array/doc/index.html> the runtime-reshapable tensor data structure is parametrized in terms of number of dimensions (rank/order), dimension extents, data type, layout (first- and last-order) and storage type. The first two are runtime-variable. I am also about to add subtensor (view/handle of a tensor) along with multidimensional iterators for convenient algorithm implementation. It is yet not as flexible as GSL's multi_span <https://github.com/Microsoft/GSL/blob/master/include/gsl/multi_span>: does not yet support static rank and dimensions. However, basic generic tensor operations (contraction/transposition/reshaping/...), including a nice syntax for Einstein's summation convention with placeholders, using C++17 features are provided. The operations are evaluated using expression templates (not smart yet). Similar to the tensor <https://eigen.tuxfamily.org/dox/unsupported/group__CXX11__Tensor__Module.ht…> framework of Eigen, that is used by tensor flow <https://github.com/tensorflow/tensorflow>, the tensor data structure in Boost.uBlas could be taken for implementing deep neural networks or higher-order statistics I think. I am not sure if the C++ community would appreciate if Boost has some form of basic operations for building *deep neural networks* (DNNs). I would like to ask 1. if it make sense for boost to support basic operations for DNNs? 2. what are the obligatory, necessary basic operations for creating DNN building blocks? 3. if there are any additional data structure parameters that needs to be added for (efficiently) supporting DNNs? Best, Cem

3 5

Schedule update request
by Antony Polukhin 06 Sep '18

06 Sep '18

Schedule at https://www.boost.org/development/index.html does not show next release dates and close of merge window. Please update it. Thanks in advance!

1 0

Assistance debugging compile time isomorphism failure to get PR #114 working
by Joshua Marshall 05 Sep '18

05 Sep '18

Hello all, Since Saturday I've been banging my head against this one. Over at https://github.com/anadon/graph/tree/isomorph-fix I've been trying to fix some of the newly enables travisCI failures. I'm getting a persistent type mismatch that may not be resolvable sanely, but I want to get another set of eyes before I just the gun and start suggesting ripping out tests.

1 0

Deprecation of detail endian macros.
by Rene Rivera 03 Sep '18

03 Sep '18

This is a general announcement that I'm deprecating the following that is part of Predef: Header: boost/detail/endian.hpp Macros: BOOST_BIG_ENDIAN, BOOST_LITTLE_ENDIAN, BOOST_PDP_ENDIAN, and BOOST_BYTE_ORDER You can use the equivalents from Predef < https://www.boost.org/doc/libs/1_68_0/doc/html/predef/reference.html#predef…> as follow: BOOST_BIG_ENDIAN == BOOST_ENDIAN_BIG_BYTE BOOST_LITTLE_ENDIAN == BOOST_ENDIAN_LITTLE_BYTE BOOST_PDP_ENDIAN == BOOST_ENDIAN_LITTLE_WORD There is no equivalent for BOOST_BYTE_ORDER. But there are no uses in Boost as far as I could tell. In the develop branch of Predef I've added a deprecation message indicating as such. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

2 1

pending vs detail headers
by James E. King III 03 Sep '18

03 Sep '18

Is there any general guidance for moving headers out of boost/pending? Do we really need to include a forwarding stub for these? I'd like to consider headers in boost/pending as "not final" and therefore we should be able to move headers out of there without leaving a forwarding stub. Example: https://github.com/boostorg/dynamic_bitset/pull/24 - Jim

5 4

No Viable function warning
by randydom 03 Sep '18

03 Sep '18

Hello i've the bellow function : __declspec(dllexport) int TrySendData(_isocket * isocket,char * ibuff,int ilen) { boost::system::error_code ignored_error; boost::asio::write(isocket->socket(), boost::asio::buffer(ibuff,ilen), boost::asio::transfer_all(), ignored_error); if(ignored_error) return 0; return 1; } I get a *No Viable function* warning , can someone tells me why or helps me in fixing this warning . Thank you . -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

Original STL Library Documentation has been recovered and is now safe forever.
by Robert Ramey 02 Sep '18

02 Sep '18

The Standard Template Library is the foundation of modern C++. The creation and publication of this code and its documentation set a new standard for the formal specification of what a computer program should do, how it should be designed and how it should be formally documented. These pages were maintained first by Silicon Graphics and then later by Hewett-Packard. In January of 2018 these pages were removed by H-P. This is a historic blunder. I have recovered the original STL Library Document and hosted them here: http://www.rrsd.com/software_development/stl/index.htm Robert Ramey

8 10

[vcpkg] Support non-Windows build. #4169
by degski 02 Sep '18

02 Sep '18

FYI: https://github.com/Microsoft/vcpkg/pull/4169#issuecomment-417867673 degki -- *“If something cannot go on forever, it will stop" - Herbert Stein* *“No, it isn’t truth. Truth isn’t truth" - Rudolph W. L. Giuliani*

1 0

[integer] CMT assume responsibility for Boost.Integer?
by James E. King III 01 Sep '18

01 Sep '18

The maintainer of Boost.Integer has no commits since 2008, and I was unable to get a hold of him by email (waited 10 days for a reply). I suggest we transfer responsibility of this repository to the CMT. - Jim

3 3

Gsoc 2019
by Shubham Verma 01 Sep '18

01 Sep '18

Hey I'm new, but I'd like to contribute to your organisation, can someone please guide me along?

5 4

Let's stop distributing binaries
by Robert Ramey 31 Aug '18

31 Aug '18

The fact is that users of boost use compilers with differing levels of C++ standard conformance. This creates a number of problems including (but probably not limited to) a) Using libraries built with different levels of C++ conformance may create ABI issues. b) it creates a discussion about "dropping C++03 support". Actually it creates a discussion about that the above actually means. c) It's motivated a suggestion that all libraries move to header only. This is not great idea - but I won't address that here. I believe all these issues - and more - would disappear if we just stopped distributing binaries. Each user would be building his own boost version with (presumably) the same compiler. Since C++03 compatible libraries are C++?? compatible, each library author can maintain the level of backward compatibility that he wishes. But if we're not going to distribute binaries, then users might as well just clone the latest "certified - good - tagged" version in the master branch from the github repo. That is, let's just stop or truncate the whole release circus. Replace with an occasional "certification/versioning procedure" which would make available a "squashed" master suitable for efficient cloning. This would make everyone's life easier. Robert Ramey

19 63

A possible date for dropping c++03 support
by Mike Dev 31 Aug '18

31 Aug '18

Sorry for all the bad line-breaks in my previous message. I don't have access to a properly configured email client right now. This should be easier to read: ====== Original Message ============== Please, let's not derail the discussion just after some consensus has emerged and just before it actually produces actionable items. Let's not make the better the enemy of the good here. I made the suggestion to commonly drop c++03 support in the hope that it would actually lead to some code simplifications and reduced coupling between the boost libraries - even if only in their implementation (if someone wanted to do a real c++14 reboot of their library, no one is/was stopping them anyway). >From the survey, I'd say interest in actually applying c++11 features in libraries that a currently supporting 03 is already relatively low, but big enough that I believe this will actually lead to some changes other than just changing the default test settings. That is with a standard almost universally supported by compilers in use today. Even though the move from 11 to 14 is much less dramatic, c++14 support is less wide spread and outside of the big three, there are many compilers where even the most recent version doesn't support c++14, so I just don't see people that are currently maintaining c++03 support in their libraries suddenly starting to use c++14. All this doesn't preclude a discussion about if and when to move to c++14 or a general policy about LTS versions and the like, but please keep it separate unless you are really, really confident it will lead to something actionable earlier than what is currently proposed. I have lots of Ideas, how boost could be reformed and/or modernized but in the end it comes down to convince the individual library maintainers to actually do something. I think the current proposal will at least spark some action. Let the announcement to move to cmake be a warning sign about realistic expectations about the evolution of boost. Maybe I'm aiming too low, but again, if you want more, please open a separate thread and most likely, whatever you come up with there will not be mutually exclusive with what is proposed here. Regarding the test settings: If c++11 is supposed to be the lowest official supported version then that is what should be tested Anything else doesn't make sense (you can't claim to support c++11 if you don't test if it actually works there). In any case, as was mentioned before, for the announcement itself we don't need give any specifics about something that is going to happen 1-1,5 years from now. How about something like " c++03 mode/compilation will no longer be tested / part off the general test/suit"? Best Mike

1 0

A possible date for dropping c++03 support
by Mike Dev 31 Aug '18

31 Aug '18

Please, let's not derail the discussion just after some consensus has emerged and just before it actually produces actionable items. Let's not make the better the enemy of the good here. I made the suggestion to commonly drop c++03 support in the hope that it would actually lead to some code simplifications and reduced coupling between the boost libraries - even if only in their implementation (if someone wanted to do a real c++14 reboot of their library, no one is/was stopping them anyway). >From the survey, Id' say interest in actually applying c++11 features in libraries that a currently supporting 03 is already relatively low, but big enough that I believe this will actually lead to some changes other than just changing the default test settings. That is with a standard almost universally supported by compilers in use today. Even though the move from 11 to 14 is much less dramatic, c++14 support is less wide spread and outside of the big three, there are many compilers where even the most recent version doesn't support c++14, so I just don't see people that are currently maintaining c++03 support in their libraries suddenly starting to use c++14. All this doesn't preclude a discussion about if and when to move to c++14 or a general policy about LTS versions and the like, but please keep it separate unless you are really, really confident it will lead to something actionable earlier than what is currently proposed. I have lots of Ideas, how boost could be reformed and/or modernized but in the end it comes down to convince the individual library maintainers to actually do something. I think the current proposal will at least spark some action. Let announcement to move to cmake be a warning sign about realistic expectations about the evolution of boost. Maybe I'm aiming too low, but again, if you want more, please open a separate thread and most likely, whatever you come up with there will not be mutually exclusive with what is proposed here. Regarding the test settings: If c++11 is supposed to be the lowest official supported version then that is what should be tested Anything else doesn't make sense (you can't claim to support c++11 if you don't test if it actually works there). In any case, as was mentioned before, for announcement itself we don't need give any specifics about something that is going to happen 1-1,5 years from now. How about something like " c++03 mode/compilation will no longer be tested / part off the general test/suit"? Best Michael

1 0

A possible date for dropping c++03 support
by Mike Dev 30 Aug '18

30 Aug '18

>From the discussion about abi compatibility when the Boost.System library is compiled e.g. in c++03 mode and then included in ac++11 project or vice versa (https://groups.google.com/forum/#!topic/boost-developers-archive/EWG5NVOZo_ g) > > When can we drop C++03 support? :D This will probably be ignored or shouted down, but maybe someone just needs to make a concrete suggestion about which people can discuss and vote so I'm giving it a shot: What about the first or second release in 2020 ? By then, all major toolchains have had solid c++11 support for at least 5 years ( I think, msvc was the last one with VS2015) and at least partial support for 7+ years (gcc 4.8, msvc 2013, clang 3.3). Also, most likely c++20 will be released in that year, which means that c++03 compatible libraries would have to support 5 different (and partial incompatible) language versions by then (not to mention ABI-compatibility considerations between different versions). That should also be enough time to ensure that the last c++03 release (late 2019) is really solid (for projects that still can't upgrade to c++11) and ideally there could be a few more bugfix-releases afterwards as is often done by other software projects. And before someone starts to raise straw mans: That of course wouldn't mean that a particular library *must* no longer compile in 03 mode, but one can no longer rely on the boost-internal dependencies remaining c++03 compatible. Best Mike

23 104

[ptr_container] associative container insert takes reference instead of const reference as key ?
by comic fans 30 Aug '18

30 Aug '18

Hello , I've found that ptr_unordered_map.insert has following signature (from code and latest doc) std::pair<iterator,bool> insert( key_type& k, T* x ); that forbids calls like ptr_unordered_map.insert( myobj->id(), myobj) ,I wonder if this is by design , or some other reason ? why other overload takes const key_type& k as key type? and insert always call insert_impl which have const reference as key type ? any help would be appreciated.

2 5

c++03 library survey
by Mike Dev 29 Aug '18

29 Aug '18

Hello everyone, this is closely related to the thread about "A possible date for dropping c++03 support" (https://groups.google.com/forum/#!topic/boost-developers-archive/i4UM-GfNu8w) but this is NOT meant as a vote on the suggestion, and I'd ask you to keep discussions to that thread. For the actually important part, please scroll down to the double line (===) For reference however, my suggestion was that c++03 support is officially dropped somewhere around early 2020 across all of boost. Which would mean, that from then onwards any library author could start to unconditionally use c++11 features in his library without prior announcement or transition period, even if other boost libraries that currently support c++03 have a dependency on it. (Again, if you have questions or comments about this, please answer on the other thread) Somewhat late, I realized I first should have asked if / how much actual interest there is from the side of the library maintainers in the first place, because whatever the majority of the people on the ML thinks, it obviously won't have any effect if the actually affected people don't have any interest in using c++11 in the first place. Full disclosure: I'm not a boost contributor myself (at least nothing significant) but as a user, I have an interest in boost libraries becoming simpler, less entangled with each other and providing less types that are redundant in c++11 and later. You could call that more lightweight but that is a different topic. So, to get some idea if there is any interest in this topic, I'd ask each maintainer that is currently maintaining a c++03 compatible library to answer the following questions: =======Please quote from here ====================================== - Which library/ies are you maintaining? (I assume this isn't some sort of private information - otherwise ignore the question) - Would you like to unconditionally use c++11 features if you would not have to worry about this breaking boost internal users? - Would you like to unconditionally use c++11 features if you would not have to worry about this breaking any users? - Would you deprecate your library completely if there were no boost-internal users and your current dependencies required c++11 (e.g. because your library has been merged into the c++11 standard library anyway) - Are you yourself using any boost library (in an up-to-date version) in a c++03, non-boost project? - Do you have any Idea if the latest versions of your library is used by any important/significant number of c++02 projects? [It is only important if *you* consider those projects important and or the number significant] =======Please quote till here ====================================== Note: When I'm talking about breaking users I mean breaking due to requiring c++11 compiler, not because you completely rewrite the API based on new c++11 idoms - that would probably better be done in a completely new library. Best regards and thank you for your time Mike

15 32

Re: [boost] A possible date for dropping c++03 support
by Glen Fernandes 29 Aug '18

29 Aug '18

Edward Diener wrote: > Other than not removing useful Boost libraries which support c++03 as > well as all subsequent C++ standard levels, and not telling people that > they can not use such libraries in c++03 mode if they actually want to > do so, I am perfectly willing to let others, including yourself, decide > the best way in which support for c++03 in Boost is reduced. My argument > has always been that putting a generalized statement on the website, > without explaining what it actually entails as far as using Boost l> ibraries is concerned, is going to lead to confusion and puzzlement > from end-users and endless questions. What can it possibly cost to > actually explain of what "Boost dropping support for c++03" actually > consists, when it is finally decided what Boost is going to do in this > area ? If it is a matter of correct grammar or exposition in the > explanation, I will gladly volunteer to write it if no one else wants to > do so. +1. It sounds like what we're going to communicate to users is that Boost library authors or maintainers are no longer required to make their libraries support C++03. Which sounds fine to me. I don't think library maintainers should be confined by users (even if the users are other Boost libraries) if they don't want to be. Any Boost library maintainers that wish to continue supporting their C++03 users will do so. Any other Boost library maintainers that depend on such libraries can drop the dependency on those libraries. Glen

3 3

Re: [boost] A possible date for dropping c++03 support
by Glen Fernandes 29 Aug '18

29 Aug '18

James King wrote: > I thought Peter Dimov got it right from the comment I saw earlier. > The project would no longer spend time and effort on qualifying or testing > C++03 compatibility. CI builds and the test matrix would no longer > specifically test C++03. The default language level for b2 builds would be C++11. Sounds right. All of these above is a much more useful statement to make to users. > Individual repository maintainers could attempt to continue to qualify > for C++03 however once an upstream dependency begins to include > C++11 code, that effort would have to give way. If an upstream dependency only works in C++11 and above, and the library maintainer wants to support C++03, they can either: A) Drop the dependency and still support C++03 B) Drop C++03 support But again it will be up to that library maintainer. > As a developer both working on and > consuming boost I would appreciate the permission to start using C++11 > without fear. You will be able to start using C++11 in the libraries that you maintain, without fear. You won't be able to force another library maintainer to let you use C++11 unconditionally in their library if they want to support C++03 users. Glen

1 0

BOOST_FOREACH on a filesystem directory_iterator?
by Peter Dimov 29 Aug '18

29 Aug '18

Boost.Filesystem apparently contains support for BOOST_FOREACH: https://github.com/boostorg/filesystem/blob/5a93351bfdf859ee47245e042973922… But it doesn't work: #include <boost/filesystem.hpp> #include <boost/foreach.hpp> namespace fs = boost::filesystem; int main() { fs::directory_iterator it; BOOST_FOREACH( fs::path const& p, it ) { } } 1>c:\boost-git\develop\boost/range/end.hpp(48) : error C2039: 'end' : is not a member of 'boost::filesystem::directory_iterator' The fix is trivial, but I wonder... how did nobody notice? Is this feature never used?

2 1

Future of the MaybeBoost Hash Library
by Ilia K 29 Aug '18

29 Aug '18

Hi! I was looking for a header-only library to compute SHA512 and found a very interesting project: The MaybeBoost Hash Library ( https://www.cs.mcgill.ca/~smcmur/hash/) that implements SHA/MD5 ect. In 2010 there was a discussion ( http://boost.2283326.n4.nabble.com/rfc-Preliminary-Hash-Library-td2668722.h…) about making it one of the Boost subprojects but nothing happened. Maybe some of you guys know what's the matter? -- - Ilia

2 1

Re: [boost] A possible date for dropping c++03 support
by Glen Fernandes 28 Aug '18

28 Aug '18

Peter Dimov wrote: > Edward Diener wrote: > > Peter Dimov wrote: > > > If I post "Boost is dropping support for C++03" f.ex. on Twitter or > > > Reddit, every single user will immediately understand what that means. > > > :-) > > > > I am not a participant of either so some of your humor is lost on me, but > > I can guess that it suggests that you do not consider the intelligence of > > the average Twitter or Reddit participant to be very high. > > No, that's not at all what I meant. I meant what I said. Users will > immediately understand "Boost is dropping support for C++03". I doubt hat. After the "Boost is moving to CMake" announcement on Reddit, I have a different interpretation of what Reddit will understand from "Boost <anything>". We should do things first, then announce that we've done them. Glen

2 1

1.68 Getting Started links to 1.67
by Olaf van der Spek 28 Aug '18

28 Aug '18

Hi, > The most reliable way to get a copy of Boost is to download boost_1_67_0.7z or boost_1_67_0.zip and unpack it to install a complete Boost distribution.1 1.67? Actually the best way is to use vcpkg if possible (IMO). https://www.boost.org/doc/libs/1_68_0/more/getting_started/windows.html -- Olaf

6 18

Add an adapter to cover fast bit functions
by Evgeny Shulgin 28 Aug '18

28 Aug '18

Hi all, some days ago I opened a thread about DynamicBitset[1] (where I noted that a small piece of code may double the speed of a function), which received some interesting answers (you guys rock!) I looked deeper and realized that Boost doesn't have functionality to do common bit operations *really* fast. Let me explain - there are several places in Boost where we needed to solve typical tasks connected with bits in integers - like "get log2 of an integer rounded down" or "get the number of trailing zeros" or "count number of 1-bits", and Boost contributors have been inventing there a wheel everywhere, with varying degrees of optimality: [2] - [6]. Moreover, if a programmer writes a cross-platform app and has to do smth with this stuff, it's likely that for bit operations he will write a "naive" implementations - e.g. getting the log2(x) for O(log N), when it could be done for O(log log N), but with a more complicated code. Also, as well as "smart" algos, there are other methods to use - precalced tables, taking a small additional memory when needed [6], and intrinsics (that are CPU-specific). Combining of these methods (intrinsics when conveniently, or tables/algos) gives a notable shift in performance - here's my benchmark [7] from my tiny library [8]. Performance here varies from *9.2%* to *36.9%* of speed of related naive functions. I can tell you a usercase - as a hobby I'm writing a chess variants engine (where bitsets used to represent chess board, and its size is *not* fixed to 64), and bit operations' speed there is a matter of life and death. So, what do you think of an adapter header in Boost, covering all these operation of all integer types (and maybe some other one-liners like `is_bit_set(x, pos)` ), which keeps programmers out of platform specifics? It may look as smth like this [8] (I wrote only 3 functions, but it's enough to show the potential). I guess it can be placed somewhere to *Boost.Algorithm*, and supported with CI build tests of different platforms. P.S. The (incomplete) list of bit functions, that will give a *notable* better performance compared with naive algos and even some "smart" (because of precalc/intrinsics): - count of bits - parity of bit count - first 1-bit - last 1-bit (aka integer_log2(x)) - leading zeros - trailing zeros - swap(x) - returns x with the order of the bytes reversed; for example, 0xaabb becomes 0xbbaa. (bytes here are 8 bits exactly) - rotate_left(x, shift) - rotate_right(x, shift) Other functions may look like `is_set(x, pos) -> return x & (1 << pos)` and aren't so interesting. [1]: https://lists.boost.org/Archives/boost/2018/08/242825.php [2]: https://github.com/boostorg/integer/blob/develop/include/boost/integer/inte… [3]: https://github.com/boostorg/move/blob/develop/include/boost/move/algo/detai… [4]: https://github.com/boostorg/dynamic_bitset/blob/develop/include/boost/pendi… [5]: https://github.com/boostorg/integer/blob/develop/include/boost/integer/comm… (really almost the whole file) [6]: https://github.com/boostorg/dynamic_bitset/blob/develop/include/boost/detai… [7]: https://gist.githubusercontent.com/Izaron/8c94b76818393ffd93613d255033bb48/… [8]: https://github.com/Izaron/bit_algo/blob/master/include/bits.hpp

5 6

A possible date for dropping c++03 support
by Mike Dev 28 Aug '18

28 Aug '18

> -----Original Message----- > From: Glen Fernandes <glen.fernandes(a)gmail.com> > Sent: Tuesday, August 28, 2018 1:25 AM > To: mike.dev(a)gmx.de > Subject: Re: [boost] A possible date for dropping c++03 support > > On Mon, Aug 27, 2018 at 1:10 PM Mike Dev <mike.dev(a)gmx.de> wrote: > > Conditionally using a c++11/14/17 feature is (usually) not the problem > > although there are sometimes pitfalls as Peter mentioned. However, it also > > has limited utility. E.g. it doesn't make sense to simplify a function > > implementation using c++11 features like auto, range based for, decltype, > > constexpr instead of TMP, if you have to maintain the c++03 code path as well. > > In principle, you could conditionally get rid of some boost dependencies > > in c++11 mode, but again at the cost of maintaining two different code > > paths (as boost types often have slightly different semantics from c++11). > > So why do it? And you still can't deprecate the dependency itself because > > it is still needed in c++03 mode. > > Why do it? I do it when it provides some benefit to the users: > > e.g. If alternative implementation using C++14 constexpr results in > faster compilation for users. > If supporting C++11 move semantics results in better performance > for the users. > If supporting C++11 variadic templates results in a more > flexible interface for the users. > > i.e. If I'm the maintainer, and I'm happy to have that burden of > maintenance, why does anyone else care that I support > C++03/C++11/C++14 users, in addition to C++17 users? > > Yes, these are the high value proposition cases, that you mention. > > There's also no dependency to the user is there?. e.g. If a library > obtain std::addressof from <memory> in C++11 mode and doesn't source > it from Boost.Core, to the user, the library doesn't depend on > Boost.Core. > > > So except for cases with a very high value proposition (move semantics, > > simplified api, c++11 only functionality) or simple annotations (noexcept, > > override) using c++11 features *conditionally* is usually not all that > > beneficial. My hope here is that at some point, those boost libraries > > will finally start to use c++11 features *unconditionally* in order to > > simplify things - not add even more complexity in the form of conditional > > compilation. > > Simplify things for which party? Are you worried about users or Boost > library authors/maintainers? I don't see how users are inconvenienced > unless the user wants some feature only available in later C++ modes > that the library maintainer refuses to implement. > > Glen There are (at least) three problems: 1) Not all dependencies are private. If a library e.g. uses boost::function in its interface (in particular if it returns one) the user is also directly affected by changes to that dependency. 2) As you know, the c++ compilation model is incredibly leaky, meaning transitive dependencies are not hidden from the user. E.g. if you are using boost core in your header and I include it, I do get all the symbols (including macros) in my TU too. Boost has (usually) very good hygiene, so the main problems here are usually compilation times, sometimes code size and tools (code highlighting, static analysis, refactoring etc.) that either get slower or totally break e.g. because they don't have a perfect emulation of the compilation environment and don't know which code paths are the currently active ones or are just not able to understand all the TMP. 3) Not every library in boost is as well maintained as yours and I as a user prefer "cleaner / simpler" libraries because they a) tend to have fewer bugs, b) I can more easily modify things myself if necessary, c) the easier the life of the maintainer, the more likely he has time to add new functionalities. Finally, if boost can deprecate and at some point even remove some libraries, then their maintainers (in particular the CMT) can focus their time on different projects. Btw.: In case this was not clear: I'm not a boost contributor myself and for some time now, we (as in our company) are actively trying to avoid boost dependencies for various reasons that have more to do with boost-internal stuff and the boost eco system than with e.g. inconvenient interfaces. So yes, at least some end-users do really care about the internals of boost. But admittedly, I mostly work on (semi-) embedded projects where we have to compile (and on rare occasion even modify) boost ourselves - not sure how common that is. Best Mike

3 3

[gil] Template instantiation with GCC 8 is 50x slower than with clang++
by Mateusz Loskot 26 Aug '18

26 Aug '18

Hi, One of Boost.GIL users reported very long compilation times with GCC 7 and 8 https://github.com/boostorg/gil/issues/131 then, reproduced the problem with a minimal example without Boost GIL and MPL dependencies. The issue has been reported to GCC developers - I think users/developers of other Boost libraries may be interested too https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87107 Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

1 0

[dynamic_bitset] Using of GCC built-in functions may increase performance of some methods
by Evgeny Shulgin 26 Aug '18

26 Aug '18

Hi all, when I was playing around the Boost.DynamicBitset library, I noticed the last lines of the count() function (which returns the number of bits in the bitset that are set): return do_count(m_bits.begin(), num_blocks(), Block(0), static_cast<value_to_type<(bool)mode> *>(0)); Well, this line was modified 10 years ago last time. Let's go deeper. GNU C provides several language features not found in ISO standard C. These include a bunch of bit operations - you can look at them here: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html. For example, *__builtin_popcountll *counts the number of bits in an 'unsigned long long', so we can use this kind of code to calculate bits (don't judge, I wrote this fast and didn't think of coding standards): size_type res = 0; for (size_type i = 0; i < m_bits.size(); i++) { res += __builtin_popcountll(m_bits[i]); } I checked that m_bits[] and popcount() both work with 64-bit values on my machine. It halved the running time of a program that has a bitset and calls count() over and over again - here's the code <https://gist.github.com/Izaron/5005fed4184ee6483699191dc5ef3677> I used. These __builtin_XXX functions can be used everywhere where it's possible, with preprocessor directives. Or is it actually used and longer time means something else? I used the latest version of Boost.

6 8

[test][pull#151] Fix warning: BOOST_CLANG is not defined, evaluates to 0
by Mateusz Loskot 26 Aug '18

26 Aug '18

Hi, I've submitted a tiny fix for this annoyance: https://github.com/boostorg/test/pull/151 May I ask the library maintainers to merge it? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 1

GNOME outreachy
by Pranam Lashkari 26 Aug '18

26 Aug '18

GSoC just finished and it helped grow the community by adding few new students and maybe mentors to our Boost community. I was hoping why don't we also apply for GNOME outreachy also it is also similar to GSoC and can also help our community to grow. and by appearing in end of year internship in GNOME outreachy we can keep a flow of new contributors and motivate people to contribute to opensource throughout the year. Thank you, Pranam Lashkari

14 26

[regex] Drawing attention to link issue
by Antony Polukhin 24 Aug '18

24 Aug '18

Hello, The build flags for shared libraries are changing right now in b2. See https://github.com/boostorg/boost/pull/190 for more info. The thing is that Boost.Regex fails to link with those new flags, probably because of the https://github.com/boostorg/regex/issues/49 issue. If there's no simple solution for the above case, then please merge the https://github.com/boostorg/regex/pull/66/ . It should help. Thanks in advance!

2 2

[MSM] Still maintained?
by Christophe Henry 24 Aug '18

24 Aug '18

>Hi Boost-list, > >because I realized that my simple PR for Boost.MSM [1] (which makes it >compilable with C++17) and an even older one did not receive any >attention, I wonder if Boost.MSM is still actively maintained. > >The latest changes seem to be from around December 2017. > >Does anyone know, if Christophe is still active? > > >Best regards, >Deniz Hi Deniz, Sorry, I didn't have time to do it before vacations, I only merged your change to develop now. Thanks, Christophe

2 1

[type_traits][core] modularisation and moving stuff about (again)
by John Maddock 23 Aug '18

23 Aug '18

So... I have a couple of PR's to move some of type_traits into config so it can be used by core. It's a modest proposal so I can go with that I guess... but this moving stuff about all over the place just to satisfy dependencies does wind me up a bit - I know that I sometime struggle to figure out where stuff is on Github - half of Integer is in Config for example. How on earth would an end user figure that out in order to file a PR or a bug report? I know... "calm down dear" and all that ;) So radical suggestion - does type_traits just belong in core and lets be done with it? What would happen to the file history if we moved it (can I still "git blame")? DARFC, John. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

5 16

Re: [boost] [type_traits][core] modularisation and moving stuff about (again)
by Glen Fernandes 23 Aug '18

23 Aug '18

Andrey Semashev wrote: > I would rather encourage people use type traits, the official > interface. Boost.Config or Boost.TypeTraits could provide macros that > allow users to detect whether is_final is emulated or is the real > deal. One thing about this suggestion: If Boost.Config was to provide macros that tell users whether Boost.TypeTraits' boost::is_final<T>::value is emulated or the real deal, then the compiler detection logic currently in Boost.TypeTraits for detecting __is_final would already have to be duplicated in Boost.Config. That does not sound like a great idea. Right now TypeTraits provides both, which is better. i.e. It provides boost::is_final<T>::value and BOOST_IS_FINAL(T). The former uses the latter if it is defined, or is always false if not defined. If BOOST_IS_FINAL(T) and all its compiler detection logic lives in TypeTraits, then that all that compiler detection logic should not be duplicated in Config to provide a BOOST_HAS_IS_FINAL_INTRINSIC or similar feature detection macro. Glen

5 13

[test] I want my core dumped
by Alain Miniussi 22 Aug '18

22 Aug '18

Hi, I have assert in my library code, but when the assert fire in a test, the main function in minimal.hpp intercept the signal and explains that, yes, you asked for an abort, but no: [...] ../../../boost/test/minimal.hpp(136): exception "signal: SIGABRT (application abort requested)" caught in function: 'int main(int, char **)' Is there a way to avoid that behavior ? I need that core file. Thanks Alain

3 2

[multiprecision] Design question on variable precision types.
by John Maddock 22 Aug '18

22 Aug '18

Folks, I have a tricky design question that Boost.Multiprecision has been dodging relating to variable precision types - these have just expanded somewhat now that we support complex numbers via mpc as well as mpfr's reals etc. The basic use case is this: We have a set of numbers at very high precision, some calculations are performed on those directly, others we want to temporarily drop precision, get an approximate answer and perhaps later refine it. Generally speaking, performance trumps everything, on a really long running calculation 10-20% speedup can actually make a big difference (in $$'s in some cases if the CPU time is from the cloud). Up till now Boost.Multiprecision has been dodging this issue - it's actually pretty hard to program in a sane and consistent way, so the message has been "don't mix precisions" when using a type like boost::multiprecision::mpfr_float - just set what default you want and get on with it. But we really should do better than that. So... with the help of Danielle Brake I've been trying to nail this down in develop, what we have at present is: * Copy construction or move assignment copies the precision of the source. * Regular assignment retains the precision of the target variable. This is efficient in that assignment doesn't reallocate to a new precision, and provides an easy way to up/down sample precision when required. But it breaks equality after assignment. It does match what MPC/MPFR do in mpfr_set etc though. The fact that move assignment behaves differently from regular assignment bother me too - it's too easy to write code that triggers move semantics without noticing. The trouble is, being able to assign while retaining precision of source is sometimes useful too, so having move-assign behave differently provides a useful back door, but maybe one that's just too cute for it's own good? And then.... we get on to arithmetic. * Currently temporaries are created at current default precision. So it's easy to shoot yourself in the foot by not noticing that temporaries are being created in an expression and not having the default precision set correctly. I actually think this one might be solvable, but it's a huge job involving banning default constructors in all the backends to our number types, and then catching all the cases where they might have been used. * What should happen in "a = expression", where the variable used in "expression" are at different precision to a? The uncontroversial answer might be to adjust the result to the precision of a. But hold on... we have expression templates, and these can use variable a as working space while evaluating the expression... so the change in precision might occur *during* the computation and not after it. * Should we try to ban mixed precision arithmetic altogether? It's a tempting idea, but I can't see how to enforce it in code without also banning mixed precision assignment. Thanks for your consideration, John. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

2 1

[MSM] Still maintained?
by Deniz Bahadir 22 Aug '18

22 Aug '18

Hi Boost-list, because I realized that my simple PR for Boost.MSM [1] (which makes it compilable with C++17) and an even older one did not receive any attention, I wonder if Boost.MSM is still actively maintained. The latest changes seem to be from around December 2017. Does anyone know, if Christophe is still active? Best regards, Deniz [1] https://github.com/boostorg/msm/pull/15 -- BENOCS GmbH Dipl.-Inform. Deniz Bahadir Reuchlinstr. 10 D 10553 Berlin Germany Phone: +49 - 30 / 577 0004-22 Email: deniz.bahadir(a)benocs.com www.benocs.com Advisory Board (Chairman): Oliver Fietz Board of Management: Stephan Schröder, Dr.-Ing. Oliver Holschke, Dr.-Ing. Ingmar Poese Commercial Register: Amtsgericht Bonn HRB 19378

1 0

Increasing BOOST_PP_VARIADICS_SIZE
by Damien Buhl 20 Aug '18

20 Aug '18

Dear Edward, In comparison to BOOST_PP_SEQ, BOOST_PP_VARIADICS is limited to 64 elements while BOOST_PP_SEQ is limited 255. Is there a reason for the choice of 64 or could I patch BOOST_PP_VARIADICS to go as BOOST_PP_SEQ to a limit of 255 ? Or asked differently do you think there are in newer compilers/standards a way to have an unbounded BOOST_PP_VARIADICS implementation nowadays ? Warm Regards, -- Damien Buhl Software Developer +33 6 77 43 10 05

2 2

ABI issues with -std
by Peter Dimov 20 Aug '18

20 Aug '18

At some point, we'll need to acknowledge the problem which results from building Boost with one -std and user code with another, and deal with it somehow, if just by documenting. Most of our libraries don't suffer from it at the moment but Boost.System does, because of my changes; its ABI changes between 03/11/14. So I'm going to take the initial hit. :-) POSIX platforms have long been able to ignore ABI issues so we don't mangle the library names there at all, but now whether one builds Boost for C++03, C++11 or C++14 matters, and there's nothing to prevent linking C++xx to C++yy. Even with --layout=versioned, the cxxstd level is not encoded. The fact that the default C++ standard differs between g++ and clang++ doesn't help; when following the instructions of doing "b2 install", with g++6 and above you get C++14, but with g++5 or clang++ you get C++03. The latter is very rarely what one wants today.

7 26

Formal review request: Synapse
by Emil Dotchevski 16 Aug '18

16 Aug '18

Hello, I'm requesting a formal review for Synapse, a non-intrusive signal programming library. Synapse is a non-intrusive C++ signal programming library. It is able to register connections and emit signals from any C or C++ object of any type whatsoever. If two contexts share access to a C or C++ object, they can use that object as a randezvouz point of sorts, and communicate with each other through Synapse signals. A system of meta signals provides interoperability with other signal programming libraries and callback APIs. In particular Synapse can be used to safely register C++ function objects, including lambda functions, with any C-style callback API that is designed to work only with C function pointers. In a multi-thread environment signals can be emitted asynchronously and scheduled for synchronous execution when requested in other threads. There have been numerous improvements since the first review, including the the ability to create persistent connections which don't require the user to explicitly keep them alive. See https://zajo.github.io/boost-synapse/. Thanks, Emil

2 1

Strange libstdc++ versions in travis-ci testers
by Andrzej Krzemienski 15 Aug '18

15 Aug '18

Hi Everyone, Maybe someone could help me understand the configuration on the travis-ci testers. Whenever I push a new commit I get a number of failures from travis-ci about missing std::is_trivially_default_constructible from the standard library; like here: https://travis-ci.org/boostorg/optional/builds/397519342?utm_source=email&u… Some tests with Boost.Predef indicate that they are clang compiler 3.X, and clang 5 with libstdc++ of strange version nubers: macro BOOST_LIB_STD_GNU gives values 450400026 and 460700026, which would correspond to releases 2015-04-26 and 2016-07-26, but when I look at the release notes for GCC there are no releases mentioned of these dates: https://gcc.gnu.org/news.html Maybe someone knows what versions of libstdc++ these are? Or maybe I am missing something obvious? Regards, &rzej;

5 12

numeric directory/namespace
by Robert Ramey 14 Aug '18

14 Aug '18

I'm preparing to make adjustments to safe_numerics directory and namespace in preparation to incorporating safe_numerics into the official boost distributions. I have a couple of decisions to make that someone/everyone will want to weigh in on. There is already a directory boost_root/libs/numeric which seems to be an "umbrella" for libraries dealing with numerics. It includes conversion, interval, odeint and ublas. There is an index.html in there also. But instead of referring to the above libraries, it points to the ublas documentation. So it's sort of tempting the place safe numerics in libs as a sub directory. But I really have strong reservations about the whole concept of have this "umbrella" directory in the first place. Personally I'd just prefer to use boost_root/libs/safe_numerics. I don't think the extra structure adds anything and makes it harder to implement tools which scan the directories. It would also mean that I should ? use #include <boost/numeric/safe_numeric/ ....> and I'm not sure want to do that. Also I expect I'll want to sync the namespace boost::numeric::safe_numeric:: ... with the file system. It just seems more complex and flexible than it has to be. I see the future of boost as diminishing coupling between libraries and I see the current setup as not helping with this. Please don't wait to answer until I've made the changes. Robert Ramey

3 2

[container] [flat_map] Error with heterogeneous comparator and std::string_view
by Viktor Sehr 13 Aug '18

13 Aug '18

On MSVC (latest) the following code yields a compile error with flat_map, but not with std::map. I do not have the knowledge of std::less<> to resolve what causes the error. auto fm = boost::container::flat_map<std::string, int, std::less<> >{}; auto m = std::map<std::string, int, std::less<> >{}; auto k = std::string_view{ "my_key" }; auto x = m.find(k); // Compiles auto y = fm.find(k); // Does NOT compile Error message: 1>boost\container\flat_map.hpp(1314): error C2664: 'boost::container::vec_iterator<boost::container::dtl::pair<Key,T> *,true> boost::container::dtl::flat_tree<boost::container::dtl::pair<Key,T>,boost::container::dtl::select1st<Key>,Compare,boost::container::new_allocator<T2>>::find(const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &) const': cannot convert argument 1 from 'const std::string_view' to 'const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &' 1> with 1> [ 1> Key=std::string, 1> T=int, 1> Compare=std::less<void>, 1> T2=boost::container::dtl::pair<std::string,int> 1> ] 1> boost\container\flat_map.hpp(1314): note: Reason: cannot convert from 'const std::string_view' to 'const std::basic_string<char,std::char_traits<char>,std::allocator<char>>' 1> boost\container\flat_map.hpp(1314): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called Best regards /Viktor

4 7

Library Federation
by Robert Ramey 12 Aug '18

12 Aug '18

I'm now taking steps to get safe numerics integrated into the boost distribution. It's reminded me of a running complaint I have about using boost. a) When I use anything boost, I'm required to do two things: i) run b2 headers to create a forwarding header in the boost directory ii) include via command line or INCLUDE variable to boost root. b) If I want to use safe_numerics before it is included in the boost distribution, I have to place safe_numerics into it's expected destination in the boost hierarchy and run b2 headers AGAIN to make things match up. This is even more problematic in that b2 headers is not invoked "automagically" in such a way that people don't know it's there. To me, this just makes it harder to use / test any new library with boost without dragging in access to a bunch of stuff I may not want. It inhibits those without beam foo from running the tests etc. This is why I did things the way I did. Now I'm getting ready to add it to the boost distribution, I'll change this to do it the "boost way". Not so much because I think it's better but in this case, consistency is better than variety. But I'm still unsatisfied with the situation. It's part of the reason that boost is avoided when possible by many people. Isn't there a better way? I think there might be. Rather than sprinkling a bunch of forwarding headers around my file system - which are "sticky" and need to be updated from time to time, how about depending on the "INCLUDE" environmental variables available in gcc and msvc and clang. Using "some method", I would be able generate this variable via some sort of batch script - not too tough. And work as I do now. But a) the script would be re-run when ever I changed projects so that it "stuck" in my file system. b) It could be smarter - include only the boost include directories I'm actually using - thus avoiding accidently including surprising stuff. c) We have tools which figure out boost dependencies automatically so I don't think it would be a big stretch to do this automagically. d) If my project is "larger" and includes a bunch of stuff from other libraries, I could add these in as well. This would give my the concept of "library federation" where my app is linked to some list defined as part of the project. I'm sure this concept also sort of exists. e) my pet request would be that I could say: tool application.cpp ... >include environment output to generate the env output for all the target apps. Of course one could you * wild cards as well. This would let me create one set on includes for building/running my test suite and a different one for examples and a different one for my "real" application. I'll stop there so as to leave opportunity for discussion. Robert Ramey

3 7

Please merge into boostorg superproject
by James E. King III 11 Aug '18

11 Aug '18

Please merge into boost superproject - these have passed CI and have been reviewed: https://github.com/boostorg/boost/pull/186 https://github.com/boostorg/boost/pull/181 Please decide what to do with: https://github.com/boostorg/boost/pull/39 (I can't tell if this is defunct?) https://github.com/boostorg/boost/pull/184 (do we want this in the superproject, or a submodule called boostorg/docker, or not at all?) Thanks, Jim

1 0

iostreams in 1.68.0
by James E. King III 11 Aug '18

11 Aug '18

Hi folks, just a note that none of the changes since 1.67.0 got into 1.68.0 master. They were on develop and never merged. I just merged them for 1.69.0. - Jim

1 0

[release] 1.69.0 open for merging
by Marshall Clow 10 Aug '18

10 Aug '18

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

2 1

[release] Boost 1.68.0
by Marshall Clow 09 Aug '18

09 Aug '18

Release 1.68.0 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 1 new libraryand numerous enhancements and bug fixes for existing libraries. For details, including download links, see <https://www.boost.org/users/news/version_1.68.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.68.0/> To install this release on your system, see <https://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team

5 5

Re: [boost] [Boost-users] [release] Boost 1.68.0 Beta 1 -> warnings in gil, locale, geometry, asio, ublas, interprocess, atomic
by Frédéric 09 Aug '18

09 Aug '18

Here are some more warnings while using the libraries: * gil: boost/gil/extension/toolbox/image_types/indexed_image.hpp:190:5: warning: les qualificatifs de type sont ignorés sur le type retourné par la fonction [-Wignored-qualifiers] const std::size_t num_colors() const { return _num_colors; } ^~~~~ boost/gil/extension/dynamic_image/any_image_view.hpp:41:63: warning: unused parameter 'v' [-Wunused-parameter] template <typename T> result_type operator()(const T& v) const { return num_channels<T>::value; } boost/gil/extension/dynamic_image/algorithm.hpp:147:70: warning: unused parameter 'src' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} ^ boost/gil/extension/dynamic_image/algorithm.hpp:147:88: warning: unused parameter 'val' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} ^ boost/gil/extension/dynamic_image/image_view_factory.hpp:178:140: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ boost/gil/extension/dynamic_image/image_view_factory.hpp:201:144: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type any_color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ boost/gil/io/device.hpp:446:31: warning: unused parameter 'data' [-Wunused-parameter] void write( const byte_t* data ^ boost/gil/io/device.hpp:447:31: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ boost/gil/io/device.hpp:471:35: warning: unused parameter 'data' [-Wunused-parameter] std::size_t read( byte_t* data ^ boost/gil/io/device.hpp:472:35: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ * locale: boost/locale/utf.hpp:224:17: warning: cette instruction peut poursuivre son chemin [-Wimplicit-fallthrough=] c = (c << 6) | ( tmp & 0x3F); ^ boost/locale/utf.hpp:225:13: note: ici case 2: ^~~~ boost/locale/utf.hpp:231:17: warning: cette instruction peut poursuivre son chemin [-Wimplicit-fallthrough=] c = (c << 6) | ( tmp & 0x3F); ^ boost/locale/utf.hpp:232:13: note: ici case 1: ^~~~ * geometry: boost/geometry/formulas/vertex_longitude.hpp:340:32: warning: unused parameter 'lon1' [-Wunused-parameter] static inline CT apply(CT& lon1, ^ boost/geometry/formulas/vertex_longitude.hpp:341:32: warning: unused parameter 'lat1' [-Wunused-parameter] CT& lat1, ^ boost/geometry/formulas/vertex_longitude.hpp:343:32: warning: unused parameter 'lat2' [-Wunused-parameter] CT& lat2, ^ boost/geometry/formulas/vertex_longitude.hpp:344:38: warning: unused parameter 'vertex_lat' [-Wunused-parameter] CT const& vertex_lat, ^ boost/geometry/formulas/vertex_longitude.hpp:345:32: warning: unused parameter 'alp1' [-Wunused-parameter] CT& alp1, ^ boost/geometry/formulas/vertex_longitude.hpp:346:44: warning: unused parameter 'azimuth_strategy' [-Wunused-parameter] Strategy const& azimuth_strategy) ^ boost/geometry/strategies/spherical/intersection.hpp:544:81: warning: unused parameter 'b2' [-Wunused-parameter] Point2 const& b1, Point2 const& b2, // in ^ boost/geometry/algorithms/detail/envelope/segment.hpp:156:61: warning: unused parameter 'lon1' [-Wunused-parameter] static inline void compute_box_corners(CalculationType& lon1, ^ boost/geometry/algorithms/detail/envelope/segment.hpp:158:61: warning: unused parameter 'lon2' [-Wunused-parameter] CalculationType& lon2, ^ boost/geometry/strategies/spherical/intersection.hpp:544:81: warning: unused parameter 'b2' [-Wunused-parameter] Point2 const& b1, Point2 const& b2, // in ^ * asio (windows 32 and 64 bits with mingw w64 + g++ 8.2.0) : /softs/win32-mingw-8.2.0/release/boost/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp: Dans la fonction membre « boost::system::error_code boost::asio::detail::win_iocp_socket_service_base::cancel(boost::asio::> /softs/win32-mingw-8.2.0/release/boost/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:253:51: warning: transtypage entre types de fonctions incompatibles de « FARPROC » {aka « int (__attribute__((stdcall)) *)()> cancel_io_ex_t cancel_io_ex = (cancel_io_ex_t)cancel_io_ex_ptr; ^~~~~~~~~~~~~~~~ * ublas: /softs/lin64-gcc-8.2.0/debug/boost/include/boost/numeric/ublas/matrix_expression.hpp:2224:17: warning: cette instruction « if » ne protège pas… [-Wmisleading-indentation] if (it2_ != it2_end_) ^~ /softs/lin64-gcc-8.2.0/debug/boost/include/boost/numeric/ublas/matrix_expression.hpp:2227:21: note: …cette instruction, mais l'indentation de cette dernière est trompeuse car elle fait croire qu'elle est gardée par le « if » if (it2_ != it2_end_) { ^~ boost/numeric/ublas/functional.hpp:1673:57: warning: unused parameter 'size_i' [-Wunused-parameter] size_type upper_element (size_type i, size_type size_i, size_type j, size_type size_j) { ^ boost/numeric/ublas/functional.hpp:1673:88: warning: unused parameter 'size_j' [-Wunused-parameter] size_type upper_element (size_type i, size_type size_i, size_type j, size_type size_j) { ^ * interprocess (windows mingw-w64 + g++ 8.2.0 32/64 bits): In file included from boost/interprocess/errors.hpp:41, from boost/interprocess/exceptions.hpp:24, from boost/interprocess/sync/file_lock.hpp:24, from Progs/delypse-transfer.cpp:32: boost/interprocess/detail/win32_api.hpp:189:8: warning: « struct boost::interprocess::winapi::IUnknown_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IUnknown_BIPC ^~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:200:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemClassObject_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:200:8: warning: « struct boost::interprocess::winapi::IWbemClassObject_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:306:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemContext_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:306:8: warning: « struct boost::interprocess::winapi::IWbemContext_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:345:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IEnumWbemClassObject_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:345:8: warning: « struct boost::interprocess::winapi::IEnumWbemClassObject_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:369:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemServices_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:369:8: warning: « struct boost::interprocess::winapi::IWbemServices_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:518:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemLocator_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:518:8: warning: « struct boost::interprocess::winapi::IWbemLocator_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] In file included from boost/interprocess/errors.hpp:41, from boost/interprocess/exceptions.hpp:24, from boost/interprocess/sync/file_lock.hpp:24, from Progs/delypse-transfer.cpp:32: boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_system_time_of_day_information(boost::interprocess::winapi::system_timeofday_information&) »: boost/interprocess/detail/win32_api.hpp:1676:58: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::NtQuerySystemInformation); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::unlink_file(const char*) »: boost/interprocess/detail/win32_api.hpp:1892:78: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (NtSetInformationFile_t)dll_func::get(dll_func::NtSetInformationFile); ^ boost/interprocess/detail/win32_api.hpp:1894:94: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtQueryObject_t pNtQueryObject = (NtQueryObject_t)dll_func::get(dll_func::NtQueryObject); ^ boost/interprocess/detail/win32_api.hpp:1966:85: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtOpenFile_t pNtOpenFile = (NtOpenFile_t)dll_func::get(dll_func::NtOpenFile); ^ boost/interprocess/detail/win32_api.hpp:1967:73: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtClose_t pNtClose = (NtClose_t)dll_func::get(dll_func::NtClose); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_file_mapping_size(void*, long long int&) »: boost/interprocess/detail/win32_api.hpp:2413:63: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (NtQuerySection_t)dll_func::get(dll_func::NtQuerySection); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_semaphore_info(void*, long int&, long int&) »: boost/interprocess/detail/win32_api.hpp:2426:86: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (winapi::NtQuerySemaphore_t)dll_func::get(winapi::dll_func::NtQuerySemaphore); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_timer_resolution(long unsigned int*, long unsigned int*, long unsigned int*) »: boost/interprocess/detail/win32_api.hpp:2437:98: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (winapi::NtQueryTimerResolution_t)dll_func::get(winapi::dll_func::NtQueryTimerResolution); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_performance_counter(long long int*) »: boost/interprocess/detail/win32_api.hpp:2444:57: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::QueryPerformanceCounter); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_performance_frequency(long long int*) »: boost/interprocess/detail/win32_api.hpp:2451:59: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::QueryPerformanceFrequency); ^ * atomic (OSX): boost/include/boost/atomic/detail/ops_gcc_x86_dcas.hpp:269:113: warning: unused parameter 'order' [-Wunused-parameter] static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT

4 6

Note: the Master branch is not yet open for merging
by Marshall Clow 09 Aug '18

09 Aug '18

Even though we have a release, I've got some tagging to do, etc. The master branch will be open tomorrow. -- Marshall

1 0

[release] Boost 1.68.0 Release Candidate 1
by Marshall Clow 05 Aug '18

05 Aug '18

The release candidates for the 1.68.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.68.0/source/> The SHA256 checksums are as follows: 59804d8fad02cf3b09485f3dbc0f9097c05fc1e0123f0c133b35a6c6f601109a boost_1_68_0_rc1.7z 7f6130bc3cf65f56a618888ce9d5ea704fa10b462be126ad053e80e553d6d8b7 boost_1_68_0_rc1.tar.bz2 da3411ea45622579d419bfda66f45cd0f8c32a181d84adfa936f5688388995cf boost_1_68_0_rc1.tar.gz 3b1db0b67079266c40b98329d85916e910bbadfc3db3e860c049056788d4d5cd boost_1_68_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. The web site will be updated today as well.

6 8

[release] Boost 1.68.0 Beta 1
by Marshall Clow 02 Aug '18

02 Aug '18

Boost release 1.67.0 beta 1 is now available at: https://dl.bintray.com/boostorg/beta/1.68.0.beta1/source/ The files are identical to the RC2 that was posted on Friday. The SHA256 checksums are as follows: 961d2bdc74c1499c931b32098842abba8883b1a89ef5c8f8f0ab0aff771a3ce5 boost_1_68_0_b1_rc2.7z 0364846258648e39908ca7cebfc2d2216eef6980c32aaf8276d2cfe73ef012e3 boost_1_68_0_b1_rc2.tar.bz2 d99105685a68907a76b0479ecde77915423246236ef0db9cb846c5bfc09b41f3 boost_1_68_0_b1_rc2.tar.gz 6158e0e961bfb0d8adeb2ea70337b08504668258025f0a873fb21eee3436d22e boost_1_68_0_b1_rc2.zip For details of what's in the release, see <http://www.boost.org/users/history/version_1_68_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

3 7

Moving wiki/Guidelines/WarningsGuidelines
by Mateusz Loskot 02 Aug '18

02 Aug '18

Hi, Paul Bristow suggested [1] "We might also re-host this document somewhere on github/boostorg?" [1] https://lists.boost.org/Archives/boost/2018/07/242617.php I'd like to edit and move the wiki page away from Trac. IMHO, it is reasonable to host it not on GitHub wiki but on boost.org along other guidelines, for example, at https://www.boost.org/development/warnings.html - It is easy to update website via pull requests. - Any updates would be a subject of some review at least Thoughts? Objections? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

3 7

[release] 1.68.0 closed for release
by Marshall Clow 02 Aug '18

02 Aug '18

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 tomorrow. Thanks, -- The Boost Release Team

1 0

[release] 1.68.0 post-beta merges
by Marshall Clow 01 Aug '18

01 Aug '18

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> The master branch will close for the 1.68.0 release on August 1st. -- Marshall

11 34

[filesystem] PR backlog needs attention
by James E. King III 01 Aug '18

01 Aug '18

There are 29 open PRs going back 3 years. This backlog needs some attention. Some of the pull requests (like documentation changes to fix typos) are trivial. I ran into a warning while building another library that I found was already submitted as a fix in the PRs, but has missed the 1.68.0 release now. Thanks, Jim

4 5

Re: [boost] [Boost-users] [release] Boost 1.68.0 Beta 1 -> warnings in filesystem, locale, thread, stacktrace, container
by Frédéric 30 Jul '18

30 Jul '18

Hi, I have tested 1.68.0 on linux x86_64 with the following compilers: - g++ 8.2.0, - clang++ 5.0.2, - mingw-w64 + g++ 8.2.0 cross compiling to windows 32 bits, - mingw-w64 + g++ 8.2.0 cross compiling to windows 64 bits, - clang++ 5.0.2 cross compiliing to OSX 10.9 32 bits, - clang++ 5.0.2 cross compiliing to OSX 10.9 64 bits. I did not find any major issue. Just those warnings while building the libraries: * filesystem (g++ 8.2.0 and clang++ 5.0.2 on linux x86_64): libs/filesystem/src/operations.cpp: Dans la fonction « int {anonymous}::readdir_r_simulator(DIR*, dirent*, dirent**) »: libs/filesystem/src/operations.cpp:2126:18: warning: « int readdir_r(DIR*, dirent*, dirent**) » est obsolète [-Wdeprecated-declarations] { return ::readdir_r(dirp, entry, result); } ^~~~~~~~~ In file included from /usr/include/features.h:423, from /softs/gcc-8.2.0/include/c++/8.2.0/x86_64-pc-linux-gnu/bits/os_defines.h:39, from /softs/gcc-8.2.0/include/c++/8.2.0/x86_64-pc-linux-gnu/bits/c++config.h:508, from /softs/gcc-8.2.0/include/c++/8.2.0/cstddef:49, from ./boost/config/compiler/gcc.hpp:165, from ./boost/config.hpp:39, from ./boost/filesystem/operations.hpp:18, from libs/filesystem/src/operations.cpp:68: /usr/include/dirent.h:189:12: note: déclaré ici extern int __REDIRECT (readdir_r, ^~~~~~~~~~ * locale (many more than that one about deprecated std::auto_ptr): I wonder when auto_ptr will be removed but it would be nice to change it to unique_ptr. In file included from libs/locale/src/util/default_locale.cpp:10: ./boost/locale/util.hpp:180:28: warning: « template<class> class std::auto_ptr » est obsolète [-Wdeprecated-declarations] BOOST_LOCALE_DECL std::auto_ptr<base_converter> create_utf8_converter(); ^~~~~~~~ In file included from /softs/gcc-8.2.0/include/c++/8.2.0/bits/locale_conv.h:41, from /softs/gcc-8.2.0/include/c++/8.2.0/locale:43, from ./boost/locale/util.hpp:10, from libs/locale/src/util/default_locale.cpp:10: /softs/gcc-8.2.0/include/c++/8.2.0/bits/unique_ptr.h:53:28: note: déclaré ici template<typename> class auto_ptr; ^~~~~~~~ * thead with mingw w64 cross compiling to windows 32 bits on linux x86_64 with g++ 8.2.0: I guess this warning is due to the fact that time_t is 32 bits on windows 32 bits so this looks dangerous to me. libs/thread/src/win32/thread_primitives.cpp: Dans la fonction « boost::detail::win32::ticks_type boost::detail::win32::{anonymous}::get_tick_count_init() »: libs/thread/src/win32/thread_primitives.cpp:97:120: warning: transtypage entre types de fonctions incompatibles de « boost::winapi::FARPROC_ » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::detail::win32::detail::gettickcount64_t » {aka « long long unsigned int (__attribute__((stdcall)) *)() »} [-Wcast-function-type] (boost::detail::win32::detail::gettickcount64_t)boost::winapi::get_proc_address(hKernel32, "GetTickCount64"); * stacktrace (windows 32 and 64 bits): In file included from ./boost/winapi/file_management.hpp:17, from ./boost/stacktrace/detail/safe_dump_win.ipp:20, from ./boost/stacktrace/safe_dump_to.hpp:210, from ./boost/stacktrace/frame.hpp:20, from ./boost/stacktrace/detail/frame_unwind.ipp:15, from libs/stacktrace/build/../src/basic.cpp:14: ./boost/winapi/overlapped.hpp:38:9: warning: le C++ ISO interdit les structures anonymes [-Wpedantic] }; ^ * iostreams (windows 64 bits): libs/iostreams/src/mapped_file.cpp: Dans la fonction membre « void boost::iostreams::detail::mapped_file_impl::try_map_file(boost::iostreams::detail::mapped_file_impl::param_type) »: libs/iostreams/src/mapped_file.cpp:324:29: warning: comparaison d'expressions entières de types signés différents: « boost::iostreams::stream_offset » {aka « long long int »} et « boost::iostreams::mapped_file_source::size_type » {aka « long long unsigned int »} [-Wsign-compare] (SIZE_T) (size_ != max_length ? size_ : 0), ~~~~~~^~~~~~~~~~~~~ gcc.compile.c++ bin.v2/libs/iostreams/build/gcc-8.2.0/debug/link-static/target-os-windows/threading-multi/gzip.o * container (OSX 32 and 64 bits, clang 5.0.2): many locations with this warning: In file included from libs/container/src/alloc_lib.c:24: In file included from libs/container/src/dlmalloc_ext_2_8_6.c:36: libs/container/src/dlmalloc_2_8_6.c:4085:27: warning: 'sbrk' is deprecated [-Wdeprecated-declarations] char* base = (char*)CALL_MORECORE(0); ^ libs/container/src/dlmalloc_2_8_6.c:1714:37: note: expanded from macro 'CALL_MORECORE' #define CALL_MORECORE(S) MORECORE_DEFAULT(S) ^ libs/container/src/dlmalloc_2_8_6.c:666:26: note: expanded from macro 'MORECORE_DEFAULT' #define MORECORE_DEFAULT sbrk ^ /softs/osxcross-10.9-5.0.2/bin/../SDK/MacOSX10.9.sdk/usr/include/unistd.h:580:1: note: 'sbrk' has been explicitly marked deprecated here __deprecated ^ /softs/osxcross-10.9-5.0.2/bin/../SDK/MacOSX10.9.sdk/usr/include/sys/cdefs.h:156:37: note: expanded from macro '__deprecated' #define __deprecated __attribute__((deprecated)) ^

2 2

Release notes piling up
by James E. King III 30 Jul '18

30 Jul '18

There are 12 PRs for updating the documentation (they are going to have merge conflicts)... who is managing that for this release cycle? https://github.com/boostorg/website/pulls - Jim

5 8

TROJAN INFECTION boost 1.67 binaries for Windows x64 MSVC 14.1
by Zipper Fish 28 Jul '18

28 Jul '18

Dear boost developers and/or release managers: Today I downloaded boost_1_67_0-msvc-14.1-64.exe from the Windows binaries downloads page: https://dl.bintray.com/boostorg/release/1.67.0/binaries/ The file contains a Trojan, according to Windows Defender. Screenshot: https://usercontent.irccloud-cdn.com/file/Uy6o19AC/2018-07-26%2016_29_52-Wi… Someone should verify this & check the other pre-built binaries ASAP to reduce exposure. Thank you & best regards

6 11

Design question SafeFloat
by Damian Vicino 28 Jul '18

28 Jul '18

Hi, I'm working in simplifying safe_float to prepare it for future review. For now I'm focusing in a C++17 compatible version. Currently safefloat receives 2 template parameters: template<typename FP, typename P> class safe_float ... Where FP is the floating point value being made "safe", float, double, long double ... and P is a Policy of what to check and how to react. The how to react is a class that I pass by template parameter to the Policy. So, policy looks like: template<typename R> class policy_x .... I had a very complicated way of producing those policies, I used many TMP tricks so the logic stays in the policy and combines, but now that if-constexpr is available it may not make sense to take that path anymore. And, I see it may be better to simplify as much as possible. So, I'm thiking in make policy like a "config" description and put if constexprs in the safe_float class to decide what to do based in that. I want a bad policy to fail execution. I'm wondering what is the best approach for defining that "config-like" policy. A policy check is a bidimensional matrix of the operation affected and the flags considered (FE_ENV flags). For example, I want a policy to tell something like "check overflow in additions and underflow in division". These are the options I'm considering 1) define typenames for each flag and assign them tuple of affected operations class addition; class division; class multiplication; class subtraction; template<typename R> struct policy_x { using reporter=R; using overflow=tuple<addition>; using underflow=tuple<division>; using invalid=tuple<>; using inexact=tuple<>; }; 2) define typename by operation, passing class with constexprs of flags being evaluated struct empty_check{ static constexpr bool check_overflow=false; static constexpr bool check_underflow=false; static constexpr bool check_invalid=false; static constexpr bool check_inexact=false; }; struct check_overflow : public empty_check { static constexpr bool check_overflow=true; }; struct check_underflow : public empty_check { static constexpr bool check_underflow=true; }; template<typename R> struct policy_x { using reporter=R; using addition=check_overflow; using subtraction=empty_check; using multiplication=empty_check; using division=check_underflow; }; 3) similar to 2, but using true_type, and false_type in place of constexpr variables. struct empty_check{ using check_overflow=false_type; using check_underflow=false_type; using check_invalid=false_type; using check_inexact=false_type; }; struct check_overflow : public empty_check { using check_overflow=true_type; }; struct check_underflow : public empty_check { using check_underflow=true_type; }; template<typename R> struct policy_x { using reporter=R; using addition=check_overflow; using subtraction=empty_check; using multiplication=empty_check; using division=check_underflow; 4) other options? Thanks for any comments in advance. Damian

3 4

Promise/A+ like javascript in cpp
by hawk x 27 Jul '18

27 Jul '18

Hi, Javascript Promise creates a task chain to help develop asynchronized application with single thread. I did not find a good implement of this kind of "Promise" in c++, so i create one named "promise-cpp" here -- https://github.com/xhawk18/promise-cpp with which, we can write asynchronized tasks like sequential flows. Here's an example of promisifed http client in boost::asio -- https://github.com/xhawk18/promise-cpp/blob/master/test/asio_http_client.cpp "promise-cpp" would be the best friend to boost::asio's asynchronized task for single thread, and it is not std::promise. Thanks for you reviewing this library and any suggestion will be appreciated!

3 4

Docker environment(s) for Boost Development
by James E. King, III 26 Jul '18

26 Jul '18

I submitted a pull request into the superproject containing some docker scripts. The intention of this is to simplify managing a docker build environment for boost: https://github.com/boostorg/boost/pull/184 I'm wondering if folks will find this useful, and whether folks think this should be in its own submodule instead of being in boostorg/boost. I only have an Ubuntu Bionic environment in this pull request but it wouldn't be that difficult to add debian, centos, and others, as well as various versions of each. I have tested it on Unix and on Windows. On Unix the performance is quite good overall - but on Windows since they use SMB to do the sharing it is really slow (I would say a good 20 times slower between typing "b2" and getting the first output as it scans through all the files. I would recommend continuing to use a virtual machine on Windows Hosts for unix boost development, but this option is there and hopefully they will improve things. This partially came out of the discussion we had a number of months back about how we handle third party dependencies. For the most part one has to look at README files in various locations to learn about them. This is an attempt to pull all the dependencies together for a complete build into one place (the Dockerfile). One day when Microsoft supports Visual Studio compilation inside a reasonably sized windows container (i.e. based on nanoserver and not Windows Server Core), I'd like to add that as well since managing the dependencies on Windows is a bit harder (you usually have to build them). Thanks, Jim

5 8

boost include directory question
by Robert Ramey 21 Jul '18

21 Jul '18

The current instructions for doing boost development are approximately: a) clone the boost super project from github. b) invoke b2 headers which does one of: 1) creates links in the boost root directory to individual projects 2) or copies boost directories from individual libraries into the boost root directory. depending on whether it is a windows system or other system. Since I test for both windows and other systems, this is somewhat of a pain. In considering my options, I'm wondering if specifying all the boost library include directories in the CPLUS_INCLUDE_PATH environmental variable (gcc compilers) or INCLUDE (msvc). a) Has this been considered before? b) Was it considered when the current system was setup? c) Is there an reason why it wouldn't be a good idea? Anyone with information on this is free to chime in. Actually anyone is free to chime in. Robert Ramey

3 4

[concept_check] stl_concept_covering - compiler, stdlib, boost, or test issue?
by James E. King III 20 Jul '18

20 Jul '18

Hi folks, The test stl_concept_covering is annotated with "gcc bug" on a number of tests, and yet gcc 7.3.0 (with libstdc++) and clang-6.0 (with libc++ or libstdc++) fail to compile this test, mostly on the sections marked as a bug. For example: "/usr/bin/clang++-6.0" -c -x c++ -stdlib=libc++ -fPIC -m64 -O0 -fno-inline -Wall -g -DBOOST_ALL_NO_LIB=1 -I"../.." -o "../../bin.v2/libs/concept_check/test/ stl_concept_covering.test/clang-linux-6.0/debug/stl_concept_covering.o" "test/stl_concept_covering.cpp" In file included from test/stl_concept_covering.cpp:9: /usr/local/include/c++/v1/algorithm:999:24: error: invalid operands to binary expression ('boost::input_iterator_archetype<boost::equality_comparable2_first_ar chetype<boost::null_archetype<int> >, 0>::reference' and 'const boost::equality_comparable2_second_archetype<boost::null_archetype<int> >') if (*__first == __value_) ~~~~~~~~~~ ^ ~~~~~~~~ test/stl_concept_covering.cpp:152:15: note: in instantiation of function template specialization 'std::__1::find<boost::input_iterator_archetype<boost::equalit y_comparable2_first_archetype<boost::null_archetype<int> >, 0>, boost::equality_comparable2_second_archetype<boost::null_archetype<int> > >' requested here in = std::find(in, in, value); Full log with gcc-7.3.0 here: https://travis-ci.org/boostorg/concept_check/jobs/404203085#L1517 What's interesting is that if I change the type of in to an input_iterator_archetype_no_proxy the test passes. When I look at the concept_archetypes I see that input_iterator_archetype is a template with a default parameter, but also defines "reference" as a structure with an operator(), instead of using a typedef which is what I usually see done. So this makes me wonder if it's really a compiler issue (both compilers and std C++ libs complain the same way though) or if the archetype is invalid. I'm not sure the best course of action. It does cause most CI build jobs to fail, except MSVC jobs interestingly enough. Any thoughts you could share on this would be appreciated. The PR with all the build jobs showing errors can be found here: https://github.com/boostorg/concept_check/pull/13 Thanks, Jim

3 4

[range] [concepts] Boost 1.68 beta build error in RandomAccessIteratorConcept using latest MSVC
by Viktor Sehr 20 Jul '18

20 Jul '18

The following error is emitted in latest MSVC building Boost 1.68 beta: 1>\boost\range\concepts.hpp(257): error C3646: 'n': unknown override specifier 1>\boost\range\concepts.hpp(264): note: see reference to class template instantiation 'boost::range_detail::RandomAccessIteratorConcept<Iterator>' being compiled 1>\range\concepts.hpp(257): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int Unfortunately I'm not competent enough to determine what is causing the error: Full struct: template<class Iterator> struct RandomAccessIteratorConcept : BidirectionalIteratorConcept<Iterator> { #if BOOST_RANGE_ENABLE_CONCEPT_ASSERT BOOST_RANGE_CONCEPT_ASSERT(( Convertible< BOOST_DEDUCED_TYPENAME RandomAccessIteratorConcept::traversal_category, random_access_traversal_tag >)); BOOST_CONCEPT_USAGE(RandomAccessIteratorConcept) { i += n; i = i + n; i = n + i; i -= n; i = i - n; n = i - j; } private: // MSVC 14.1 - avoid C4596: 'difference_type': illegal qualified name in member declaration #if defined(_MSC_VER) && _MSC_VER >= 1912 BOOST_DEDUCED_TYPENAME difference_type n; #else BOOST_DEDUCED_TYPENAME RandomAccessIteratorConcept::difference_type n; #endif Iterator i; Iterator j; #endif }; br/Viktor Sehr

3 3

[system] Clang CI builds broken because of constexpr
by Andrey Semashev 20 Jul '18

20 Jul '18

Hi, I'm seeing these errors in Travis CI builds with Clang 3.8, 3.9, 4.0 and 5.0: ./boost/system/error_code.hpp:232:41: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr] BOOST_SYSTEM_CONSTEXPR explicit std_category( boost::system::error_category const * pc ): pc_( pc ) ^ ./boost/system/error_code.hpp:232:41: note: non-constexpr constructor 'error_category' cannot be used in a constant expression /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/system_error:69:5: note: declared here error_category() noexcept; ^ I'm assuming this is because the compiler uses libstdc++ from gcc 4.8, in which error_category() is not marked constexpr. Can this be fixed somehow?

2 2

Looking for help on preparing for review
by Damian Vicino 20 Jul '18

20 Jul '18

Hi, I'm preparing my library safe_float to be proposed for review. The library was born in the GSOC2015, but it never reached a review ready state. My plan is to change that in the next few months. At this point, I'm looking for some volunteers to proof-read the documentation. Code is going through major rewrite, and I will send another mail looking for help with reviewing the code when that is done. The most current documentation can be read directly from the web here: https://sdavtaker.github.io/safefloat/ Any comment is appreciated. Best regards, Damian

5 9

[Compute] Conflict between boost::compute::zip_iterator and boost::iterators::zip_iterator
by fortenberry.rm＠protonmail.com 18 Jul '18

18 Jul '18

I'd like to use boost::compute and boost::range together, like below, but if I uncomment the '#include <boost/range/combine.hpp>' line I get an error saying that boost::compute::zip_iterator and boost::iterators::zip_iterator are ambiguous. Is there a way around this, so that I can use boost::compute and boost::range together in the same cpp file? I am using on Windows vs2015 64bit. Boost 1.67.0. Code: #include <vector> #include <iostream> #include <algorithm> //#include <boost/range/combine.hpp> #include <boost/compute/lambda.hpp> #include <boost/compute/functional/math.hpp> #include <boost/compute/container/vector.hpp> #include <boost/compute/algorithm/transform.hpp> namespace compute = boost::compute; using compute::float4_; using compute::lambda::_1; using compute::lambda::_2; using compute::lambda::distance; int main() { // get default device and setup context compute::device device = compute::system::default_device(); compute::context context(device); compute::command_queue queue(context, device); // generate random data on the host std::vector<float4_> a(10000); std::vector<float4_> b(10000); std::vector<float> r(10000); std::generate((float*)a.data(), (float*)(a.data() + a.size()), rand); std::generate((float*)b.data(), (float*)(b.data() + b.size()), rand); // create a vector on the device compute::vector<float4_> _a(a.size(), context); compute::vector<float4_> _b(b.size(), context); compute::vector<float> _r(r.size(), context); // transfer data from the host to the device compute::copy(a.begin(), a.end(), _a.begin(), queue); compute::copy(b.begin(), b.end(), _b.begin(), queue); boost::compute::transform( _a.begin(), _a.end(), _b.begin(), _r.begin(), distance(_1, _2), queue ); // copy values back to the host compute::copy(_r.begin(), _r.end(), r.begin(), queue); for (int i = 0; i < a.size(); ++i) { float4_ va = a[i]; float4_ vb = b[i]; float vr = r[i]; float e = std::sqrt(std::pow(va[0] - vb[0], 2) + std::pow(va[1] - vb[1], 2) + std::pow(va[2] - vb[2], 2) + std::pow(va[3] - vb[3], 2)); std::cout << std::setprecision(12); if (std::abs(e - vr) > 1e-2) std::cout << e << " != " << vr << "\n"; } return 0; } Error, truncated for brevity. I can post the full error log if it is helpful: 1>------ Build started: Project: demo, Configuration: Debug x64 ------ 1> demo.cpp 1> This header is implementation detail and provided for backwards compatibility. 1>C:\local\boost_1_67_0\boost/compute/algorithm/transform.hpp(67): error C2668: 'boost::compute::make_zip_iterator': ambiguous call to overloaded function 1> C:\local\boost_1_67_0\boost/compute/iterator/zip_iterator.hpp(276): note: could be 'boost::compute::zip_iterator,boost::compute::buffer_iterator,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>> boost::compute::make_zip_iterator,boost::compute::buffer_iterator,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>(IteratorTuple)' 1> with 1> [ Thanks, Madison

2 2

[boostbook] cleanup / modernization
by James E. King III 18 Jul '18

18 Jul '18

I would have opened an "issue" on the boostorg/boostbook project, however, that is not enabled. (Perhaps someone should enable it?) I have duplicated the boostbook setup scripts into the docker setup environment for Ubuntu Bionic and I have found that all of the packages that boostbook depends on are ancient. PackageVersionLast ModifiedHost docbook-xsl 1.75.2 2009 SourceForge <http://sourceforge.net/projects/docbook/files/docbook-xsl/1.75.2/docbook-xs…> docbook-xml 4.2 2002 oasis-open.org <http://www.oasis-open.org/docbook/xml/4.2/docbook-xml-4.2.zip> fop 0.94 2007 Apache <http://archive.apache.org/dist/xmlgraphics/fop/binaries/fop-0.94-bin-jdk1.4…> These tools are quite old and it is only a matter of time before the older versions could be removed. These external sites are under no particular requirement to keep these older versions of software available. At some point some of these tools may no longer work with current operating system tools, for example "fop" says that it is for "JDK 1.4". Each of these tools has a newer version. A project should be initiated now to modernize the documentation build to use more recent versions of these tools before it becomes a critical release blocker at a bad time. - Jim

3 2

[iostreams] libstdc++ vs MSVC exception handling behavior in seekg, seekp
by James E. King III 17 Jul '18

17 Jul '18

I found a disabled test in Boost.Iostreams called stream_state_test. It was disabled because it was thought it only tests the standard library implementation. Partially true, but it also tests some parts of iostreams so I have been working to re-enable it along with the generic CI upgrades. It looks like libstdc++ and the standard library that comes with MSVC (is it still Dinkumware? It used to be...) handle exceptions on stream seekg and seekp differently. I haven't consulted the standards documents yet, but I found this reference for exception handling: http://www.cplusplus.com/reference/istream/istream/seekg/ which states, " Any exception thrown by an internal operation is caught and handled by the function, setting badbit <http://www.cplusplus.com/ios_base::badbit>. " Sitting in the debugger where the test throws an exception in error_device::seek, there is no exception handling within iostreams or in msvcp140d code paths for a call to seekg, while the libstdc++ implementation is able to pass all of the tests. This leads to a couple questions: 1. Are the standards clear in this area? 2. Is someone violating them? A cursory review (such as this) leads me to believe that the MSVC C++ runtime implementation is not properly handling exceptions here. The sources for seekg in libstdc++ wrap the internals in a try catch in order to restore state. The sources for seekg in the MSVCPRT do not. - Jim

2 1

Safe Float design question
by Damian Vicino 17 Jul '18

17 Jul '18

Hi, I looking for some design advice. The context: - I'm revisiting SafeFloat after some time and, while doing so, I'm rethinking all the decisions from the past. Idea is to sent for review in the following months. - The goal of the library is being a drop-in replacement for float, that adds checks to floating point operations and reports when a check failed. Without SafeFloat, someone could write something like this: #include <iostream> #include <limits> #include <cfenv> using namespace std; int main(){ float a = 1.0f; float b = numeric_limits<float>::max(); feclearexcept(FE_ALL_EXCEPT); float c = a/b; if(fetestexcept(FE_UNDERFLOW)) { cout << "underflow result\n"; } } What I expect when using safe_float is to declare upfront "what checks" I care about, "what operations" to check, and "what to do when a check fails". Some intention examples: - I would like to check there was no "overflow_to_infinite" in "addition operations", otherwise I "throw exception".. - I would like to check there was no "division by zero" in "division", otherwise I will "log to cerr and ignore it". - I would like to check there was no "inexact" "addition", otherwise I return an boost::unexpected. I have at least 5 things to check (there is 5 flags in c++11::fenv). I have at least 4 places to check (+/-/*//) and I want to keep what to do about it customizable. In addition, sometimes I want to check multiple things "overflow and underflow", etc... So, the question is how the user can pass all that information to the type and it doesn't look as horrible nonsense. My original option was: int main(){ using CHECK = compose_policy<check_addition_overflow, check_division_by_zero, check_division_underflow>::type; using REPORT = report_throw_on_failure; using sf = safe_float<float, CHECK, REPORT>; try{ sf a = 1.0_sf; sf b = numeric_limits<sf>::max(); auto c = a/b; } catch (safe_float_exception e){ cout << e.message(); //this outputs there was a underflow } } Please comment in what you think about this way to use. Is there a better way to specify the policies to apply that I should try? Best regards, Damian I expect when using safe float to write some code like this: int main(){ safe_float<float> }

2 3

[system] Clang CI builds broken because of constexpr
by Andrey Semashev 17 Jul '18

17 Jul '18

Hi, I'm seeing these errors in Travis CI builds with Clang 3.8, 3.9, 4.0 and 5.0: ./boost/system/error_code.hpp:232:41: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr] BOOST_SYSTEM_CONSTEXPR explicit std_category( boost::system::error_category const * pc ): pc_( pc ) ^ ./boost/system/error_code.hpp:232:41: note: non-constexpr constructor 'error_category' cannot be used in a constant expression /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/system_error:69:5: note: declared here error_category() noexcept; ^ I'm assuming this is because the compiler uses libstdc++ from gcc 4.8, in which error_category() is not marked constexpr. Can this be fixed somehow?

1 0

[graph] disjoint_sets
by James E. King III 17 Jul '18

17 Jul '18

Hello folks in the Boost.Graph team, The CMT currently maintains Boost.DisjointSets which contains a class that is only used by Boost.Graph and Boost.GraphParallel. The headers are published in "boost/pending" right now. Given the CMT has a considerable workload already I would like to discuss moving disjoint_sets into Boost.Graph, as long as it satisfies the requirements for the two repositories currently consuming it. This would be for 1.69.0. Any thoughts, objections, considerations on this (open to anyone)? Thanks, Jim

2 3

Heads up about future standards annexing new identifiers
by Marshall Clow 16 Jul '18

16 Jul '18

As facilities get added to the standard library, they need names. When this happens, it restricts what other developers can and cannot do in their programs. For example, one cannot do this and expect most anything in the standard library to work: #define allocate(T) . new T [ But you knew about that ]. What you may not have known about was that the standards committee has voted contract enforcement/checking facilities into the draft standard (which will probably be C++20). This includes attributes named: 'expects' and 'ensures'. (all lower case) I have checked all of boost, and with the possible exception of Boost.Contract, we do not have any macros with those names. But you might want to keep your eyes open. -- Marshall P.S. These are not keywords - so it's perfectly fine to have member functions with these names. Variables, too. Probably even free functions - though I haven't tried that. But macros are right out ;-) P.P.S. For people who are interested, the paper is http://wg21.link/P0542

2 1

Searching for a intrusive::avltree_algorithms/bstree_algorithms dev
by Thimothée Virgoulay 16 Jul '18

16 Jul '18

Hello I'm working with the boost library (intrusive: : avltree_algorithms/bstree_algorithms ) and I found some bugs (not sure, maybe it's me who haven't understood the algorithm logic ). I have made hotfixes , add functions and it's working. But I don't know if this change were fine or needed. So I 'm searching for someone who can exchange with me about this library. Thimothée Virgoulay, second's year master degree in Bioinformatics at Montpellier University, France.

4 3

[rational] 1.68.0 merge permission
by James E. King III 16 Jul '18

16 Jul '18

The addition of pow() for rational was identified as a problem in beta testing. It has been reverted for now, and an issue added to the github repository to revisit it after 1.68.0. There are two commits I would like to merge to master: 1. The revert of pow which caused problems 2. A CI-only change to .travis.yml that fixes codecov.io and coverity scan build jobs in light of recent security upgrades in travis CI. No production code changes, zero affect on the release build workflow. This will allow the build status to remain green for the repository as it is merged to master. Thanks, Jim

2 1

[CMT] 1.68.0 merge permission
by James E. King III 16 Jul '18

16 Jul '18

The CI builds in CMT repositories are failing since Travis CI updated their backend last week. The fix is simple and isolated in the .travis.yml file in each repository which is not part of the boost release build cycle. All repositories develop branch have been updated with the fix. I'd like to merge the fix in the CMT repositories into master to eliminate the remaining failed build indicators. Given the change is only in .travis.yml I hope that will be acceptable. Without the fix any cron job on master in these repositories will fail in codecov.io and covscan. Thanks, Jim

2 1

Invalid arguments
by randy 16 Jul '18

16 Jul '18

I’ve the following function but i get invalid arguments error , can please someone tell me where’s this invalid param or argument : int Asio_Send_Pck(int iSendt,int Lsocket,char * Lbuff,int Len) { session* iTempSession = reinterpret_cast<session*>(Lsocket); boost::asio::async_write(iTempSession->socket() , boost::asio::buffer(Lbuff, Len), boost::bind(&session::handle_write, iTempSession, boost::asio::placeholders::error, iTempSession->data, iSendt )); return 0; };

2 1

Boost.Signals deprecation and removal
by James E. King, III 15 Jul '18

15 Jul '18

This first implementation of signals has been deprecated since the 1.54 release. (When) are we going to remove it? It is under management of the CMT, and it has been deprecated for over 10 major releases. I would like to suggest we remove it in the Boost 1.68.0 release. - Jim

9 9

Reporting accurate code coverage
by James E. King III 13 Jul '18

13 Jul '18

General Code Coverage Tip (for everyone): Measure your coverage using branches, not lines. Branch coverage tells you how well error cases are tested and therefore a far better measure of quality than line-based. I have seen over 90% line coverage but the branch coverage is more like 60% to 70% on average over the boost CMT-managed repositories. Here's the shell script I use on travis to generate the data and feed it to codecov.io: https://github.com/jeking3/boost-ci/blob/master/ci/travis/codecov.sh The trick is to feed --rc lcov_branch_coverage=1 to the correct commands to generate and preserve the branch information. Thanks, - Jim

3 3

[boost-ci] code coverage build fix
by James E. King III 13 Jul '18

13 Jul '18

For folks using boost-ci integration, here is a fix to your .travis.yml file to enable code coverage builds to work again. I received confirmation from Travis CI that a back-end update on their end corrected some security issues which necessitates this change. https://github.com/boostorg/rational/pull/22/files In the script section of the coverage job, replace the commands: cd lcov && sudo make install with: export PATH=/tmp/lcov/bin:$PATH Thanks, Jim

1 0

[boost-ci] codecov.io integration
by James E. King III 13 Jul '18

13 Jul '18

Folks using boost-ci integration may see the code coverage builds failing. Part of the .travis.yml script includes logic to update lcov to a newer version for branch coverage to work. These build jobs are breaking due to enforcement of the sudo restriction. I am working on a way to fix this and will send out an update when I have a solution. - Jim

1 0

[Range] 1.68 master/beta MSVC compilation error with /fpermissive-
by Vinnie Falco 13 Jul '18

13 Jul '18

When compiling using /fpermissive- (enable strict conformance) I get the following compilation error: boost\boost\range\concepts.hpp(257): error C3646: 'n': unknown override specifier boost\boost\range\concepts.hpp(264): note: see reference to class template instantiation 'boost::range_detail::RandomAccessIteratorConcept<Iterator>' being compiled boost\libs\beast\include\boost\beast\core\string.hpp(87): note: see reference to class template instantiation 'boost::basic_string_view<char,std::char_traits<char>>' being compiled boost\boost\range\concepts.hpp(257): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int boost\boost\range\concepts.hpp(257): error C3646: 'n': unknown override specifier boost\boost\range\concepts.hpp(264): note: see reference to class template instantiation 'boost::range_detail::RandomAccessIteratorConcept<Iterator>' being compiled I'm using the tip of master, digest 000bd8507f8a17ada2c1fef19158e16cdeabd631 Thanks

6 14

[Boost.Serialization] Help with PR fixing a memory leak in the current version
by Alexander Grund 12 Jul '18

12 Jul '18

Hi, TLDR: I would like https://github.com/boostorg/serialization/pull/105 to be merged for the next Boost release to fix a memory leak and need someone to review this or help getting it merge-ready. Details: Some time ago I made an analysis of a crash introduced in Boost 1.65.0 in the serialization part. The details are quite complicated as the cause is static initialization/destruction order in shared libraries which may even depend on compilers (could not confirm) or standard libraries (dito, observed in all tested versions). It boils down to a violation of the expected destruction order in the case of shared libraries. I observed how 2 global instances of the same type but from different shared libs are destroyed together although the 2nd should not yet be which causes a use-after-free from another global instance. The Singletons involved did have methods to detect, whether they are active or destroyed but they were kinda optimized away in Boost 1.65 leading to a crash which makes the whole library unusable. Not understanding the root cause of the crash lead to changing the singleton to use dynamic allocation, but not freeing it which leads to the memory leak that is currently in Boost. The current state of the develop-branch changed this back to the crash situation we had before making it unsuitable for the next release. Another pair of eyes would be great to check the PR and get this finally fixed. Thanks, Alex

6 33

[rational, spirit] 1.68.0 beta 2 bug report
by James E. King III 12 Jul '18

12 Jul '18

A bug reported by someone using a version of 1.68.0 (not specified): https://github.com/qtumproject/cpp-eth-qtum/issues/31#issuecomment-404257256 Seems to have something to do with the new pow template that was added to rational. This came from an old pull request that was simplified, however it seems pow is now a template defined in the namespace boost, and seems to have caused some issues. I'd guess this is only an issue inside boost namespace (so all boost headers) and not external namespaces. Not sure at the moment if the fix should be in rational or spirit. We could instead back out the change to rational for 1.68.0 where pow() was added into namespace boost. https://github.com/boostorg/rational/pull/21 - Jim

2 1

boost/context/all.hpp missing in 1.68.0beta1
by Roger Leigh 11 Jul '18

11 Jul '18

Is this intentional, or an unintentional regression? I was using this header in the CMake component checks to verify the presence of Boost.Context, and this is now breaking. I can update it to use a different header which has been present since 1.61, but this seems like a compatibility break, hence the question. Thanks, Roger

2 1

Fwd: [Range] 1.68 master/beta MSVC compilation error with /fpermissive-
by degski 11 Jul '18

11 Jul '18

It did go off-list. ---------- Forwarded message ---------- From: degski <degski(a)gmail.com> Date: 11 July 2018 at 19:16 Subject: Re: [boost] [Range] 1.68 master/beta MSVC compilation error with /fpermissive- To: Mateusz Loskot <mateusz(a)loskot.net> On 11 July 2018 at 18:56, Mateusz Loskot <mateusz(a)loskot.net> wrote: > (was your response intentionally direct and off-list?) > No, not intentionally, but it depends on how you send the email (because I pushed reply), like on this one (it would have gone off-list again). I had to add the mailing list back in. This doesn't happen with most posts. I'm not sure what you mean, but I meant the driver that Vinnie mentioned > I'm not totally sure what Vinnie mentions. But I'm talking about this one for stable <https://releases.llvm.org/6.0.1/LLVM-6.0.1-win64.exe> and this one for (almost) trunk <http://prereleases.llvm.org/win-snapshots/LLVM-7.0.0-r336178-win64.exe>. I have the impression Vinnie is talking about Clang/C2 <https://blogs.msdn.microsoft.com/vcblog/2016/04/06/clangc2-we-need-your-adv…>, but like I said it's not clear to me, that compiler, however, is discontinued. degski --- *"If something cannot go on forever, it will stop" - Herbert Stein*

1 0

[Histogram] Status of the review schedule
by Mateusz Loskot 11 Jul '18

11 Jul '18

Hi, Following some discussion in January this year, Hans Dembinski's Histogram library was scheduled for review in March. AFAICT, no review happened. What is the current status of the proposal? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 4

[geometry][units]
by Pranam Lashkari 11 Jul '18

11 Jul '18

I am trying to use boost.geometry with the integration of boost.units. What I want to do is store a coordinate point (e.g: Cartesian or spherical) which should be unit safe.(e.g a cartesian point with length unit meter should give error with cross product is done with cartesian point with length unit millimeter). For this I am using boost::geometry::model::point. Problems I am facing: 1. If I use something like boost::geometry::model::point<UnitClass, 3 ,boost::geometry::cs::cartesian> then all the operations like cross product and dot product will fail as units can not be multiplied and if we multiply then dimensions and units will change. 2. suppose I want to use spherical 3d coordinate then boost::geometry::model::point is cable accommodate only one type of class for all the underlying dimension(eg: distance, longitude and latitude). But in real case distance should be in length and longitude and latitude should be in angle unit. Is there any way to integrate boost.units with boost.geometry for the purpose I mentioned above. Thank you, Pranam Lashkari

1 0

Boost.Graph depth_first_visit algorithm
by Brook Milligan 09 Jul '18

09 Jul '18

The documentation on the Boost.Graph depth_first_visit algorithm indicates that the first argument is a non-const reference to an Incidence Graph. See https://www.boost.org/doc/libs/1_67_0/libs/graph/doc/depth_first_visit.html. However, in contrast the code in boost/graph/depth_first_search.hpp only implements the function for a _const_ reference to an Incidence Graph. I can see that changing the graph structure mid-traversal is a problem, but I have use cases in which graph properties (not graph structure) must be changed along the traversal. Thus, it seems that a valid use case is for this algorithm to work as documented, i.e., on a non-const graph. The attached patch implements overloads for the non-const versions of depth_first_{visit|search}, including overloads for the dfs_visitor member functions. Is there some reason not to extend the implemented interface in this way to better agree with the documentation? Cheers, Brook

1 0

Clang 600 and BOOST_SYSTEM_CONSTEXPR causes error_code.hpp compile failure.
by Paul A. Bristow 09 Jul '18

09 Jul '18

Having failed to build Boost libraries using Clang 6.0.0 using b2/bjam on Windows, I am now trying instead to use Codeblocks on Windows 10 to build static libraries. It comes to grief with these messages (the berbose gory details can be posted if anyone can help). In file included from I:\modular-boost\boost/system/system_error.hpp:14: I:\modular-boost\boost/system/error_code.hpp:409:88: error: variable does not have a constant initializer template<class T> BOOST_SYSTEM_REQUIRE_CONST_INIT system_error_category cat_holder<T>::system_category_instance; ^~~~~~~~~~~~~~~~~~~~~~~~ I:\modular-boost\boost/system/error_code.hpp:409:19: note: required by 'require_constant_initialization' attribute here template<class T> BOOST_SYSTEM_REQUIRE_CONST_INIT system_error_category cat_holder<T>::system_category_instance; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I:\modular-boost\boost/system/error_code.hpp:392:44: note: expanded from macro 'BOOST_SYSTEM_REQUIRE_CONST_INIT' # define BOOST_SYSTEM_REQUIRE_CONST_INIT [[clang::require_constant_initialization]] ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This seems to be the ultimate cause I:\modular-boost\boost/system/error_code.hpp:226:41: note: non-constexpr constructor 'error_category' cannot be used in a constant expression BOOST_SYSTEM_CONSTEXPR explicit std_category( boost::system::error_category const * pc ): pc_( pc ) Is this because BOOST_SYSTEM_CONSTEXPR should not be defined? I note this in error_code.hpp #if defined(__GNUC__) && (__GNUC__ == 7 || __GNUC__ == 8) && __cplusplus >= 201700L // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83835 # undef BOOST_SYSTEM_HAS_CONSTEXPR #endif should this undef list also include clang, and if so which versions 600? Or is there something about Boost.config and Codeblocks on Windows? Adding unconditional # undef BOOST_SYSTEM_HAS_CONSTEXPR seems to work. Suggestions welcome. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

7 13

toolset=clang-win uses clang-linux-win?
by Peter Dimov 09 Jul '18

09 Jul '18

When I try `b2 toolset=clang-win` on Appveyor, I get `clang-linux-win` instead, that is, `-win` is interpreted as version for some reason, not as platform: https://ci.appveyor.com/project/pdimov/system/build/job/sjpdq5yrir2ewuhh Is this normal, or is it a bug in the clang toolset? Is there a magic command line incantation that would let me select clang-win?

3 7

[Boost Build] clang-win, <compatibility> property?
by degski 08 Jul '18

08 Jul '18

error: Please set <compatibility> property for visual studio version! How and to what value (VS2017 - 15.7.4, Compiler Version 19.14.26431 ) do I set the <compatibility> property using a project-config.jam file? The documentation <https://boostorg.github.io/build/manual/develop/index.html#bbv2.reference.t…> does not list clang at all, which probably means it works like gcc, there is obviously no <compatibility> property there. Help would be appreciated, then I can post some build results of 1.68-rc2. degski -- *"If something cannot go on forever, it will stop" - Herbert Stein*

1 0

python::numpy not built on windows binary installers
by Nicholas Devenish 07 Jul '18

07 Jul '18

Hi All, I just downloaded the windows boost binaries from https://dl.bintray.com/boostorg/release/1.67.0/binaries/, linked from the boost downloads page. They are missing the boost_numpy library. This (silently) doesn't build if the python installation that boost finds is missing numpy. This is listed as "Third Party" so apologies if this is the wrong place to report it - but it's not clear from the page who makes them. I also couldn't find any mention of this, so don't know if it's a deliberate exclusion. Nick

2 3

[release] Boost 1.68.0 Beta 1 Release Candidate 2
by Marshall Clow 07 Jul '18

07 Jul '18

The release candidates for the second 1.68.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.68.0.beta1.rc2/source/> The release notes are not yet available. The updated documentation is not yet available. [ They will be available in a day or two. ] == Changes since RC1: * version.hpp now has the correct version number in it. * Boost.Wave now builds on FreeBSD * Boost.ProgramOptions should now pass tests on msvc-10.0. The SHA256 checksums are as follows: 961d2bdc74c1499c931b32098842abba8883b1a89ef5c8f8f0ab0aff771a3ce5 boost_1_68_0_b1_rc2.7z 0364846258648e39908ca7cebfc2d2216eef6980c32aaf8276d2cfe73ef012e3 boost_1_68_0_b1_rc2.tar.bz2 d99105685a68907a76b0479ecde77915423246236ef0db9cb846c5bfc09b41f3 boost_1_68_0_b1_rc2.tar.gz 6158e0e961bfb0d8adeb2ea70337b08504668258025f0a873fb21eee3436d22e boost_1_68_0_b1_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. -- The Boost Release Managers

2 4

[iostreams] Merging to master
by Edward Diener 07 Jul '18

07 Jul '18

I would like to merge the iostream changes on 'develop' to 'master'. They are all green on the 'develop' tests, and have been tested for awhile now, and I have just been lax getting these to the 'master' branch.

3 4

[1.68.0 Beta1 RC1][iostreams][vs2017 preview] seekpos is not a member of std::pos
by Mateusz Loskot 07 Jul '18

07 Jul '18

Hi, I'm trying to build some of Boost libraries with the very latest VS 2017 Version 15.8.0 Preview 3.0 I've changed project-config.jam to point msvc-14.1 to the corresponding CL.EXE ``` using msvc : 14.1 : "c:\Program Files (x86)\Microsoft Visual Studio\Preview\Professional\VC\Tools\MSVC\14.15.26608\bin\HostX64\x64\cl.EXE" ; ``` In "x64 Native Tools Command Prompt for VS 2017 Preview", I do ``` .\bootstrap.bat b2 -j8 toolset=msvc-14.1 address-model=64 variant=release --with-iostreams ... compile-c-c++ bin.v2\libs\iostreams\build\msvc-14.1\release\address-model-64\link-static\threading-multi\file_descriptor.obj file_descriptor.cpp .\boost/iostreams/positioning.hpp(96): error C2039: 'seekpos': is not a member of 'std::fpos<_Mbstatet>' c:\Program Files (x86)\Microsoft Visual Studio\Preview\Professional\VC\Tools\MSVC\14.15.26608\include\iosfwd(132): note: see declaration of 'std::fpos<_Mbstatet>' ``` Is this expected? Shouldn't this be fixed by https://github.com/boostorg/iostreams/pull/57 ? Or the PR has not made it into the master? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 4

[Boost PP] MSVC PP Updated Info
by degski 07 Jul '18

07 Jul '18

More info <https://blogs.msdn.microsoft.com/vcblog/2018/07/06/msvc-preprocessor-progre…> . degski -- *"If something cannot go on forever, it will stop" - Herbert Stein*

1 0

[release] Boost 1.68.0 Beta 1 Release Candidate 1
by Marshall Clow 07 Jul '18

07 Jul '18

The release candidates for the first 1.68.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.68.0.beta.1.rc1/source/> The release notes are not yet available. The updated documentation is not yet available. [ They will be available in a day or two. ] The SHA256 checksums are as follows: 4b39978aa227f56cc00715d48032e18f4bb259de756637a653b5acead4417e0b boost_1_68_0_b1_rc1.7z 39f6fdc16fc62041ca1401c5e8d1cd0220de24fd5d909eca3f0bf1049d1fd6f9 boost_1_68_0_b1_rc1.tar.bz2 9714d11a205e6f3a1cf1ed17b0caad8a64bc4a5459dfc6e1629e14e5e4b44dc7 boost_1_68_0_b1_rc1.tar.gz fe35f20eb5c2ebf5d4e4f15d0416e484058a732ca1a1e59b831b79d4d7702bdd boost_1_68_0_b1_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. -- The Boost Release Managers

5 10

Error in ublas map_array doc
by Dick Hadsell 06 Jul '18

06 Jul '18

I was looking for a function to return the capacity of a Boost uBLAS map_array, so I checked the docs online. When I looked at this page: https://www.boost.org/doc/libs/1_67_0/libs/numeric/ublas/doc/index.html I found in the table of member functions two entries for the size() function, but one should clearly be the capacity() function. I confirmed in our headers that it exists. -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

1 0

[release] 1.68.0 closed for Beta
by Marshall Clow 06 Jul '18

06 Jul '18

The master branch is now closed for all changes except by permission for the Beta release. Also, remember to add your libraries' changes to the release notes at: < https://github.com/boostorg/website/blob/master/feed/history/boost_1_68_0.q… > Thanks, -- The Boost Release Team

4 5

[MultiIndex] Hinted insertion for multiple indices?
by Gareth.Sylvester-Bradley＠sony.com 04 Jul '18

04 Jul '18

Is there a way to provide insertion hints for multiple indices in a multi_index_container? In a particular example, I have a container with several ordered_non_unique indices, and for the majority of insertions, the value will end up at the end of these indices. I'm looking for a way to provide the index.end() hint for all of these indices? (Or maybe alternatively, to relax the stability/insertion-order guarantee?) Thanks, Gareth

2 3

[ASIO] Clarification regarding socket release on Windows
by Gyorgy Szekely 04 Jul '18

04 Jul '18

Hi, The documentation (boost 1.67) of asio::basic_stream_socket::release() has the following remark: *This function is unsupported on Windows versions prior to Windows 8.1, and will fail with boost::asio::error::operation_not_supported on these platforms.* This is in accordance with the compiler warning I get when building my project (from asio basic_socket.hpp), and the runtime behavior: the native socket ownership is indeed retained by asio. For the IOCP backend! If I add the BOOST_ASIO_DISABLE_IOCP define to the build I still get the warning, but the release() appears to be working: the ownership is released and I can do whatever I want with the socket. My question: does the above comment apply only to the IOCP backend and I can use release() with the reactive socket service? Or it just happens to be working in my current setup but it's not guaranteed for others (or it leaks resources, etc...)? Regards, Gyorgy

1 0

[beast] warning
by Vinnie Falco 04 Jul '18

04 Jul '18

I'd like to merge to master, this tiny fix for a warning: <https://github.com/boostorg/beast/pull/1175> The OSX build failure is spurious and unrelated Thanks

1 0

Boost linked example
by degski 03 Jul '18

03 Jul '18

Could someone, please, point me to an example (in the Boost source, i.e. a file in the libs sub-folder) that would require (with certainty) a built library. Which library don't matter. I've tried some date-time examples and boost::random::random_device, but it works, while I hoped it wouldn't. The latter can also mean I have some strays, but then I know that. I would like to check vcpkg static-static linking for Boost. Thanks, degski -- *"If something cannot go on forever, it will stop" - Herbert Stein*

2 4

CMT Library and CI Status for Boost 1.68.0
by James E. King III 01 Jul '18

01 Jul '18

I have been working on adding CI to the CMT libraries (and a few others). This provides improved quality and metrics for each repository with builds for various linux and windows combinations, as well as code coverage and static code analysis with coverity scan. Here is the current status for work that will make it into 1.68.0: The CI framework I have been adding is here: https://github.com/jeking3/boost-ci CI has been enabled on the following repositories (and any identified defects have been resolved) and is passing: function, mpl, pool, property_map, ptr_container, rational, tokenizer In addition, Boost.Move and Boost.Signals2 are also now using this framework to improve deliverable quality. CI not yet enabled on (and reasons): Boost.Assign fails to compile <https://github.com/boostorg/assign/pull/16> with MSVC 2012 in Appveyor. Boost.ConceptCheck fails to compile <https://github.com/boostorg/concept_check/pull/13> on most compilers in Travis CI and Appveyor. (It looks like it's unusable.) Boost.DisjointSets - status unknown (no CI) - open question still unanswered: Can we merge this into container? It is only used by graph and graph_parallel. Boost.DynamicBitset fails to compile <https://github.com/boostorg/dynamic_bitset/pull/23> on all MSVC and on linux with c++03 mode. Boost.Interval (numeric/interval) fails to compile <https://github.com/boostorg/interval/pull/14> - most combinations fail and may go into an infinite loop in some cases. Boost.Logic (tribool) uncovered issue #8 <https://github.com/boostorg/logic/issues/8>. Boost.Signals - we discussed a removal notification in an upcoming release but no action has been taken by the CMT yet to make this happen so it may slip into the next release. Boost.Statechart needs some Jamfile help to get it to work with this CI infrastructure. I am most concerned about Boost.ConceptCheck and Boost.Interval. Both may be unusable at this point. If folks have any spare cycles and care to take a look, it would be appreciated. Thanks, Jim

3 3

[config] MSVC feature-test macros
by Stephan T. Lavavej 29 Jun '18

29 Jun '18

Hi Boost devs, FYI, VS 2017 15.8 Preview 3 has been released, with support for feature-test macros. If you want to take advantage of the feature-test macros, please notify me immediately about any problems so I can get them fixed for the production release. Notes: * __has_cpp_attribute is the one thing that isn't supported yet. * There are minor changes coming for the production release of 15.8, notably L suffixing and an increase in the value for __cpp_deduction_guides. * Library macros are defined by including any <meow> or <cmeow> header (but not <meow.h>). <ciso646> is the lightweight way to get all macros. This will be superseded by <version> in C++20, but that is not yet implemented. * The macros are always provided regardless of the /std compiler option. (Of course their definedness and values vary.) * We are defining __cpp_exceptions and __cpp_rtti, although those weren't picked up for C++20. * The only fundamentally new ability that these macros provide is the ability to sense whether thread-safe statics are supported; this was previously controlled by a compiler option, but not reflected in any MSVC-specific macro. * The macros respect all of our compiler options and library control macros - e.g. if std::byte's definition is suppressed (to avoid conflicts with the Windows SDK), then __cpp_lib_byte reflects that. Hope this helps, STL

6 7

[chrono] #13557 Boost 1.67.0 chrono library Windows build installs NTFS junction
by Stephan T. Lavavej 28 Jun '18

28 Jun '18

Hi Boost.Chrono devs, I have some additional information about https://svn.boost.org/trac10/ticket/13557 . (Also tracked at https://github.com/StephanTLavavej/mingw-distro/issues/58 , it affects both MSVC and MinGW.) As Joshua Morrison discovered, copying libs/chrono/stopwatches/include/boost/chrono/. to boost/chrono before building is a workaround that prevents the junction and hardlink from being created. Also, I mentioned this on Twitter and René Rivera said: "Those links are supposed to appear only for the git checkout of @Boost_Libraries and are created on demand when headers are reference during the header scanning. Creating those for a release is a bug in the release process." (https://twitter.com/grafikrobot/status/1011077139511369728 ) I'm still not sure what the correct fix is, but it seems that boost/chrono should contain the stopwatches files, if they're being referenced by other headers. Thanks, STL

2 2

[ Interest? ] [ out_ptr ] Tiny C++ Abstraction for C-Style Output Pointers
by ThePhD 28 Jun '18

28 Jun '18

Dear Boost Community, I was encouraged to submit this small library that I had created as a formal public investigation of the performance and API-interop benefits to the Boost Mailing List, to perhaps see if other people have come up with something similar to this at their own comapnies. 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 design is meant to be extensible by both the library implementer and the user, enabling it to be used with other pointer types that do not originate from either `boost::` or `std::`. The library replaces the sought-after syntax of: my_c_api_init( foo, bar, &my_start_ptr ); with a free function that does not impose on the interface of the smart pointer: my_c_api_init( foo, bar, out_ptr( my_smart_ptr ) ); This makes it possible to use a temporary return value to give a reference to a pointer value that then performs a reset on the smart pointer. Is there any want for something like this? I know it has seen use at companies and Studios I have worked in and interacted with, including Microsoft and VMWare. std::retain_ptr's author also has a need for this to make interop easier with reference-counting C APIs and beyond, and I myself implemented something like it 5 years ago and have been using it ever since. Sincerely, JeanHeyd P.S.: this is also going to end up going in the Post-Rapperswil Standards C++ Mailing as well. The proposal is also contained in the repository: https://rawgit.com/ThePhD/out_ptr/master/papers/d1132.html

1 0

[release] 1.68.0 closed for major changes
by Marshall Clow 28 Jun '18

28 Jun '18

The master branch is now closed for new libraries and breaking changes, and will be closing for the beta in one week. Also, if you're ready, you can also add your libraries' changes to the release notes at: <https://github.com/boostorg/website/blob/master/feed/ history/boost_1_68_0.qbk> After editing the release notes, you should get a form to create a pull request, remember to submit it, otherwise I won't see your change. Thanks, -- The Boost Release Team

1 0

[Boost PP] MSVC PP
by degski 28 Jun '18

28 Jun '18

We seem to be getting there. Visual Studio 2017 version 15.8 Preview 3 Announcement <https://blogs.msdn.microsoft.com/visualstudio/2018/06/26/visual-studio-2017…> tl:dr: "*C++ Standards:* A new, experimental, token-based preprocessor that conforms to C++11 standards (including C99 preprocessor features), enabled with /experimental:preprocessor switch. This will be controlled with macro _ *MSVC*_TRADITIONAL, which will be defined to 1 when using the traditional preprocessor and 0 when using the new experimental standards conformant preprocessor." degski -- *"If something cannot go on forever, it will stop" - Herbert Stein*

4 4

[release]
by Zach Laine 27 Jun '18

27 Jun '18

I'm seeing a difference in the Yap Quickbook build in a local checkout of boost-with-submodules, develop branch, and the Circle CI develop build. The auto-index seems to be wrong in the Circle CI one: https://www.boost.org/doc/libs/develop/doc/html/yap.html Note that the stuff at the bottom of that page refers to content in other libs. The Reference section also points to the wrong stuff in the .hpp detail pages. When I originally moved Yap over to Boostorg, I did not initially update all the paths correctly for an integrated Boost build; I was doing a standalone doc build. I have since fixed the paths, and I see the right index and Reference sections when I build locally. I suspect that the Circle CI cache has some files lying around that are causing this problem, but I don't really know. Does anyone have any insight into this problem? Does anyone have admin rights to do a Circle CI rebuild-without-cache? Thanks, Zach

1 0

[Library idea] Type-safe Flagsets
by Julien Vernay 27 Jun '18

27 Jun '18

Hello everybody, I want to know if some people are interested in a type-safe flagsets. I define flagsets as a container similar to a bitset, but where each bit has a meaning. For example, we could have in some game : enum Direction : unsigned { UP = 0b0001, DOWN = 0b0010, LEFT = 0b0100, RIGHT = 0b1000 }; ... unsigned player_dir = UP | RIGHT; if ((player_dir & (UP|LEFT)) == (UP|LEFT)) player.setAnim("up_left"); player_dir &= ~UP; //removing UP from player_dir I think there are some issues with this kind of flagset : - you need to think about power-of-twos when attributing values to your flags. - you need to use bitwise operations which can be non-trivial, even for removing only one flag. - it is not safe: for example with another flagset using the flag INIT_VIDEO (in a window library like SDL), you can do " UP | INIT_VIDEO " even if the two flagsets have nothing in common With a type-safe flagset library, this code would become : namespace Direction { struct UP; struct DOWN; struct LEFT; struct RIGHT; using Type = flagset<unsigned, UP, DOWN, LEFT, RIGHT>; //unsigned is the underlying type }; ... auto player_dir = Direction::Type::Value<Direction::UP, Direction::RIGHT>(); if (player_dir.allOf<Direction::UP,Direction::LEFT>()) player.setAnim("up_left"); player_dir.reset<Direction::UP>(); It is more verbose but also more safe and easy to use. I actually have a partial implementation on GitHub, supporting read, write and conversions to strings : https://github.com/J-Vernay/flagset I would like to know if some people are interested in this kind of library, and if yes, what they think about the current syntax/implementation. Thanks for reading !

3 8

Re: [boost] On Boost's logo copyright
by Mateusz Loskot 25 Jun '18

25 Jun '18

(CC to boost(a)lists.boost.org) On 25 June 2018 at 22:03, Giovanni Mascellani <gio(a)debian.org> wrote: > Il 25/06/2018 14:33, Mateusz Loskot via Boost ha scritto: >> AFAICT, the logo design was established around Boost 1.33. >> Here is related note from the release notes [1] >> >> ``` >> Rene Rivera for the new Boost web page design; and Zoltan >> "cad" Juhasz for the new Boost logo. >> ``` > > This is very useful, thank you! You're welcome. I hope I've pulled the actual facts. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

1 0

On Boost's logo copyright
by Giovanni Mascellani 25 Jun '18

25 Jun '18

Dear Boost developers, I am preparing the next upload of Boost package in Debian. I would appreciate your help on a little detail, which is however very important for Debian (if this is not the right place to ask, please accept my apologies and direct me to a more appropriate one): who is the copyright holder of Boost's logo? I understand that it is licensed under the BSL license, but it seems to me that the name of the rights holder is not listed anywhere. Thanks for your help and for the great library, Giovanni. -- Giovanni Mascellani <g.mascellani(a)gmail.com> Postdoc researcher - Université Libre de Bruxelles

2 1

[release][yap] Master archive builds broken.. for a long time.
by Rene Rivera 24 Jun '18

24 Jun '18

While checking to see that the master PRs I did yesterday to master where not causing problems I noticed something unrelated. Looks like the master archive build has been failing for a long time now. Seems the addition of YAP is broken. It appears there's some documentation files missing: /home/ubuntu/build/boost/bin.v2/doc/gcc-4.8/debug/auto-index-on/threadapi-pthread/src/boost.auto_index.docbook:65535: element include: XInclude error : could not load /home/ubuntu/build/boost/bin.v2/doc/gcc-4.8/debug/auto-index-on/threadapi-pthread/home/ubuntu/boost/libs/yap/doc/yap_reference.xml, and no fallback was found >From any of the builds in < https://circleci.com/gh/boostorg/boost/tree/master>. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

2 4

[math] policy<discrete_quantile<real> > test's fail because multiple matches for 'real'
by Brian Kuhl 24 Jun '18

24 Jun '18

When I compile with VxWorks 7/Clang v5/ Dinkum 700 there is an inline real() function in global scope. Leading to a few errors like this: ----------------------------------------------------------------------- clang-vxworks.compile.c++ ../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o "/yow-build40-lx1/bkuhl/vx7/compilers/llvm-5.0.0.3/LINUX386/bin/clang" -x c++ --target=x86_64 -m64 -mcmodel=large -fno-omit-frame-pointer -fno-strict-aliasing -mno-implicit-float -fno-builtin -nostdlibinc -nostdinc++ -fno-use-init-array -ftls-model=local-exec -ansi -std=c++14 -O2 -Wall -Wno-missing-braces -Wreturn-type -Wconversion -Wformat -Wno-sign-conversion -Wno-c++11-narrowing -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/system -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -O0 -fno-inline -Wall -g -include/yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0/autoconf_vsbConfig_quote.h -D_C99 -D_HAS_C9X -D__vxworks -D__VXWORKS__ -D__RTP__ -D__ELF__ -D__WRS_NO_DIRECT_TLS_ACCESS_FROM_RTP_TO_SHARED_LIB -I/yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0 @/yow-build40-lx1/bkuhl/workspace/VSB/mk/_vsbuinc_cmdllvmBOOST -D_VX_CPU=_VX_SIMLINUX -D_VX_TOOL_FAMILY=llvm -D_VX_TOOL=llvm -D_nq_VSB_CONFIG_FILE=/yow-build40-lx1/bkuhl/workspace/VSB/h/config/vsbConfig.h -I/yow-build40-lx1/bkuhl/workspace/VSB/share/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/system -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -D_VSB_PUBLIC_HDR_DIR=/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -I. -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_TEST_NO_AUTO_LINK=1 -DBOOST_TIMER_STATIC_LINK=1 -DBOOST_UBLAS_UNSUPPORTED_COMPILER=0 -DTEST_FLOAT -I".." -I"../libs/math/include_private" -I"../libs/math/test" -c -o "../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o" "../libs/math/test/test_poisson.cpp" ../libs/math/test/test_poisson.cpp:454:39: error: reference to 'real' is ambiguous typedef policy<discrete_quantile<real> > P1; ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:689:21: note: candidate found by name lookup is 'real' inline long double real(_Lcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:543:14: note: candidate found by name lookup is 'real' inline float real(_Fcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:397:15: note: candidate found by name lookup is 'real' inline double real(_Dcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0/boost/math/policies/policy.hpp:225:4: note: candidate found by name lookup is 'boost::math::policies::discrete_quantile_policy_type::real' real, ^ ../libs/math/test/test_poisson.cpp:454:39: error: unknown type name 'real' typedef policy<discrete_quantile<real> > P1; ^ ../libs/math/test/test_poisson.cpp:454:45: error: expected a type typedef policy<discrete_quantile<real> > P1; ^ 3 errors generated. ...failed clang-vxworks.compile.c++ ../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o... -------------------------------------------------------- I'd like to contribute a pull request to resolve this. But I'd like some guidance; is a simple change that qualifies real acceptable. using namespace boost::math::policies; - typedef policy<discrete_quantile<real> > P1; + typedef policy<discrete_quantile<boost::math::policies::real> > P1; typedef policy<discrete_quantile<integer_round_down> > P2; Or is this something that should be added with #ifdef __VXWORKS__

2 1

Re: [boost] Boost.Signals deprecation and removal
by Mike 22 Jun '18

22 Jun '18

> Isn't deprecation the warning? That depends on what deprecation means. Currently the warning message just says: > [1]Boost.Signals is no longer being maintained and is now deprecated. [...] No mention of removal. The documentation even says > If you have existing [2]Boost.Signals-based code, it **will continue to work**, but consider moving to Boost.Signals2.Â Best Mike References 1. http://Boost.Signals/ 2. http://Boost.Signals/

6 6

[release] 1.68.0 closing for major changes next week
by Marshall Clow 21 Jun '18

21 Jun '18

One week from tomorrow master will closed for major changes. Upcoming dates: * 27-Jun: Boost 1.68.0 closed for major code changes * 4-Jul: Boost 1.68.0 closed for beta * 11-Jul: Boost 1.68.0 beta 1 * 1-Aug: Boost 1.68.0 closed for release * 4-Aug: Boost 1.68.0 release -- The Boost Release Team

2 1

[Build] Create test with shared library linked against current Boost link-variant
by Alexander Grund 18 Jun '18

18 Jun '18

Hi, I discovered a severe bug in Boost.Serialization and am trying to contribute a test to the test suite to reproduce that behavior. I have a minimum example which runs into this (see also https://stackoverflow.com/questions/50064617/order-of-destruction-for-stati…) but I'm having trouble getting that into the Jamfile. What I need: 2 shared libraries linked against the currently tested Boost link-variant and link those into an executable not linked against Boost. So testcase a) would be against Boost-Shared and b) against Boost-Static. But in all cases the libraries itself must be shared. What I have: lib multi_shared_1 : multi_shared1.cpp ../build//boost_serialization : <link>shared ; lib multi_shared_2 : multi_shared2.cpp ../build//boost_serialization : <link>shared ; ... [ test-bsl-run test_multi_shared_lib : : multi_shared_1 multi_shared_2 ] Problem: This links against Boost-Shared even with "./b2 link=static" My best approach so far is to change "../build//boost_serialization" to "../build//boost_serialization/<link>static" but then I cannot test testcase a) (Boost-Shared) anymore. Also it does link other Boost-Libraries (filesystem, system) shared, not static. Furthermore I'd need to add `-fPIC` to the cxxflags of the boost libraries. This is minor as it can be done in the `.travis` file but I'd rather have it in the Jamfile so it is not missed in other test-environments. How can I achieve this? I'm not to familiar with the Jamfiles so this is basically all I could find so far. Thanks, Alexander Grund

1 1

[container] [flat_map] Sub-optimal behavior when utilized with std::less<>
by Viktor Sehr 16 Jun '18

16 Jun '18

It seems to me that neither boost::flat_map nor boost:flat_set with a custom comparator such as std::less<> behaves like std::set/std::map. This results in unnecessary allocation, in difference from std::map/set when used with a std::string as key for example Example: // Please note that I pretend that "dummy" is large enough to make the std::string utilize the heap. auto set = std::set<std::string, std::less<> >{}; auto n = set.count("dummy"); // No conversion from const char* to std::string auto flatset = boost::container::flat_set<std::string, std::less<> >{}; auto n = flatset.count("dummy"); // const char* is converted to a std::string before comparison, thus resulting in an unnecessary allocation. Is this a known issue intended to be resolved? Looking at the code of STL (which ever version ships with Visual Studio), find, count etc has been extended with template key types in addition to the regular key_type using an "is_transparent" trait: template<class _Other, class _Mycomp = key_compare, class = typename _Mycomp::is_transparent> size_type count(const _Other& _Keyval) const { _Keyval _Paircc _Ans = equal_range(_Keyval); return (_STD distance(_Ans.first, _Ans.second)); } Best regards /Viktor Sehr

4 4

Interest in (parts of) type_safe, e.g. Boost.StrongTypedef?
by Jonathan Müller 15 Jun '18

15 Jun '18

I've been working on https://github.com/foonathan/type_safe for the past 20 months or so. What started as an experimenting ground for type safe programming facilities quickly turned into a general mix bag of utilities. However, it became my most popular project, so there is something in there people find really useful. And with that multiple approached me wanting to have it added to Boost, so here I am. I do realize that not all of it is suited for Boost: some of it has overlap with existing libraries (e.g. optional/variant), some of it has better implementations elsewhere (e.g. improved integer types) and some of it is to novel/experimental (e.g. stuff like constrained_type). But there are some things that could be useful for Boost. I'm mainly thinking of the strong typedef facility. I plan on splitting the library up into multiple parts anyway (see also https://github.com/foonathan/type_safe/issues/82) so please let me know whether there is anything you'd like to see being prepared for Boost. Thanks, Jonathan

3 2

[rational] release (optimized) builds are failing unit tests
by James E. King, III 12 Jun '18

12 Jun '18

I am adding CI to Boost.Rational and the unit tests are failing for different levels of optimization on different compilers. Before I dig into it further, does anybody have any idea what this might be? https://github.com/boostorg/rational/issues/18 See issue for error output. Ubuntu Bionic gcc unit test succeeds: -O0, -O1 unit test fails: -O2, -O3 boost@17b66a9efac4:/boost/libs/rational/test$ g++ --version g++ (Ubuntu 7.3.0-16ubuntu3) 7.3.0clang unit test succeeds: -O0 unit test fails: -O1, -O2, -O3 boost@17b66a9efac4:/boost/libs/rational/test$ clang++-6.0 --version clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final) Target: x86_64-pc-linux-gnu Thread model: posix InstalledDir: /usr/bin To reproduce, try: boost@17b66a9efac4:/boost/libs/rational/test$ ../../../b2 toolset=clang variant=release rational_test I am using the ubuntu bionic docker container to do the build in. See boostorg/boost#184 <https://github.com/boostorg/boost/pull/184>

1 0

[release] 1.68.0 deadline for new libraries approaching
by Marshall Clow 12 Jun '18

12 Jun '18

One week from tomorrow master will closed for new libraries. Upcoming dates: * 20-Jun: Boost 1.68.0 closed for new libraries and breaking changes * 27-Jun: Boost 1.68.0 closed for major code changes * 4-Jul: Boost 1.68.0 closed for beta * 11-Jul: Boost 1.68.0 beta 1 * 1-Aug: Boost 1.68.0 closed for release * 4-Aug: Boost 1.68.0 release -- The Boost Release Team

1 0

meta/libraries.json question
by Antony Polukhin 11 Jun '18

11 Jun '18

Hello, I see that I can specify "std": [ "proposal" ], in meta/libraries.json. What are the other options? Can I write "с++17" instead of "proposal" (for Any and Variant)? -- Best regards, Antony Polukhin

1 0

boost::winapi and Windows CE 7 and Windows Mobile 6
by Vyacheslav Lanovets 07 Jun '18

07 Jun '18

Hello, I am having big trouble migrating from 1.65.1 to 1.67 in VS2008 for CE platform. We already have quite a few patches for boost we reapply on every update. Boost 1.67 added more issues here and there, and among them the winapi library. On our old CE 7.00 I have winnt.h file where the second branch get selected. #if (defined(_M_MRX000) || defined(_M_IX86) || defined(_M_ALPHA) || defined(_M_PPC) || defined(_M_IA64)) && !defined(MIDL_PASS) #define DECLSPEC_IMPORT __declspec(dllimport) #else #define DECLSPEC_IMPORT #endif Therefore, WINAPI functions are not imported but is linked via corelib.lib library. So when I compile my code I see 3>D:\Dev\boost167\boost/winapi/semaphore.hpp(48) : error C2375: 'CreateSemaphoreW' : redefinition; different linkage 3> C:\Program Files (x86)\Windows CE Tools\SDKs\DS-200i\include\ARMv4I\winbase.h(3189) : see declaration of 'CreateSemaphoreW' To make things worse in Windows Mobile 6 SDK half of API is imported and half is not (goes through corelib.lib). Visual Studio 2008 installer includes WM6 SDK. And in the file C:\Program Files (x86)\Windows Mobile 6 SDK\PocketPC\include\ARMV4I\winbase.h there are functions not prefixed with WINBASEAPI. The solution would be to have 2 new defines instead of BOOST_SYMBOL_IMPORT in boost::winapi. On CE 7 both would be empty, on WM 6 one would be __declspec(dllimport) Regards, Vyacheslav

4 3

Yap formally accepted into Boost
by Louis Dionne 04 Jun '18

04 Jun '18

Dear Boost, This message is to announce that Yap (which had been conditionally accepted [1]) is now accepted into Boost, since the conditions for acceptance have been met. The conditions for acceptance were: - Improve the documentation to satisfy Brook Milligan and myself (done) - A single macro for symmetric binary operators (done in https://github.com/tzlaine/yap/issues/22) - Get rid of external dependencies checked into repository (done) - Boost.Build (done in https://github.com/tzlaine/yap/issues/52) Congratulations Zach! Louis Dionne Review manager for Boost.Yap [1]: https://lists.boost.org/boost-announce/2018/03/0540.php

2 1

Re: [boost] [Algorithm] contains(v, 1)
by Jean-Philippe DUFRAIGNE 04 Jun '18

04 Jun '18

On 5/31/18 3:14 AM, Olaf van der Spek via Boost wrote: > Hi, > > vector<int> v; > contains(v, 1); > > This doesn't work as contains expects two ranges (AFAIK). > Is there some other function that's usable for this purpose? > Should contains support a value for argument 2? > > Gr, > Hi, This algorithm exists: boost::any_of_equal https://www.boost.org/doc/libs/1_67_0/libs/algorithm/doc/html/the_boost_alg… Thanks; Jean-Philippe

2 1

[outcome] v2.1 progress report
by Niall Douglas 04 Jun '18

04 Jun '18

Dear Boost, Two months after you accepted Outcome into Boost, I am pleased to say that I believe that all the known bugs and very substantial source refactoring recommended by the peer review have been implemented (detailed changelog is appended below). What remains is a few months of maturing in real world use as all this severe refactoring needs to be tested outside a test suite, and of course the documentation which I don't intend to start work on until the autumn. The Boost edition has, obviously, received a major upgrade and it is now 100% "Boost native" in that it uses Boost.System and Boost.Exception now. The test suite for the Boost edition exclusively tests the Boost native edition, and it all passes. Outcome (both standalone and Boost editions) now can handle both Boost and std types freely intermixed as you see fit. A new "lite" single header edition exists which drags in virtually no system headers, and is hideously low impact on compile times as a result. ABI and API stability have been dumped to git repo with scripting to check the current library against the frozen dumps. This edition should make the corporate crowd very pleased. Very little should appear to have changed from the outside. Code written for v2.0 ought to, more or less, compile and work as before with v2.1. I would appreciate whatever help the Boost community can give in helping to test this edition. I expect new bugs to have been introduced given the severe source code refactoring, and new dual support for Boost and std as equals. My gratitude in advance. Niall --- ## v2.1 in progress [[project]](https://github.com/ned14/outcome/projects/1) - Boost edition is now 100% Boost, so defaults for `result` and `outcome` are `boost::system::error_code::errc_t` and `boost::exception_ptr`. Moreover, the test suite in the Boost edition now exclusively tests the Boost edition. One can, of course, freely use the standalone edition with Boost, and the Boost edition with `std` types. - Renamed ADL discovered customisation point `throw_as_system_error_with_payload()` to `outcome_throw_as_system_error_with_payload()`. - [#135](https://github.com/ned14/outcome/issues/135) - Added much clearer compile failure when user tries `result<T, T>` or `outcome` where two or more types are identical. Thanks to Andrzej Krzemieński for suggesting a technique which combines SFINAE correctness with the remaining ability for `result<T, T>` etc to be a valid type, but not constructible. - [#67](https://github.com/ned14/outcome/issues/67) - Fixed one of the oldest long open bugs in Outcome, that the noexcept unit tests failed on OS X for an unknown reason. - [#115](https://github.com/ned14/outcome/issues/115) - Outcome did not construct correctly from `failure_type`. - Inexplicably outcome's error + exception constructor had been removed. Nobody noticed during the Boost peer review, which is worrying seeing as that constructor is needed for one of the main advertised features to Boost! - [#107](https://github.com/ned14/outcome/issues/107) and [#116](https://github.com/ned14/outcome/issues/116) - `operator==` and `operator!=` now become disabled if the value, error and exception types do not implement the same operator. - Relatedly, both comparison operators simply didn't work right. Fixed. - [#109](https://github.com/ned14/outcome/issues/109) - `swap()` now has correct `noexcept` calculation and now correctly orders the swaps to be whichever is the throwing swap first. - Added reference dump of v2.1 ABI so we can check if ABI breakage detection works in the next set of changes, plus Travis job to check ABI and API compatibility per commit. - [#124](https://github.com/ned14/outcome/issues/124) - `OUTCOME_TRY` is now overloaded and selects `void` or `auto` edition according to input parameter count. - [#120](https://github.com/ned14/outcome/issues/120) - Fix generation of double underscored temporary variables in `OUTCOME_UNIQUE_NAME`, which is UB. - [#110](https://github.com/ned14/outcome/issues/110) - Separated `result` from its hard coded dependency on the `<system_error>` header. - Renamed `result` and `outcome` to `basic_result` and `basic_outcome`. - Renamed `result.hpp` into `basic_result.hpp`. - Moved `<system_error>` and `<exception>` dependent code into new `std_result.hpp` and `std_outcome.hpp` header files. - Added `boost_result.hpp` and `boost_outcome.hpp` which use Boost.System and Boost.Exception (these are `result.hpp` and `outcome.hpp` in the Boost edition). -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

1 1

[beast] How do I select un-DEPRECATED interfaces?
by Brian Kuhl 04 Jun '18

04 Jun '18

Hi Experts, I’m working with an EAR release of VxWorks 7 with llvm v5.0 and VxWorks’ first C++14 STL ( Dinkum v700) and Boost v 1.67 ( Yes, the RTOS world moves slowly) I’ve gotten a clean compile of Beast with #define BOOST_BEAST_ALLOW_DEPRECATED #define BOOST_COROUTINES_NO_DEPRECATION_WARNING But I’m having trouble locating the logic that’s choosing these deprecated interfaces for me? Could someone point out the relevant logic? Many Thanks, Brian Kuhl Senior Manager – Information Development Wind River

2 1

[Algorithm] contains(v, 1)
by Olaf van der Spek 03 Jun '18

03 Jun '18

Hi, vector<int> v; contains(v, 1); This doesn't work as contains expects two ranges (AFAIK). Is there some other function that's usable for this purpose? Should contains support a value for argument 2? Gr, -- Olaf

5 13

[compressed_pair] [hof] [hana] What's the story with compressed_pair?
by Tom Westerhout 30 May '18

30 May '18

Hello! It looks like there are at least three different implementations of a "std::pair with EBO" in Boost: boost/utility/compressed_pair.hpp boost/hof/detail/compressed_pair.hpp boost/hana/pair.hpp Finally, there is also std::tuple which seems to also make use of EBO. I need similar functionality for a GSoC project I'm working on this year. So I'm wondering, is compressed pair considered a simple technicality that should be implemented from scratch every time I need it or shall I stick to one of the four mentioned implementations? I would much prefer to use Boost.Utility's one, but unfortunately it's neither constexpr-friendly nor noexcept-friendly... Is there some reason why it cannot be annotated with macros which expand to constexpr and noexcept when compiled with C++11 support? Or has no one just gotten around to do it? Thanks in advance, Tom

3 3

[Hana] "basic_tuple.hpp" bug when building with VS2017
by Louis Dionne 30 May '18

30 May '18

> Hello, > > Just installed Boost and Visual Studio 2017 a few days ago. Visual Studio 2017 is known to be unable to compile Hana (and other libraries such as Range-v3). I will be working with the Microsoft folks to make it work as they explicitly reached out to me with that intent. Cheers, Louis

4 9

[testing][regressions] All my regressions testers failing due to connection errors to GitHub
by Ion Gaztañaga 28 May '18

28 May '18

Hi, All my 4 testers (I have 4 machines running several Mingw targets) are always failing pulling new versions from GitHub. This problem started some days ago. I've tried to reset all machines, network equipment, disabling antivirus, firewall, modified http attributes, modified the regression script to use git protocol instead of https, etc. with no luck. I'm using Windows machines with official Git. Any clue on what's going on? Maybe Github recently does not like so many submodules? Example of failure (several libraries can fail during "git pull "--recurse-submodules""): ------------------- ------------------- ------------------- Fetching submodule libs/io fatal: unable to access 'https://github.com/boostorg/io.git/': OpenSSL SSL_read: SSL_ERROR_SYSCALL, errno 10054 Then: # git_source_checkout failed with message "GIT command "git pull "--recurse-submodules"" failed with code 1" # Retrying (5 more attempts). # Executing GIT command: c:\boost\develop\boost_root> git submodule foreach "git submodule deinit ." ------------------- ------------------- All retries fail and the script fails with error: ------------------- ------------------- ------------------- # git_source_checkout failed with message "GIT command "git pull "--recurse-submodules"" failed with code 1" # Giving up. Traceback (most recent call last): File "run.py", line 71, in <module> runner(root) File "c:\boost\develop\boost_regression_src\regression.py", line 286, in __init__ self.main() File "c:\boost\develop\boost_regression_src\regression.py", line 623, in main getattr(self,action_m)() File "c:\boost\develop\boost_regression_src\regression.py", line 578, in command_regression self.command_get_source() File "c:\boost\develop\boost_regression_src\regression.py", line 330, in command_get_source self.retry(self.git_source_checkout) File "c:\boost\develop\boost_regression_src\regression.py", line 662, in retry return f() File "c:\boost\develop\boost_regression_src\regression.py", line 875, in git_source_checkout self.git_checkout(git_info['boost'], self.git_branch(), clean) File "c:\boost\develop\boost_regression_src\regression.py", line 849, in git_checkout self.git_command( 'pull', '--recurse-submodules' ) File "c:\boost\develop\boost_regression_src\regression.py", line 834, in git_command raise Exception( 'GIT command "%s" failed with code %d' % (git_cli, rc) ) Exception: GIT command "git pull "--recurse-submodules"" failed with code 1 END 24/05/2018 15:28:37,46 ------------------- ------------------- ------------------- Errors are never in the same libraries, very few times the checkout succeeds and a regression is run. Anyone else having these problems? I've attached the log of one failure in case someone can see any clue. I really don't see how to solve this, so I won't be able to run regressions. Best, Ion

3 4

GCC versions
by Ian Emmons 28 May '18

28 May '18

Apologies if this is off topic, but the audience here is perfect for this question: I need to support CentOS version 7 with my C++ software. The version of GCC that is supported out-of-the-box on that version of Linux is rather old -- it supports C++11, but not C++14, and of course I would like to use a newer standard. Is it common practice on Linux to install a later version of GCC than the out-of-the-box on version? If so, how do you handle the run-time shared library dependencies? Any pointers would be helpful. Thanks, Ian

3 2

Boost multiprecision differential fuzzer running on Google's oss-fuzz
by Guido Vranken 28 May '18

28 May '18

Dear list, I built a bignum differential fuzzer [1] that has been running on Google's oss-fuzz service [2] for a while. It performs the same mathematical operations (addition, subtraction, multiplication, modular exponentation, etc) across multiple bignum libraries (eg. OpenSSL + Boost multiprecision), compares their results and crashes if they don't match. This effort has so far found a couple of (minor) bugs in OpenSSL and Go. As soon as a mismatch is found, oss-fuzz will send a notification e-mail to the developers of the various bignum libraries so the bug can be examined and resolved. At which e-mail address(es) do the developers of Boost wish to receive these notifications? Please bear in mind that the notifications will contain potentially security-sensitive information so the recipient may not be a public mailing list. Currently, a potential bug is found only every couple of weeks, so recipients do not have to worry about a lot of incoming traffic. If you wish to write comments to the fuzzer's private bug tracker, the e-mail you specify must be linked to a Google account. To all others who are reading this, please feel welcome to submit pull requests to the Boost multiprecision module of my fuzzer [3] if these modifications increase the scope (code coverage) and probability of finding bugs. Thanks, Guido [1] https://github.com/guidovranken/bignum-fuzzer [2] https://github.com/google/oss-fuzz [3] https://github.com/guidovranken/bignum-fuzzer/tree/master/modules/cpp_boost

2 1

[windows] Wni32/Vigorf.A trojan in boost_1_67_0-msvc-14.1-64.exe?
by Mateusz Loskot 28 May '18

28 May '18

Hi, One user reported via #boost at cpplang.slack.com that Windows Defender reported trojan in the latest Windows binaries. I checked myself and I can confirm the latest up-to-date Windows Defender is detecting Vigorf.A in the installer archive. Is this false report? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

5 7

Boost.DisjointSets and Boost.Container
by James E. King, III 27 May '18

27 May '18

Currently the disjoint_sets repository ( https://github.com/boostorg/disjoint_sets) holds a single class in "boost/pending" that is only used by the graph and graph_parallel projects (that I can tell...). I'd like us to consider taking disjoint_sets out of pending state and make it official as part of Boost Containers. Both Graph and GraphParallel require linking already, and they may already use Boost.Containers (I haven't checked). disjoint_sets is header-only however and this might cause problems for anyone relying on it, however since it's in boost/pending, I wonder if anyone is actually using it. Given the pending designation on it however, a breaking change seems reasonable to me. It will reduce the burden on the CMT, and container has at least some CI on it already. Thoughts? - Jim

1 0

[SPAM]
by Scott Karns 25 May '18

25 May '18

http://follow.anthologypaper.com Scott Karns

1 0

Interest in a tiny kmeans library
by Raffi Enficiaud 23 May '18

23 May '18

Dear all, We are finishing the cleanup of a tiny kmeans library. For those who do not know, kmeans is a widely used data clustering algorithm. This special implementation has a lower runtime complexity by taking advantages of the triangle inequalities between clusters and data points at each iteration. This implementation is based on the paper of Charles Elkan https://www.aaai.org/Papers/ICML/2003/ICML03-022.pdf We have also python and matlab bindings, fully generic on the data type, and with additional initialization heuristics. I would be happy if we can release this library into Boost. Do you think there is any interest for the community? Best regards, Jean-Claude Passy and Raffi Enficiaud

5 5

PR: Remove safe_bool idiom from boost.tribool
by Robert Ramey 22 May '18

22 May '18

Removed usage of "safe_bool" idiom from tribool. This was initially motivated by the fact that usage of this idiom with all current and past gcc compilers with constexpr does not work. First it reports reference to the address of a local member function as not being constexpr. This may or may not be correct according to the standard. FWIW clang is OK with it. Making the member function constexpr fixes this error. But still there is a problem. in GCC, the operator to implicitly covert the instance to a void * does not seem to work. Invocation of this operator in the context of an argument to an if(... or other conditional doesn't result in behavior similar to bool. Not even a static cast to a bool seems to work. Again CLANG is OK with all this. This has been reported as an issue to the GCC team. One idea which has been tried is to use C++11 "explicit" as a substitute from the safe_bool idiom. Unfortunately this breaks legacy code. bool f(x) { return tribool(true); // fails } So this is not a great solution either. Attempts to resolve this were inconclusive. This motivated me to think about why the safe_bool idiom was being used here at all. According to articles on safe_bool articles this main reason is to support the common practice of using a not null value in a conditional: Testable t; if(t) ... without accidentally permitting things like if(t >> 1)... The above would occur if Testable included an operator bool () const member function. Basically safe_bool is meant to support the common C/C++ practice of implicity converting something to bool so we write something like if(t) ... to mean t "is_valid" or "is_not_null" or some such. a) I don't think this idiom is a good idea and even more so in the context of modern C++. Conversion of a Testable instance to a bool instance should result in something that looks/acts like a C bool - not something else like a void * which C then maps to a bool. If we want to use a bool for something like "is_valid" we'd be much better off just implementing is_valid directly. There would be then no confusion, side effects or hand a waving. b) it's an especially a bad idea for tribool. The motivating concept behind tribool is that of some sort of "extended" bool. The naming suggests that it acts like a bool. But since we've used he safe_bool idiom, it doesn't any more. That is we can't use a tribool anywhere a bool is used. So if we use operator bool we'll get a tribool which acts like a bool - even when the original usage of bool was a bad idea according to a) above. But at least we have the same behavior for tribool and bool which is a lot more intuitive and less confusing. Also, changing to operator bool () will address the current problem with GCC not supporting a constexpr version of tribool. Accordingly, I've submitted this PR to change the implementation of tribool to avoid the safe_bool idiom.

7 22

FWD: [cfe-users] Boost.GIL test failing with clang 5.x while pass with 15 gcc/clang versions
by Mateusz Loskot 21 May '18

21 May '18

Hi, I posted this to clang mailing list a http://lists.llvm.org/pipermail/cfe-users/2018-May/001335.html but since it is related to Boost.GIL bugs I'm investigating, I'd like to reach for feedback here too. I'll appreciate any comments regarding the issue explained below. ML ---------- Forwarded message ---------- From: Mateusz Loskot <mateusz(a)loskot.net> Date: 19 May 2018 at 21:38 Subject: Boost.GIL test failing with clang 5.x while pass with 15 gcc/clang versions To: cfe-users(a)lists.llvm.org Hi, While testing Boost.GIL library [1] with gcc and clang, I noticed a peculiar issue. One particular test is failing with lang 5.x while passing with total of 15-17 other versions of clang and GCC (total workflow of CircleCI with at [2]). Below is extracted minimal program equivalent to Boost.GIL channel_invert algorithm. It includes two variants: plain expression and the same expression wrapped with a function template: #include <limits> #include <iostream> #include <typeinfo> template <typename C> inline C channel_invert1(C x) { return std::numeric_limits<C>::max() - x + std::numeric_limits<C>::min(); } template <typename C> inline C channel_invert2(C x) { return (x - std::numeric_limits<C>::max()) * (-1) + std::numeric_limits<C>::min(); } int main() { int x = std::numeric_limits<int>::min(); std::cout << x << std::endl; // plain expressions int x_invert1 = std::numeric_limits<int>::max() - x + std::numeric_limits<int>::min(); int x_invert2 = (x - std::numeric_limits<int>::max()) * (-1) + std::numeric_limits<int>::min(); std::cout << x_invert1 << std::endl; std::cout << x_invert2 << std::endl; // the same expressions wrapped in function template std::cout << channel_invert1<int>(x) << std::endl; std::cout << channel_invert2<int>(x) << std::endl; } If compiled as optimised variant (-O2 or -O3) with clang 5.x outputs the following: -2147483648 2147483647 2147483647 -1 -1 The last two negative one is not expected. If compiled with clang 3.9, 4.0 or gcc from 5.1 to 7.3 it outputs -2147483648 2147483647 2147483647 2147483647 2147483647 Could anyone help me to understand what is going on in the clang 5 case? Or, what UB is this hitting? [1] https://github.com/boostorg/gil/issues/89 [2] https://circleci.com/workflow-run/3a14dd64-6c38-46b2-a6da-678c0075ca27 Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

1 1

Enabling issues on boostorg/mpi
by Alain Miniussi 21 May '18

21 May '18

Hi, Could somebody with the sufficient permissions enable issues on the github mpi repository ? Thanks Alain Miniussi

2 2

Proposal for a thread synchronisation primitive: future_queue
by Martin Hierholzer 21 May '18

21 May '18

Dear boost developers, I want to propose a thread synchronisation primitive, which works like a mixture of (lockfree) queues and futures. Therefore I gave it the name "future_queue". It is basically a lockfree queue which can be waited on for new values (without busy waiting), but it has some nice extra features like when_any() and continuations. The github project can be found here: https://github.com/mhier/future_queue It already contains a README file with a short description, an example and results of a first performance measurement. Further documentation so far exists only inside the code: https://github.com/mhier/future_queue/blob/master/include/future_queue.hpp My first question is, whether this is really something new (I might have overlooked something in the many boost libraries) and if it makes sense to integrate it into the boost libraries. Another question would be whether this should really be its own library, since it is basically a single class (with a few helper classes) and a single non-member function. Maybe it would be better to make it part of an existing library? I am happy to receive some first feedback! Cheers, Martin -- Martin Hierholzer DESY Notkestrasse 85 22607 Hamburg Office 55a / 123 Tel: +49 40 8998 1897 Mob: +49 176 992 46 476 Skype: mhier48 This e-mail may contain confidential and/or privileged information and is intended only for the use of the individual or entity named above. If you received it in error, please advise the sender immediately by reply e-mail and delete the original. Any further use - especially any form of publication - of this e-mail without explicit authorisation is strictly prohibited.

4 11

[Hana] "basic_tuple.hpp" bug when building with VS2017
by Daniel Chen 20 May '18

20 May '18

Hello, Just installed Boost and Visual Studio 2017 a few days ago. Here is a bug when building with Hana's "basic_tuple.hpp" header with Visual Studio 2017: In basic_tuple.hpp: template <> struct drop_front_impl<basic_tuple_tag> { template <std::size_t N, typename Xs, std::size_t ...i> static constexpr auto drop_front_helper(Xs&& xs, std::index_sequence<i...>) { return hana::make_basic_tuple( detail::ebo_get<detail::bti<i+N>>(static_cast<Xs&&>(xs))... ); } template <typename Xs, typename N> static constexpr auto apply(Xs&& xs, N const&) { constexpr std::size_t len = detail::decay<Xs>::type::size_; return drop_front_helper<N::value>(static_cast<Xs&&>(xs), std::make_index_sequence< N::value < len ? len - N::value : 0 >{}); //<Bug here - line 197 of basic_tuple.hpp } }; Upon building with "basic_tuple.hpp", the line highlighted in green reports an error: "syntax error: unexpected token ')', expected 'id-expression'". Focus on the line above that one: N::value < len ? len - N::value : 0 If you add parentheses, the error goes away: (N::value < len) ? len - N::value : 0 A similar bug occurs - and is fixed likewise - in the "string.hpp" header file at line 275, that is: template <> struct drop_front_impl<string_tag> { ... template <char ...xs, typename N> static constexpr auto apply(string<xs...> const& s, N const&) { return helper<N::value>(s, std::make_index_sequence< N::value < sizeof...(xs) ? sizeof...(xs) - N::value : 0 >{}); //<bug here - line 275 of string.hpp } I'm not sure if this is a Microsoft compiler issue (I will post to them as well), but I feel like someone should add those parentheses (and then some) to the line since it is safer - the "<" can be easily confused for a template bracket instead of a less-than sign by a parser. Daniel Chen Infinera

2 1

Boost.Test, cygwin, and ISO/POSIX
by James E. King, III 19 May '18

19 May '18

Hello, I have been adding some CI infrastructure to the CMT repositories and found I am able to reproduce a failure building boost libraries that use Boost.Test for their unit tests. If you build with "cxxstd=03" you can get to some undefined functions. See: https://github.com/boostorg/test/issues/144 It looks like one needs to define _POSIX_C_SOURCE=200112L or cxxstd-dialect=gnu in order for these functions to become visible. I was thinking of addressing this two ways: 1. I want to change boost build (bjam) to define _POSIX_C_SOURCE when building on cygwin to this value if it is not otherwise defined. I can't find the right place to add this. 2. I don't think it's reasonable for Boost.Test to modify _POSIX_C_SOURCE since it could be included after sys/functional header, so I would like to either change Boost.Test so it does not depend on these three functions, or check to see if the right preprocessor definitions are set on cygwin and put up a better error message, or simply change the documentation and update all the CI build scripts in all the affected repositories to set _POSIX_C_SOURCE as part of the CI build. Any thoughts or other ideas on this? Thanks, Jim

1 0

disjoint_sets repo status
by James E. King, III 17 May '18

17 May '18

What is the current status of https://github.com/boostorg/disjoint_sets ? The headers appear to be in a "pending" state. There's almost nothing in this repo. Perhaps it was put here to solve a circular dependency issue? It looks like it is used by graph and graph_parallel. Could we move this into Boost.Algorithm? Thanks, Jim

1 0

[release][chrono] libs/chrono/stopwatches/include not in boost/chrono/stopwatches
by Andrey Semashev 17 May '18

17 May '18

Hi, In the 1.67 released archive, there is libs/chrono/stopwatches/include directory that contains headers that look like they should be placed in boost/chrono/stopwatches. With the checkout from git, `b2 headers` create links boost/chrono/stopwatches and boost/chrono/stopwatches.hpp that refer to that directory. Looks like the packaging scripts need to be updated.

2 1

dynamic_bitset needs some attention
by James E. King, III 16 May '18

16 May '18

I have been adding a common CI infrastructure to the CMT repositories. Occasionally I have to disable one or two build jobs to get a clean build and I file an issue. When I got to dynamic_bitset however, there's clearly something going on in there and it isn't good. I think it has to do with streaming. It's probably just one issue causing most of the failures. You can see the results from my latest dry-run PR here: https://github.com/jeking3/dynamic_bitset/pull/1 Right now both the main travis and all of the appveyor builds are failing, and they all look like they get stuck on test 4 in iostream processing. Something just isn't right in there - it could be the test itself or it could be something else. I may submit a PR into the repo for the CI additions anyway even if they are failing, since it points out this component has rotted and needs attention. Also if my PRs in pool and function can be merged, we'll have better CI on those. Aiming to get all the CMT repos covered with appveyor, travis, codecov, and eventually covscan. - Jim

1 0

Clarifying Boost evolution plans mentioned on Twitter
by Bryce Adelstein Lelbach aka wash 16 May '18

16 May '18

Hi all, Some pictures from the C++Now "Boost Library In A Week" end-of-week summary were posted to Twitter today by an attendee, along with some mistaken statements suggesting that "Boost plans to move to C++11". I want to clarify what is actually going on: 0.) During the week, the Library In A Week group discussed some ideas for how Boost might migrate to newer standards. I'm somewhat to blame as I initiated these discussions. 1.) Those ideas were collected into a draft document by Jeff Garland. 2.) During the closing panel, Jeff presented the draft document and stated the next step would be to share it with the mailing list. 3.) Due to an innocent misunderstanding, an attendee posted a picture of part of the document with the unclear message "Boost plans to move to C++11". 4.) I wrote this email. I have asked the attendee to delete the tweet (and repost with a clearer message if they wish). I don't want to share the document from LIAW. Jeff put a lot of work into it and I don't want to steal his thunder (I realize this email inevitably does that). I'm sure he will follow up with a post explaining what ideas we came up with soon. I'm very sorry for the confusion, and I'm sure the attendee is as well. This was just an innocent mixup. ------------------------------------------------------ Bryce Adelstein Lelbach aka wash ISO C++ Committee Member CppCon and C++Now Program Chair Thrust Maintainer, HPX Developer CUDA Convert and Reformed AVX Junkie Sleep is for the weak ------------------------------------------------------

4 3

[interprocess]Request to support wchar_t* file name on Windows
by 孙朝阳 15 May '18

15 May '18

Hi, I'm using boost.interprocess.file_mapping on Windows, and I need to use it to open files with localized file path, so I want file_mapping can support wchar_t file name on Windows. Does any reason prevent file_mapping to support wchar_t file name? If no, would someone like to add wchar_t supporting for file_mapping? I also created a pull request for this: https://github.com/boostorg/interprocess/pull/28 Thanks, Jackson Sun

1 0

boost libs compiled for gcc toolset with boost 1.67 and CMake 3.11 won't find libs
by Demetri Kopsas 12 May '18

12 May '18

Hi, I discovered that the latest version of boost does not work with CMake when using the GCC toolset. I submitted this bug: https://gitlab.kitware.com/cmake/cmake/issues/17974#note_408614 Using MSVC as the toolset is fine on windows, but using mingw (gcc compiler) cannot find the libs unless I take out ‘x32’ or ‘x64’ from the name after compilation.

2 1

[build] recent issues w. VS 2017
by Raffi Enficiaud 12 May '18

12 May '18

Dear all, I am experiencing an issue with VS 2017 (15.6.6) while compiling boost.test on my agent. Traces below. I do not recall having applied any change to this agent apart from installing C++/CLI support for CMake people. Is this problem known? Thanks, Raffi build 01-May-2018 11:43:49 D:\bamboo_build_dir\SW-BCB161-VC2017WIN\library\libs\test\test>..\..\..\b2 --abbreviate-paths toolset=msvc-14.1 cxxflags="/std:c++latest" build 01-May-2018 11:43:50 Performing configuration checks build 01-May-2018 11:43:50 build 01-May-2018 11:43:50 - default address-model : 32-bit (cached) build 01-May-2018 11:43:50 - default architecture : x86 (cached) build 01-May-2018 11:43:50 - symlinks supported : no (cached) build 01-May-2018 11:43:50 - junctions supported : yes (cached) build 01-May-2018 11:43:50 - hardlinks supported : yes (cached) build 01-May-2018 11:43:51 - BOOST_COMP_GNUC >= 4.3.0 : no build 01-May-2018 11:43:54 - Boost.Config Feature Check: cxx11_auto_declarations : no build 01-May-2018 11:43:54 - Boost.Config Feature Check: cxx11_function_template_default_args : no build 01-May-2018 11:43:54 - Boost.Config Feature Check: cxx11_lambdas : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_hdr_initializer_list : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_template_aliases : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_decltype : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_hdr_random : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_hdr_tuple : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_variadic_macros : no build 01-May-2018 11:43:55 - Boost.Config Feature Check: cxx11_trailing_result_types : no build 01-May-2018 11:43:56 - Boost.Config Feature Check: cxx11_nullptr : no build 01-May-2018 11:43:56 - Boost.Config Feature Check: cxx11_unified_initialization_syntax : no build 01-May-2018 11:43:56 - Boost.Config Feature Check: cxx11_variadic_templates : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_decltype : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_hdr_random : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_hdr_tuple : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_hdr_initializer_list : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_variadic_macros : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_trailing_result_types : no build 01-May-2018 11:43:57 - Boost.Config Feature Check: cxx11_template_aliases : no build 01-May-2018 11:43:57 ...patience... build 01-May-2018 11:43:57 ...found 3946 targets... build 01-May-2018 11:43:57 ...updating 553 targets... build 01-May-2018 11:43:58 compile-c-c++ ..\..\..\bin.v2\libs\test\test\string_cast-test.test\msvc-14.1\dbg\thrd-mlt\utils-ts\string_cast-test.obj build 01-May-2018 11:43:58 string_cast-test.cpp build 01-May-2018 11:43:58 D:\bamboo_build_dir\SW-BCB161-VC2017WIN\library\boost/config/detail/select_stdlib_config.hpp(18): fatal error C1083: Cannot open include file: 'cstddef': No such file or directory build 01-May-2018 11:43:58 build 01-May-2018 11:43:58 call "..\..\..\bin.v2\standalone\msvc\msvc-14.1\msvc-setup.bat" >nul build 01-May-2018 11:43:58 cl /Zm800 -nologo @"..\..\..\bin.v2\libs\test\test\string_cast-test.test\msvc-14.1\dbg\thrd-mlt\utils-ts\string_cast-test.obj.rsp" build 01-May-2018 11:43:58 build 01-May-2018 11:43:58 ...failed compile-c-c++ ..\..\..\bin.v2\libs\test\test\string_cast-test.test\msvc-14.1\dbg\thrd-mlt\utils-ts\string_cast-test.obj... build 01-May-2018 11:43:58 compile-c-c++ ..\..\..\bin.v2\libs\test\build\msvc-14.1\dbg\lnk-sttc\thrd-mlt\compiler_log_formatter.obj

3 5

new b2 property or new boost library?
by Oliver Kowalke 11 May '18

11 May '18

Hi, boost.fiber provides some rudimentary NUMA support. NUMA specific OS APIs require the native thread handle (native_handle_type std::thread::native_handle()). But unfortunately the returned type does not match in all cases the OS handle type. For instance MinGW-W64 using the POSIX thread impl returns long long instead of void*. A solution would be to add an additional b2 property like `numa=on` that compiles the NUMA related part of boost.fiber if set (the user is responsible to compile boost with the appropriate properties). Or the NUMA related code is move from boost.fiber into a complete new boost library. What would be you advice? Oliver

1 0

[type_traits] revisiting is_virtual_base_of
by John Maddock 10 May '18

10 May '18

There is a problem with is_virtual_base_of in that it doesn't work especially well - most of the time it works OK, but can be made to fail catastrophically in a few situations, see for example: https://svn.boost.org/trac10/ticket/11323 Now... it turns out that with C++14 and later we now have is_detected which can test the validity of almost any expression... and I'm wondering if there's a cunning way to press this into action to create a more accurate is_virtual_base_of, but I'm having trouble coming up with anything. Any bright ideas? Note that an explicit static_cast can't be tested for, though we can use is_constructible if required. Thanks in advance, John. --- This email has been checked for viruses by AVG. http://www.avg.com

2 3

build failure in develop: chrono, type_traits?
by James E. King, III 08 May '18

08 May '18

The only change in my pull request was to remove a deprecated, unrelated header in uuid. This happened in the builds last night on develop: In file included from ./boost/config.hpp:61:0, from ./boost/chrono/config.hpp:15, from ./boost/chrono/detail/inlined/process_cpu_clocks.hpp:15, from libs\chrono\src\process_cpu_clocks.cpp:17: ./boost/type_traits/detail/common_arithmetic_type.hpp:209:27: error: duplicate 'const' BOOST_STATIC_CONSTANT(const int, selector = sizeof(select(cond() ? T() : U()))); ^ "x86_64-w64-mingw32-g++.exe" -std=c++03 -m64 -O0 -fno-inline -Wall -pedantic -g -Wextra -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_STATIC_LINK=1 -I"." -c -o "bin.v2\libs\chrono\build\gcc-mingw64\debug\cxxstd-03-iso\link-static\process_cpu_clocks.o" "libs\chrono\src\process_cpu_clocks.cpp" ...failed gcc.compile.c++ bin.v2\libs\chrono\build\gcc-mingw64\debug\cxxstd-03-iso\link-static\process_cpu_clocks.o... Failed on cygwin and mingw builds: https://ci.appveyor.com/project/jeking3/uuid-gaamf/build/1.0.116-develop/jo… Also failed in c++03 builds on unix: https://travis-ci.org/boostorg/uuid/jobs/376161574#L2158 gcc.compile.c++ ../../bin.v2/libs/chrono/build/gcc-7/release/cxxstd-03-iso/link-static/thread_clock.o In file included from ../../boost/config.hpp:61:0, from ../../boost/chrono/config.hpp:15, from ../../boost/chrono/detail/inlined/thread_clock.hpp:14, from ../../libs/chrono/src/thread_clock.cpp:18: ../../boost/type_traits/detail/common_arithmetic_type.hpp:209:27: error: duplicate ‘const’ BOOST_STATIC_CONSTANT(const int, selector = sizeof(select(cond() ? T() : U()))); ^ "g++-7" -std=c++03 -m64 -O3 -finline-functions -Wno-inline -Wall -pedantic -Wextra -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"../.." -c -o "../../bin.v2/libs/chrono/build/gcc-7/release/cxxstd-03-iso/link-static/thread_clock.o" "../../libs/chrono/src/thread_clock.cpp" ...failed gcc.compile.c++ ../../bin.v2/libs/chrono/build/gcc-7/release/cxxstd-03-iso/link-static/thread_clock.o... Thanks, Jim

2 1

[filesystem] and C++17 std::filesystem
by Egor Pugin 07 May '18

07 May '18

Hi! gcc8.1 and VS15.7 (2017) are now shipped with std::filesystem. I'd like to raise a discussion about pure c++ interoperability with boost(::filesystem). With boost-1.67 it's not possible to do such things: #if __has_include(<filesystem>) #include <filesystem> namespace fs = std::filesystem; #else #include <boost/filesystem.hpp> namespace fs = boost::filesystem; #endif Because of boost::filesystem::copy_option::overwrite_if_exists != std::filesystem::copy_options::overwrite_existing, std::fs::path() / boost::fs::unique_path(), directory iterators etc. Next, if we take boost::process, for example, we see that it currently operates only on boost::filesystem. If my application uses c++17 fs, I have to write something like this: fs::path f(fs::path in) { bp::search_path(in.u8string()).wstring(); } So, mixing pure c++ and boost becomes more complex. Any ideas how to deal better with such issues on the user side? What are directions of proper fixing this in boost::process (in case I'll try to prepare a PR)? What are boost policies in adopting standard features in general? -- Egor Pugin

2 1

Boost Graph Library(biconnected_components) issue
by Meghana.M Reddy 06 May '18

06 May '18

Hi, I am working on the Boost Graph Library, currently trying to create an interface of the biconnected_components method to a Python code. I used the example code available here <https://www.boost.org/doc/libs/1_67_0/libs/graph/example/biconnected_compon…> for the method and modified it for my purpose. The template of the method is here <https://www.boost.org/doc/libs/1_67_0/libs/graph/doc/biconnected_components…>. The final code seems fine but I get an error while compiling it. And the errors are related to adjacency.hpp which I have not changed so I'm confused as to what the exact problem is. Hoping someone can help me out. My code: class BoostGraph { private: typedef typename boost::adjacency_list< OutEdgeListS, VertexListS, DirectedS, boost::property<boost::vertex_index_t, v_index>, EdgeProperty, boost::no_property, EdgeListS> adjacency_list; typedef typename boost::property_map<adjacency_list, boost::edge_index_t>::type components; public: adjacency_list graph; std::vector<v_index> bc_tree() { components components_bc = get(boost::edge_index, graph); std::size_t num_comps = biconnected_components(graph, components_bc); std::cerr << "Found " << num_comps << " biconnected components.\n"; std::vector<vertex_descriptor> art_points; articulation_points(graph, std::back_inserter(art_points)); std::cerr << "Found " << art_points.size() << " articulation points.\n"; std::vector<v_index> to_return; return to_return; } The error I'm getting: build/cythonized/sage/graphs/base/boost_graph.cpp:3730:26: required from here /home/meghana/Documents/sage_gsoc/sage_may/sage/local/include/boost/graph/detail/adjacency_list.hpp:2696:29: error: forming reference to void typedef value_type& reference; ^ /home/meghana/Documents/sage_gsoc/sage_may/sage/local/include/boost/graph/detail/adjacency_list.hpp:2697:35: error: forming reference to void typedef const value_type& const_reference; ^ /home/meghana/Documents/sage_gsoc/sage_may/sage/local/include/boost/graph/detail/adjacency_list.hpp:2701:61: error: forming reference to void typename Graph::vertex_descriptor,Property,Tag> type; ^ /home/meghana/Documents/sage_gsoc/sage_may/sage/local/include/boost/graph/detail/adjacency_list.hpp:2704:68: error: forming reference to void typename Graph::vertex_descriptor,const Property, Tag> const_type; ^ error: command 'gcc' failed with exit status 1 Makefile:33: recipe for target 'sage' failed make: *** [sage] Error 1 Thank you, Meghana

1 0

Fw: Mysterious Boost.System-related errors when running Beast tests
by Peter Dimov 05 May '18

05 May '18

The story starts with https://travis-ci.org/vinniefalco/beast/jobs/375049193 which gives the error dyld: Symbol not found: __ZN5boost6system6detail19system_category_ncxEv Referenced from: /Users/travis/build/vinniefalco/boost-root/bin.v2/libs/beast/test/beast/core/clang-darwin-4.2.1/debug/threadapi-pthread/threading-multi/fat-tests Expected in: /usr/local/lib/libboost_system.dylib boost::system::detail::system_category_ncx is a new function (in develop), and careful reading of the above reveals that the compiler is trying to link to a preinstalled libboost_system.dylib, in /usr/local/lib. Looking at the log, Boost.System is not even being built. This is odd; the Beast root Jamfile contains <library>/boost/system//boost_system (at https://github.com/boostorg/beast/blob/develop/Jamfile#L78) but even if it didn't, it also links to Filesystem, which _is_ being built, and Filesystem also depends on System in its build/Jamfile: https://github.com/boostorg/filesystem/blob/develop/build/Jamfile.v2#L29 So Boost.System should be built, but it isn't. Its Jamfile hasn't been touched in 10 years: https://github.com/boostorg/system/blob/develop/build/Jamfile.v2 In addition, there's not even a `mklink-or-dir boost/system` in the log, even though the link must be created because the new headers are being used (this could be a separate issue). The Linux/g++ job, https://travis-ci.org/vinniefalco/beast/jobs/375049187, also doesn't seem to build Boost.System, but it works for some reason. When I try `b2 libs/beast/test` on Windows, with msvc-14.1, Boost.System is being built, in the very beginning: ...patience... ...patience... ...patience... ...found 6992 targets... ...updating 1090 targets... link.hardlink ..\..\boost\utility\string_view.hpp Hardlink created for ..\..\boost\utility\string_view.hpp <<===>> ..\utility\include\boost\utility\string_view.hpp compile-c-c++ ..\..\bin.v2\libs\beast\test\beast\core\type_traits.test\msvc-14.1\debug\threadapi-win32\threading-multi\type_traits.obj type_traits.cpp compile-c-c++ ..\..\bin.v2\libs\beast\test\beast\core\type_traits.test\msvc-14.1\debug\threadapi-win32\threading-multi\main.obj main.cpp compile-c-c++ ..\..\bin.v2\libs\system\build\msvc-14.1\debug\threading-multi\error_code.obj error_code.cpp msvc.link.dll ..\..\bin.v2\libs\system\build\msvc-14.1\debug\threading-multi\boost_system-vc141-mt-gd-x32-1_66.dll (The 1.66 version instead of 1.68 was caused by a typo in the superproject which is now fixed.) When I try the same on Ubuntu Trusty, the result is the same as on Travis; no `mklink-or-dir boost/system`, no building of Boost.System, yet everything compiles and works, and I don't have a preinstalled Boost on my VM. It makes no sense at all. Does anyone have any ideas what might be happening here?

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[release][website] Help wanted
by Daniel James 01 May '18

01 May '18

Hello all, For the last couple of releases, I've been handling the releases mostly on my own, but I'm starting a new job and I'm going to have a lot less time, or maybe even no time, for Boost. So we really need more people helping with release management and updating the website. The main release manager responsibilities are described here: https://svn.boost.org/trac10/wiki/ReleasePractices/ManagerCheckList It's probably best if there are a few people involved. I don't think all of them will need admin permissions. For updating the website, you mainly need to occasionally edit html/quickbook files, accept pull requests to the release notes, and use the php scripts to updates the site at release time (I should be able to help a little there). thanks, Daniel

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Showstopper: Build broken on predef module
by Vicente J. Botet Escriba 30 Apr '18

30 Apr '18

Hi Rene, I've needed -to update to the last boost version and I'm experimenting the same issue as the one reported in https://github.com/boostorg/build/issues/299 but in my Mac. /Users/viboes/github/m_boost/libs/predef/check/../tools/check/predef.jam:46: Unescaped special character in argument $(language)::$(expression) /Users/viboes/github/m_boost/tools/build/src/build/configure.jam:288: in try-find-build *** argument error * rule log-check-result ( result ) * called with: ( ) * missing argument result Do you have an idea of what is wrong? Best, Vicente

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Need help with adding tests
by fady esam 30 Apr '18

30 Apr '18

Hi, i was working on a new opencl api for ublas and i need to add the tests and benchmarks to the ublas library. Amy help would be appreciated :) I am adding my file to the test-suite numeric/uBLAS but i want to add include directories and link 2 libraries with compiling the code.. Can anybody help me with that? Thanks in advance

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[doc] Libraries Listed by C++ standard
by Mateusz Loskot 27 Apr '18

27 Apr '18

Hi, Since each Boost library seems/is free to decide about which C++ standard they require, would it be useful to start tagging each library with standard in the release notes and docs? Perhaps new "by by C++ standard" listing could be added in here https://www.boost.org/libs/ Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[GSoC] My proposal with Boost C++ was accepted!!
by Laouen Belloli 27 Apr '18

27 Apr '18

Hi, Boost community, I was notified some days ago that my proposal for the Boost.Real project was accepted in the Google Summer of Code 2018 program. I'm currently in contact with my mentor (Damian Vicino) talking about how to start the project and how to properly work to get a clean and performant code. Any suggestion about common working methodologies in boost projects are welcome, and if there is a tutorial on the boost programming style please let me know so I can achieve a cleaner coding style that fits better with the rest of the library projects and facilitate the review process. Regarding where to store the project: I have received an invitation to join the BoostGSoC18 GitHub organization from David Bellot. Is this a good place where to create the Boost.Real project? I suppose that the organization was created for this purpose, but because I only got the invitation I don't want to create my project within the organization without asking first. Best, -- Laouen Mayal Louan Belloli. LIAA - DC - FCEyN - UBA. C.A.B.A. - Buenos Aires - Argentina. https://liaa.dc.uba.ar +54 9 11 38675694

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[config] Macro for "using" type alias defects
by Raffi Enficiaud 26 Apr '18

26 Apr '18

Hi all, I was wondering if there is any macro in Boost.Config for advertising the defect of the "using" support from the compiler. I was reported this: https://github.com/boostorg/test/pull/140 and at the time I wrote the thing, I thought that those guards would have been enough: https://github.com/boostorg/test/blob/35c9acf5bd38d625ebd45cf940c5b9a19aa22… (auto, tuple and variadic template sounds to me more difficult to support than "using" template alias). Would it make sense to have BOOST_NO_CXX11_TYPE_ALIAS? Thanks, Raffi

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Boost issue or no?
by Joshua Alexander 26 Apr '18

26 Apr '18

Hi all, I am trying to build pCloudCC and not sure if this is a Boost issue or a pCloud issue: # make [ 10%] Building C object CMakeFiles/sqlite3.dir/lib/sqlite/sqlite3.c.o [ 20%] *Linking C static library libsqlite3.a* [ 20%] Built target sqlite3 [ 30%] Building CXX object CMakeFiles/pcloudcc_lib.dir/pclsync_lib_c.cpp.o [ 40%] Building CXX object CMakeFiles/pcloudcc_lib.dir/pclsync_lib.cpp.o In file included from */root/build/console-client-master/pCloudCC/pclsync_lib.cpp:30:0*: */root/build/console-client-master/pCloudCC/lib/pclsync/pcompat.h:95:0:* *warning:*"_GNU_SOURCE" redefined [enabled by default] #define _GNU_SOURCE * ^* *<command-line>:0:0:* *note: *this is the location of the previous definition In file included from */usr/local/include/boost/smart_ptr/detail/local_sp_deleter.hpp:20:0*, from */usr/local/include/boost/smart_ptr/shared_ptr.hpp:1158*, from */usr/local/include/boost/shared_ptr.hpp:17*, from */root/build/console-client-master/pCloudCC/pclsync_lib.cpp:45*: */usr/local/include/boost/smart_ptr/detail/local_counted_base.hpp:* In member function ‘*void boost::detail::local_counted_base::add_ref()*’: */usr/local/include/boost/smart_ptr/detail/local_counted_base.hpp:67:49:* *error: **__builtin_assume*’ was not declared in this scope __builtin_assume( local_use_count_ >= 1 ); * ^* In file included from */usr/local/include/boost/smart_ptr/detail/sp_counted_impl.hpp:29:0*, from */usr/local/include/boost/smart_ptr/detail/shared_count.hpp:30*, from */usr/local/include/boost/smart_ptr/shared_ptr.hpp:28* , from */usr/local/include/boost/shared_ptr.hpp:17*, from */root/build/console-client-master/pCloudCC/pclsync_lib.cpp:45*: /usr/local/include/boost/core/addressof.hpp: In instantiation of ‘*T* boost::addressof(T&) [with T = int (*)(_IO_FILE*)]*’: */usr/local/include/boost/smart_ptr/detail/sp_counted_impl.hpp:182:98:* required from ‘*void* boost::detail::sp_counted_impl_pd<P, D>::get_local_deleter(const sp_typeinfo&) [with P = _IO_FILE*; D = int (*)(_IO_FILE*); boost::detail::sp_typeinfo = std::type_info]*’ */root/build/console-client-master/pCloudCC/pclsync_lib.cpp:304:1:* required from here */usr/local/include/boost/core/addressof.hpp:40:33:* *error: *‘ *__builtin_addressof*’ was not declared in this scope return __builtin_addressof(o); * ^* make[2]: *** [CMakeFiles/pcloudcc_lib.dir/pclsync_lib.cpp.o] Error 1 make[1]: *** [CMakeFiles/pcloudcc_lib.dir/all] Error 2 make: *** [all] Error 2

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