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Re: [boost] [Boost-users] [review][LEAF] Review of LEAF
by Niall Douglas 01 Jun '20

01 Jun '20

On 01/06/2020 12:51, degski via Boost-users wrote: > Is there scope for merging LEAF and Outcome as it seems from (very > detailed discussions) that they only partially overlap? My own opinion: 1. You may remember that Emil was one of two people who voted to reject Outcome back during its review, as he felt that it was the wrong design. His comments on what would be better back then map well onto what he has presented in LEAF. I find that very reasonable: (i) he thought he could do better (ii) he went ahead and did better in his opinion (iii) he is presenting now what he thinks is better, and is asking Boost for its opinion on whether he improved things or not. 2. There is long established precedence for Boost containing multiple libraries that approach a problem from multiple perspectives e.g. we currently have three error handling libraries, four maths libraries etc. If LEAF were accepted, you'd now have four instead of three error handling libraries. And that seems to me just fine, and not out of precedence. 3. I specifically and deliberately chose to not design Outcome like LEAF. I thought then, and I still do, that Outcome ought to be great at all the things no other solution is great at. I think I succeeded on that. As I already stated in my own review of LEAF, I personally think that there is already a perfectly good implementation of LEAF shipping in any C++ compiler of the past twenty years. I don't, personally speaking, see the value add for choosing LEAF over C++ exceptions except to tick some box called "C++ exceptions globally disabled compatible". > I don't think > that 'we' should keep on adding distinct libraries that partially > overlap, Existing libraries should be expanded instead, and > deduplication should be done in a coordinated way (in this case between > LEAF and Outcome). Something has to be done to stop exponential growth > of Boost while maintaining flexibility to add code at will. The best way to stop exponential growth of Boost, if that is desirable, is to start culling libraries that aren't maintained nor useful. Or at least publish a documented list of libraries that new code ought to not use. > As C++ already has exceptions (and will have exceptions light in the > future), the use-case you presented to use LEAF surgically with C-api's > seems convincing (it presents a better case than the case of generically > re-working an exception system that works, is fundamental to C++ and is > promised to be improved in the future, i.e. it's the safest bet. Any > library is secured till maintenance ceases, the language/STL > (exceptions, exceptions light) is a pdf-file (i.e. future proof by default). The current formulation of lightweight exceptions before WG21 is literally Experimental Outcome in language form. Same proposed error object, std::error. It is currently expected that both value-based and type-based exceptions would exist in future C++, in order to retain backwards compatibility, as the semantics between the two are not currently believed possible to be made exactly one-one. Experimental Outcome works fine in C code, same as how the most recent proposal for lightweight exceptions also supports C. Niall

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Re: [boost] Relevance of platfrom-specific shared_ptr implementations
by Bjorn Reese 31 May '20

31 May '20

On 2020-05-31 17:18, Peter Dimov via Boost wrote: > Those have been accumulated over the years and I'd like to clean them > up, remove the unused ones and fold as many of them as possible into a > few generic implementations using either std::atomic, GCC atomic > intrinsics > (https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/_005f_005fatomic-Builtins.html) > or GCC/intel sync intrinsics > (https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/_005f_005fsync-Builtins.html) How about a fall-back to Boost.Atomic?

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Re: [boost] boost reviewLEAF Review of LEAF starts today : May 22 - May 31
by Jess 29 May '20

29 May '20

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[review][LEAF] Review period ending soon - May 31
by Michael Caisse 28 May '20

28 May '20

I'd like to encourage each of you to review Emil's error handling library. We often focus on design or implementation based reviews, and I encourage those but what I would really like to see are more user based reviews. Grab the library and docs and play with it a bit. What works well? What can be improved? As a reminder, some of LEAF's features include: * arbitrary error types * header-only * no dependencies * use without exceptions * use with exceptions * no dynamic memory alloc You can find the documentation here: <https://zajo.github.io/leaf/> and the library source here: <https://github.com/zajo/leaf/tree/review> Thanks! michael -- Michael Caisse Ciere Consulting ciere.com

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[epochs] Proposal for an epoch-based organization of Boost libraries
by Joaquin M López Muñoz 28 May '20

28 May '20

Hi, Prompted by general feelings about Boost perceived lack of modernization and internal "bloat", and after an explicit survey on what users dislike about Boost [1], I decided to try and write a more or less fleshed out proposal for an epoch-based organization of Boost libraries. I've extensively tested and refined the proposal during discussions on Reddit and the Boost Slack channel, and I feel this is now ready for presentation at the mailing list: https://github.com/joaquintides/boost_epoch/blob/master/README.md I hope the proposal can start a productive conversation. Looking forward to your feedback. Best, Joaquín M López Muñoz [1]: https://www.reddit.com/r/cpp/comments/gfowpq/why_you_dont_use_boost/

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Optional library
by anshu khare 27 May '20

27 May '20

Hi mentors I was going through the optional library of boost. I was facing some problem in understanding the code base. In lines from 94 to 97 in optional.hpp, the code is as follows: struct in_place_init_if_t { Struct init_tag{}; explicit in_place_init_if_t(init_tag) {} //not able to understand this line }; I understand that we are creating a structure in_place_init_if_t and inside that we are creating another structure init_tag and then we are calling the constructor of in_place_init_if_t. But I am not able to understand that what does it the constructor do when we pass init_tag as an argument to it. Is it same as we are creating a structure Car and then creating another structure wheels inside it and passing wheels as an argument to the constructor of car as follows: struct car { Struct wheels{}; explicit car(wheels) {} //not able to understand this line }; Could you please tell what is the significance of passing wheels as an argument in this counter example?

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[LEAF] Loss of error_id
by Bjorn Reese 26 May '20

26 May '20

In the noexcept case, what happens in the Error-Handling function if the error_id generated by the Error-Reporting function is lost by the intermediate functions?

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Request for 1.73 patch release
by Richard Hodges 25 May '20

25 May '20

Dear all, Just prior to the release of boost 1.73, some changes appeared in Asio which use the new c++20 concepts (and concepts-ts) features where available. These changes have introduced breakage in Beast in compilers where concepts are enabled. Examples are gcc=10 and clang10 with -std=c++20. I have pushed a fix to beast/develop to address this, but sadly we only became aware of the problem after the release of boost 1.73.0 I suspect the cause here is a combination of my relatively new appointment as a Beast maintainer and the ground-breaking event which I am sure c++20 will prove to be. I welcome any guidance on preparing or initiating a patch release as I lack the Arcane Knowledge required. For information, here is a link to the commit which fixes the problem: https://github.com/boostorg/beast/pull/1927 And some bug reports that alerted us that somethig was wrong: https://github.com/boostorg/beast/issues/1916 https://github.com/boostorg/beast/issues/1925 -- Richard Hodges hodges.r(a)gmail.com office: +442032898513 home: +376841522 mobile: +376380212

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Re: [boost] [LEAF] The usage of TLS
by Bjorn Reese 22 May '20

22 May '20

On 2020-05-04 01:15, Andrzej Krzemienski via Boost wrote: > There is a number of reasons people do not want to or cannot use the C++ > exception handling mechanism. One of them is that the implementation of > exception handling requires the usage of TLS, and TLS is not implementable > on some platforms, like GPUs. If Nvidia's compiler does not implement C++ > exception handling mechanism, it is not because it would be slow, but > because it would require TLS support. From this perspective, if I cannot > use C++ exceptions because of TLS and I have to use something else, then > another TLS-based library is not really an alternative. In this case it > does not matter that it is only IDs that are stored in TLS. The sole fact > of even employing TLS is a deal breaker. LEAF really only needs one thread-local pointer to the topmost context per thread, so it may be possible to replace the thread-local storage with a global lock-free hash table. A lock-free hash table only requires atomic support, which is generally available on GPUs and microcontrollers. The key of the hash table could be the thread id. Task-based RTOS systems could use its task handle instead. An example of a lock-free hash table: https://eourcs.github.io/LockFreeCuckooHash/

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Re: [boost] [container] Proposal for ring queues
by Bjorn Reese 22 May '20

22 May '20

On 2020-05-22 00:17, Andrey Semashev via Boost wrote: > I would like to ask if there is interest in the community for these > kinds of containers. I know I would find them useful, and at least one > person commented in the PR to the same effect. However, I would still > like to see if more people need this. Do notice that we also have this proposal floating around: https://lists.boost.org/Archives/boost/2019/09/246925.php https://lists.boost.org/Archives/boost/2020/05/248871.php

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Help sought with identifying failure cases on the boost.org test matrix
by Richard Hodges 22 May '20

22 May '20

Dear all, Looking here: https://www.boost.org/development/tests/master/developer/beast.html We're seeing a lot of yellow, but when I run tests locally I get 100% passes. I'm reaching out to anyone who might have information on how I can replicate the steps to failure, and then either fix the problem or help the test host correct the configuration, as appropriate. Many thanks for your time. -- Richard Hodges hodges.r(a)gmail.com office: +442032898513 home: +376841522 mobile: +376380212

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[Bimap] Maintenance
by Matias Capeletto 21 May '20

21 May '20

Hello Some Boost.Bimap's maintenance PRs have remained unmerged. The library also hasn't been following additions to the STL that should be mapped in the provided containers and implementing proper support for move semantics, between other features. Since I haven't been involved in C++ for a while, I am not currently in a position to push for a new version and I would prefer to allow other people to become a maintainer. What is the process to enable other maintainers to push the library forward? Best Matias

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Review Wizard Status Report for May 2020
by Mateusz Loskot 20 May '20

20 May '20

============================================== Review Wizard Status Report for May 2020 ============================================== News ==== List of events that happened since the last report in 2016 is long and includes 13 releases of Boost, 21 libraries accepted and 4 libraries rejected. Details at https://www.boost.org/community/review_schedule.html What happened in 2020: 1. 2020-01: Ronald Garcia retired as a Review Wizard. Thank you Ronald! 2. 2020-02: StaticString accepted 3. 2020-04: Boost 1.73 Released New Libraries: - Nowide from Artyom Beilis, maintained by Alexander Grund - StaticString from Vinnie Falco and Krystian Stasiowski 4. 2020-05: Bimap library needs a maintainer https://lists.boost.org/Archives/boost/2020/05/248940.php Review Schedule Status ====================== The following libraries need a review manager: * JSON - author: Vinnie Falco, Krystian Stasiowski, Peter Dimov The following libraries have review managers, but have not yet been scheduled for review: * none The following libraries have review managers and have been scheduled for review: * LEAF - May 22, 2020 - May 31, 2020; author: Emil Dotchevski; review manager: Michael Caisse * Text - June 11, 2020 - June 20, 2020; author: Zach Laine; review manager: Glen Fernandes The following libraries have been reviewed and await reports from their review managers: * none The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Double-Ended - conditionally accepted in October 2017; author: Benedek Thaler * Parallel Sorting Sub-library - accepted November 2016; author: Francisco José Tapia The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * STLInterfaces - conditionally accepted December 2019; author: Zach Laine The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * STLInterfaces - conditionally accepted December 2019; author: Zach Laine General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email us at Mateusz Loskot (mateusz at loskot dot net) or John Phillips (johnphillipsithaca at gmail dot com). We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report, please email Mateusz. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[interprocess] Mutex and condition at process termination
by Phil Endecott 20 May '20

20 May '20

Dear Experts, Can we improve how interprocess mutexes and condition variables behave on process termination? Currently if a process terminates (i.e. it crashes, or you press ctrl-C), the interprocess docs say nothing as far as I can see about what happens to locked mutexes and awaited conditions. In practice it seems that mutexes that were locked remain locked, and other processes will deadlock. (I'm using Linux.) A few thoughts: * If a process were only reading the shared state, then it would be appropriate for the mutex to be unlocked on termination. * If a process were modifying the shared state, then it would be wrong to unconditionally unlock the mutex. So it would be useful to distinguish between reader and writer locks, even if we're not implementing a single-writer/multiple-reader mutex. * The system could be made more robust by blocking signals while a mutex is locked. This doesn't help with crashes, e.g. segfaults, but it would help with ctrl-C. * It may be useful to cause all processes to terminate if one of them terminates with a mutex held for writing, either immediately or as soon as they try to lock the same mutex. Perhaps also to delete the presumed-corrupted shared memory segment. * PTHREAD_MUTEX_ROBUST might be part of the solution. That seems to require the non-crashed process to do clean up, i.e. we would need to record whether the crashed process were reading or writing and react appropriately. I'm less clear about what happens to condition variables, but it does seem that perhaps terminating a process while it is waiting on a condition will cause other processes to deadlock. Perhaps the wait conceptually returns and the mutex is re-locked during termination. I have encountered this while trying to use a simple diagnostic program that just dumps some shared memory data structures and waits on a condition in a loop. I run this for a while and then press ctrl-C. Yes, a while after I disconnect the diagnostic program the system crashes... the worst sort of bug! Regards, Phil.

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Embarcadero PRs
by Edward Diener 20 May '20

20 May '20

I have PRs for these libraries, which have passed CI testing, for distinguishing the Embarcadero C++ clang-based compilers from the legacy bcc32 compiler: beast thread regex container python program_options units circular_buffer graph parameter unordered random typeof Can the maintainers of these libraries please merge the appropriate PR ? The PR should not affect any other compiler, and it gives a chance for the Embarcadero C++ clang-based compiler(s) to use the appropriate Boost library even when some lacking feature or Embarcadero bug currently prevents the full functionality of the library to be used.

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Re: [boost] [B2] Propagate CXX requirements to consumers
by Nikita Kniazev 19 May '20

19 May '20

> I guess this could be solved if B2 allows negation. So I can say: > `<target-os>not windows:<build>no `. > Does this exist? It is supported, but was broken until recently https://github.com/boostorg/build/pull/594

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BOOST_NO_CXX11_HDR_CHRONO?
by Frédéric 19 May '20

19 May '20

Hi, When I compile the following program: #include <boost/math/constants/constants.hpp> #include <chrono> int main() { return 0; } with a osx cross compiler based on clang 9 on linux,I get the following warnings (full output below): CAUTION: This message was generated due to the define: BOOST_NO_CXX11_HDR_CHRONO [-W#pragma-messages] This is quite strange as the compiler generates the binary which means there was no issue to find <chrono>. What's wrong then? Kind regards, F $ x86_64-apple-darwin13-clang++-libc++ -o boost_math_constants -Wall -Wextra -std=c++14 -m64 -mmacosx-version-min=10.9 -I/softs/osx64-clang-9.0.1/release/boost/include boost_math_constants.cpp In file included from Progs/boost_math_constants.cpp:1: In file included from /softs/osx64-clang-9.0.1/release/boost/include/boost/math/constants/constants.hpp:11: /softs/osx64-clang-9.0.1/release/boost/include/boost/math/tools/cxx03_warn.hpp:99:1: warning: CAUTION: One or more C++11 features were found to be unavailable [-W#pragma-messages] BOOST_PRAGMA_MESSAGE("CAUTION: One or more C++11 features were found to be unavailable") ^ /softs/osx64-clang-9.0.1/release/boost/include/boost/config/pragma_message.hpp:24:34: note: expanded from macro 'BOOST_PRAGMA_MESSAGE' # define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x))) ^ <scratch space>:307:2: note: expanded from here message("CAUTION: One or more C++11 features were found to be unavailable") ^ In file included from Progs/boost_math_constants.cpp:1: In file included from /softs/osx64-clang-9.0.1/release/boost/include/boost/math/constants/constants.hpp:11: /softs/osx64-clang-9.0.1/release/boost/include/boost/math/tools/cxx03_warn.hpp:100:1: warning: CAUTION: Compiling Boost.Math in pre-C++11 conformance modes is now deprecated and will be removed from March 2021. [-W#pragma-messages] BOOST_PRAGMA_MESSAGE("CAUTION: Compiling Boost.Math in pre-C++11 conformance modes is now deprecated and will be removed from March 2021.") ^ /softs/osx64-clang-9.0.1/release/boost/include/boost/config/pragma_message.hpp:24:34: note: expanded from macro 'BOOST_PRAGMA_MESSAGE' # define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x))) ^ <scratch space>:310:2: note: expanded from here message("CAUTION: Compiling Boost.Math in pre-C++11 conformance modes is now deprecated and will be removed from March 2021.") ^ In file included from Progs/boost_math_constants.cpp:1: In file included from /softs/osx64-clang-9.0.1/release/boost/include/boost/math/constants/constants.hpp:11: /softs/osx64-clang-9.0.1/release/boost/include/boost/math/tools/cxx03_warn.hpp:101:1: warning: CAUTION: Define BOOST_MATH_DISABLE_DEPRECATED_03_WARNING to suppress this message. [-W#pragma-messages] BOOST_PRAGMA_MESSAGE("CAUTION: Define BOOST_MATH_DISABLE_DEPRECATED_03_WARNING to suppress this message.") ^ /softs/osx64-clang-9.0.1/release/boost/include/boost/config/pragma_message.hpp:24:34: note: expanded from macro 'BOOST_PRAGMA_MESSAGE' # define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x))) ^ <scratch space>:313:2: note: expanded from here message("CAUTION: Define BOOST_MATH_DISABLE_DEPRECATED_03_WARNING to suppress this message.") ^ In file included from Progs/boost_math_constants.cpp:1: In file included from /softs/osx64-clang-9.0.1/release/boost/include/boost/math/constants/constants.hpp:11: /softs/osx64-clang-9.0.1/release/boost/include/boost/math/tools/cxx03_warn.hpp:102:1: warning: CAUTION: This message was generated due to the define: BOOST_NO_CXX11_HDR_CHRONO [-W#pragma-messages] BOOST_PRAGMA_MESSAGE("CAUTION: This message was generated due to the define: " BOOST_MATH_CXX03_WARN_REASON) ^ /softs/osx64-clang-9.0.1/release/boost/include/boost/config/pragma_message.hpp:24:34: note: expanded from macro 'BOOST_PRAGMA_MESSAGE' # define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x))) ^ <scratch space>:316:2: note: expanded from here message("CAUTION: This message was generated due to the define: " "BOOST_NO_CXX11_HDR_CHRONO") ^ 4 warnings generated.

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[Config] Swappable/Movable std::streambuf requirement
by Alexander Grund 18 May '20

18 May '20

Hello, C++11 has `std::basic_streambuf<char>::swap` and move operators for that defined. However there are stdlibs which don't support that. clang 5.0 on travis e.g. fails due to that. Is there already something in Boost.Config dealing with that case which I can `requires` on to skip the build for that case? Most of the checks I've seen in Boost.Config are using the C++ feature test macros but for this there is none. If it doesn't exist: Would this be something to be added to Boost.Config? Or my local build files? How would such a test work? Can anyone point me to a similar example? I'm having trouble navigating over the many partially auto-generated files in Boost.Config. Thanks, Alex

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Continued Fraction library/extension for Boost
by Fahad Syed 14 May '20

14 May '20

Hello, I am an Electrical Engineering fresher at National Institute of Technology, Srinagar. I have a proposal for a Continued Fraction class, with all arithmetic implemented through Gosper's HAKMEM algorithm. Here are some advantages/applications I can think of right now for a continued fraction representation: 1. Exact, base-independant representation of rationals AND irrationals (of course limited by the precision required) 2. Unlike rationals where numerator and denominator need to be "canonicalized" (i.e. divided by gcd for optimal representation), continued fraction arithmetic incorporates that naturally. 3. Approximation: Continued fraction give the best possible rational approximation for a given number 4. Comparison is extremely easy and fast 5. Conversion to float and base-conversion do not require division. Conversion to float, especially, is extremely fast and simple. I propose to implement most of the functions supported by the multi-precision library. Although I am sure there are many more applications and advantages, I would like some feedback on whether this library/extension would be of enough interest to be included in boost. Thank you.

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[Filesystem] Directory entry caching
by Chris Glover 13 May '20

13 May '20

Hi All, Whatever happened to the work in this branch https://github.com/boostorg/filesystem/tree/feature/directory-entry-cache-r… that looks to implement this paper? http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html Wondering if it's planned, dead, or looking for someone to do the work. I ran into the problem today by chance. -- chris

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[Range] Transform in place
by Frederick Gotham 11 May '20

11 May '20

Earlier today I wrote the following two lines of code: auto const my_range = v | boost::adaptors::sliced(1,15) | boost::adaptors::strided(2); boost::range::transform( my_range, my_range.begin(), std::bit_not<uint8_t>() ); However it would have been nice as a one-liner: boost::range::transform( v | boost::adaptors::sliced(1,15) | boost::adaptors::strided(2), std::bit_not<uint8_t>() ); Why isn't there a form of "range::transform" that can transform in place (and therefore takes exactly two arguments)?

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Boost.Asio's service_registry::do_use_service may block forever if a service with the same key was created
by Niklas Gürtler 11 May '20

11 May '20

Hello boost developers, I found a bug in Boost.Asio on Windows using IOCP that can make the service_registry::do_use_service block forever if a service with the same key was created and registered while the mutex was unlocked. If the service uses win_iocp_io_context, its destructor (implicitly called upon return, by destroying new_service) will join() the internal thread for IOCP handling, without requesting it to stop before. This will leave both threads to block forever, while the mutex_ is still locked (lock's destructor may be called after new_services), which may cause further blockages in other threads. I submitted a PR ( https://github.com/boostorg/asio/pull/350 ) which aims to fix this by calling shutdown() on the thread before returning, and unlocking the mutex explicitly before that. Another solution would be to call shutdown() from within win_iocp_io_context::~win_iocp_io_context(). Regards, Niklas Gürtler

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Boost and unsigned chars
by REIX, Tony 11 May '20

11 May '20

Hi, I have tried to build Boost, and mainly Boost.math, with -funsigned-char, and I’ve faced several issues. Is Boost designed to work with unsigned chars (default on AIX) in addition to signed chars (default on Fedora)? Thanks Tony

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Google Summer of Code 2020 selected projects
by David Bellot 09 May '20

09 May '20

Dear Boost community, I would like to welcome our Google Summer of Code. 2020 students. This year, 10 students will work very very hard on improving and adding new features to many of our libraries. Once again, the competition has been very hard. A few numbers: - we received 93 proposals in total. 85 of them were complete, then we kept 47 proposals only - finally we selected 10 of them, covering 7 different Boost libraries - and countless hours of work from the most incredible team of mentors! Here are the list of projects for 2020: *Boost.Real* Kishan Shukla will be working on making the Real library ready for revision. His main goal is to reimplement the division algorithm so it can be used with any number base representation and the Karatsuba multiplication algorithm. Also, it will be working on implementing some operators and common irratianal numbers as Pi. Mentors: Laouen Belloli and Damian Vicino. *Boost.Astronomy* Syed Ali Hasan will be working on the astronomical coordinate system, he will implement different coordinate conversion using SOFA library Mentor: Pranam Lashkari Gopi Krishna Menon will be completing the parser for FITS file and also optimise the already developed components. Mentor: Sarthak Singhal *Boost.GIL* Debabrata Mandal will be implementing histogram computation as a built-in feature, algorithms for histogram analysis, image processing algorithms based on histogram and possibly integration with Boost.Histogram library. *Mentor*: Mateusz Loskot, Pranam Lashkari Olzhas Zhumabek will be extending GIL's portfolio of image processing algorithms, implementing for image scaling and sampling, Perona–Malik diffusion, Non-Maximum Suppression for object detection, Hysteresis threshold and some more. *Mentor*: Mateusz Loskot *Boost.Multiprecision* Dimitris Los will work on extending and optimizing parts of Boost.Multiprecision to higher precision of many thousands of bits or more. *Mentor*: Christopher Kormanyos *Boost.uBlas* Ashar Khan will stabilize and improve Boost.uBlas using the C++20-Standard. The main focus of his project will be enhancing code-coverage and documentation, integrating static code analysis and generating tensor concepts. *Mentor*: Cem Bassoy Tom Kwok will improve and finalize the implementation of data frames in uBlas, with the aim of delivering production-ready by the end of the summer. Data frame in uBlas are similar in functionalities to other implementations like in R, Python.Pandas or Julia. *Mentor*: David Bellot *Boost.Geometry* Tinko Bartels will work on robust yet efficient geometric predicates for Boost Geometry. *Mentor*: Vissarion Fisikopoulos *Boost.Real* Vikram Singh Chundawat will work in taking Real to revision ready state. His focus will be in improving the internal representation datatypes and providing functions required to conveniently support Taylor series. *Mentors*: Damian Vicino and Laouen Belloli Best regards, David Bellot

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[github] Retriggering CI tests
by Edward Diener 08 May '20

08 May '20

How does one retrigger CI testing for a PR on Github without having to artificially update the PR ? I tried to find the answer to this in Github Help with no success. Maybe you have to retrigger tests within the testing environment somehow but I could not see how in either Appveyor or Travis CI.

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