February 2020 - Boost - lists.preview.boost.org

Adding my sorting algorithm, ska_sort, to boost, attempt 2
by Malte Skarupke 24 Nov '21

24 Nov '21

Hi everyone, I started a discussion about this in October, but at the time the maintainer of the sort library was busy, then I was busy, so now it's January... I wrote a generalized version of radix sort a couple years ago and gave a talk about it here: https://www.youtube.com/watch?v=zqs87a_7zxw I would like to get a new version of that sorting algorithm into boost. It's faster than what I showed several years ago. It's also even more general and has a new interface that should be easier to extend. I uploaded the code here: https://github.com/skarupke/sort/tree/master The documentation is also already updated with new benchmark results. Let me know what's required to get this into boost. Would you like this in the form of a pull request? One of the big things that probably needs review is the interface, since radix sorting works differently than comparison based sorting. For most normal uses you just need to provide a sort key, but more complicated cases can get more complicated. I tried very hard to make everything easy, but I'd also be curious if others can come up with better ways of doing the interface. Thanks, Malte -- Malte Skarupke malteskarupke(a)fastmail.fm

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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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Hiring mentors for Google Summer of Code 2020
by David Bellot 28 Mar '20

28 Mar '20

Hi Boost community, we are recruiting the mentors for the Google Summer of Code 2020. If you wish to be a mentor, please contact me directly and I'll send you an invite. We need at least 10 mentors this year. Obviously, a mentor comes with ideas of projects and proposals for this Summer. Best regards, David

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binomial distribution setter function
by Kemin Zhou 18 Mar '20

18 Mar '20

This is my first time posting in this mailing list. Not sure how to post to the developer only mailing list after reading the document for mailing list for a good half an hour. If I posted in he wrong mailing please let me know and kindly provide the developer mailing list. I am looking at the binomial.hpp file. I need to use the binomial object in a loop which requires to have high performance. I am thinking constructing the binomial object each time in the loop would be less efficient than if I construct a single object, the each time reset the p parameter and use the object. I am not sure why the setter method was not provided. 296 RealType success_fraction() const 297 { // Probability. 298 return m_p; 299 } 300 void set_success_fraction(RealType p) { 301 m_p=p; 302 } Line 296 is the getter method, I added the setter method at line 300. -- Kemin Zhou 858 366 8260

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boost thread strange behaviour
by Adham Sabry 08 Mar '20

08 Mar '20

hi , i am trying to learn executors and executors thread pools using with boost::async but i found strange behabiour when i make thread pool adaptor ea and submit tasks to it and make ea00 and submit tasks to it if i started ea with async , it automatically starts ea00 the attached file has the code i thought that async will only start the passed thread pool"adaptor" But i think there is underlying thing which gather all threads of different pools into single entity and starts them with any call to boost::async is this a bug??? i run this from windows 7 64 by visual studio 2017

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Boost.StaticString (formerly Boost.FixedString) is ready for release!
by Krystian Stasiowski 02 Mar '20

02 Mar '20

Hi all, After some post-review polishing, Boost.StaticString is good to go for release! I have been in touch with the review manager, and everything has been checked over. Repo: https://github.com/sdkrystian/static_string Docs: https://sdkrystian.github.io/doc/static_string Here are some things that have been changed post-review: - Library has been renamed from Boost.FixedString to Boost.StaticString. Class template fixed_string has been renamed to basic_static_string, and aliases have been added for common character types, similar to std::string. - constexpr support to the fullest extent supported by available compilers has been added. - Functions that will not throw have been marked noexcept. - Moved to a single header configuration. - std::hash and boost::hash_value support has been added. - It has been decided that functions will throw on capacity overflow. - A specialization for when the capacity is 0 has been added that has no member. Additionally, the type of the member used to store the size of the string is now statically chosen to be the smallest possible width unsigned standard integer type that can hold all the needed size values. - operator+ has been implemented. - Floating point conversion support has been added to to_static_string/to_static_wstring. - Lots of bugs fixed. More behind the scenes, a bunch of optimizations have been added, taking advantage of the fact that the capacity is part of the type and known at compile time. Again, thank you all who participated in the review, and thank you Joaquin for managing it! Regards, Krystian Stasiowski

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Projects for GSoC 2020
by David Bellot 01 Mar '20

01 Mar '20

Hi Boost community, so far we received a few good contributions for projects for GSoC 2020. The proposals are from our usual mentors but I'm surprised we don't have more projects in data structures and algorithms. Most of what we have concern numerical problems. It's great but I wish to see more diversity in the type of projects we propose. We want to attract the best students around the world and push toward new C++ standards and improvements of what we already have. Being a mentor is a great experience and on top of it, without too much effort, you will get someone of quality working for you during all the summer. The wiki page for projects is here: https://github.com/boostorg/wiki/wiki/Google-Summer-of-Code%3A-2020 Please come, edit and contribute. Cheers, David

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What is the right way to close and clean boost::log
by JH 01 Mar '20

01 Mar '20

Hi, I built boost::log in my application library, it created boost::log::sinks::synchronous_sink<boost::log::sinks::text_file_backend> and close it by calling the boost::log::core::get()->remove_all_sinks() in destructor of the Log library, then one of my application link to my log library got Segmentation fault when it exited: Program received signal SIGSEGV, Segmentation fault. 0x00007ffff5fdd961 in boost::log::v2_mt_posix::core::remove_all_sinks() () from /usr/lib/x86_64-linux-gnu/libboost_log.so.1.65.1 If I add boost::log::core::get()->remove_all_sinks() in my application main before it return 0, the segmentation was gong, but it stuck. What is the proper right way to close and clean the boost::log? There is a blog suggested to run boost::log::core::get()->remove_all_sinks() when the main end, but that does not seem work. https://www.boost.org/doc/libs/1_62_0/libs/log/doc/html/log/rationale/why_c… Thank you. Kind regards, - jupiter

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Cryptography for Boost.
by Mikhail Komarov 29 Feb '20

29 Feb '20

Hello! Cryptography for Boost. Again. It’s been some time since I’ve started developing so-called clean C++ cryptography implementation for my organization’s internal purposes. It was intended at first to be a cryptography framework fulfilling special cryptography schemes requirements, but eventually it has evolved into a full-featured suite, actively using and, sometimes, even based on Boost libraries. This turned out to be fine way to serve the Boost (and entire C++) community and to assemble a Boost version of a suite. So this letter is about wether there is still any interest in cryptography library for Boost and is there any sense to show the community what do I have for now? Sincerely yours, Mikhail Komarov nemo(a)nil.foundation

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[gsoc] Encourage original ideas
by Mateusz Loskot 29 Feb '20

29 Feb '20

Hi, I noticed there may be confusion among students regarding project ideas. I sense, students (sometimes) fail to find the GSoC guides [1] ... So, based on the first paragraph of [1], I have updated our wiki [2] placing this note to students: "To any potential students, in addition to the list of project ideas, we don't discourage original ideas proposed by students. " If any mentors here disagree, please let me know and I will remove it (or move it to GIL, which I'm involved with as a mentor). [1] https://google.github.io/gsocguides/student/finding-the-right-project [2] https://github.com/boostorg/wiki/wiki/Google-Summer-of-Code:-2020 Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Who's using Boost
by Adam Getchell 28 Feb '20

28 Feb '20

Name: CDT-plusplus [1] Company: University of California Davis CDT-plusplus generates ensembles of quantum spacetimes under the Causal Dynamical Triangulations program using the Metropolis-Hastings algorithm, with other algorithms planned. These ensembles allow calculations of quantities such as the spectral dimension and the overall transition amplitudes from the beginning until the end of time for a simulated universe of given dimension and volume. Many different research problems may be answered with these ensembles, including the existence of a Newtonian limit in CDT [2], renormalization group flow in CDT, [3] and spontaneous dimensional reduction in short distance quantum gravity. [4] Where Boost is used: 82 Boost libraries are used in conjunction with CGAL [5] in order to perform accurate geometric and combinatoric operations on 3 and 4-dimensional Delaunay triangulations. Boost.Optional and Boost.Outcome are used to assist in correctness guarantees for billions of moves permuting triangulations on simulations running for months on High Performance Compute clusters. [6] [1] https://github.com/acgetchell/CDT-plusplus <https://github.com/acgetchell/CDT-plusplus> [2] https://ui.adsabs.harvard.edu/abs/2015APS..APR.X7006G/abstract <https://ui.adsabs.harvard.edu/abs/2015APS..APR.X7006G/abstract> [3] https://arxiv.org/pdf/1405.4585.pdf <https://arxiv.org/pdf/1405.4585.pdf> [4] https://arxiv.org/pdf/0909.3329.pdf <https://arxiv.org/pdf/0909.3329.pdf> [5] https://www.cgal.org/ <https://www.cgal.org/> [6] https://www.hpc.ucdavis.edu/ <https://www.hpc.ucdavis.edu/> Let me know if further information is needed. -- Adam Getchell, M.S. https://adamgetchell.org <https://adamgetchell.org/>

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GSoC, Boost C++ and Slack channel
by David Bellot 28 Feb '20

28 Feb '20

Hi Boost community, we have a dedicated channel on Slack for all the discussions regarding the Google Summer of Code. Please join us on cpplang.slack.com on the channell #boost-gsoc. Cheers, David

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Re: [boost] Cryptography for Boost.
by Kenneth Porter 26 Feb '20

26 Feb '20

--On Friday, February 21, 2020 6:21 PM +0300 Mikhail Komarov via Boost <boost(a)lists.boost.org> wrote: > It's been some time since I've started developing so-called clean C++ > cryptography implementation for my organization's internal purposes. It > was intended at first to be a cryptography framework fulfilling special > cryptography schemes requirements, but eventually it has evolved into a > full-featured suite, actively using and, sometimes, even based on Boost > libraries. This turned out to be fine way to serve the Boost (and entire > C++) community and to assemble a Boost version of a suite. How does it fit in with openssl and SASL? I'd been contemplating dipping my toes into a Windows email client and openssl has a native Visual Studio port but I don't know of one for any SASL libraries. So the available open source email libraries tend to be *nix-oriented and have to be built with a ported *nix toolchain.

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Start with Boost Multiprecision
by Tarun Lahrod 25 Feb '20

25 Feb '20

Hello, I am Tarun Lahrod. An engineering undergrad who's willing to contribute to Boost Multiprecision library in GSoC 2020. Please help me where to start from. Even in the code base from where should I start it. I am very much interested in taking Multiprecision as a project. Please help me start. Thank you. Tarun Lahrod Computer Science and Engineering (CSE) Bharati Vidyapeeth's College of Engineering, New Delhi Linked In: www.linkedin.com/in/tarun-lahrod GitHub: github.com/tarunlahrod

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Related to Boost.Real Project Proposal
by Vikram Chundawat 25 Feb '20

25 Feb '20

Hey everyone, I am Vikram Singh Chundawat. I have a decent programming experience in c++. I am interested in Boost.Real project proposal and I want to work on this project in GSoC 2020. I have good knowledge of data structure and algorithms. I am going through all references and blogs suggested on project site currently. I will prefer giving the competency test after 8 march as I have my exams till then. It will be great if you have any suggestions regarding the prerequisites of this project, till then i will be going through the resources given on the project page. Thank you Regards Vikram Singh Chundawat

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[website] 1.72 Boost.Config docs are missing
by Andrey Semashev 25 Feb '20

25 Feb '20

Hi, On this page: https://www.boost.org/doc/libs/1_72_0/ following Boost.Config link: https://www.boost.org/doc/libs/1_72_0/libs/config/config.htm leads to 404 Page Not Found. I believe the correct link should be: https://www.boost.org/doc/libs/1_72_0/libs/config/doc/html/index.html

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[GSoC] My piece of advice to students
by Mateusz Loskot 24 Feb '20

24 Feb '20

Dear Student, You are planning to participate in GSoC and develop some new features for the Boost libraries. Awesome! So, you want to introduce yourself to the community as soon as possible. Awesome! However, before posting your first question to the Boost mailing list, please, do read the official GSoC student guides [0]. All of it. [0] https://google.github.io/gsocguides/student/ I also recommend to read through other resources dedicated for students, especially this one from Google [1], one from a former student [2] as well as advice from Boost GSoC former student Louis Dionne [3]. [1] https://opensource.googleblog.com/2011/03/dos-and-donts-of-google-summer-of… [2] https://medium.com/@akshikawijesundara/google-summer-of-code-dos-and-do-not… [3] https://github.com/boostorg/wiki/wiki/Google-Summer-of-Code%3A-Advice-From-… Once you get through the general GSoC materials, it's a good idea to start browsing Boost resources, from intro [3] through netiquette [4] to wiki [5]. On [3] and [5] you will find links to past and current project ideas for Boost libraries. Browse it, read it, and learn what kind of projects Boost community develops during GSoC. Start thinking about what interests you, which Boost library, which project, what you'd like to develop as GSoC student. [4] https://www.boost.org/community/gsoc.html [5] https://www.boost.org/community/policy.html [6] https://github.com/boostorg/wiki/wiki Meanwhile, it's a good idea to "Make First Contact" [0]. Subscribe to the boost (developers) and boost-user or library-specific mailing list at https://lists.boost.org join Boost channels on Slack at https://cppalliance.org/slack/ and start discussing your participation, project ideas, etc. Although the student guides [0] use the phrase about "communicating directly with potential mentors", it does NOT mean exchanging private e-mails with mentors asking "Are you interested to mentor me?". GSoC does not work this way. In my opinion, the word "directly" means to interact directly with the community where, obviously, potential mentors are members too. The Boost organization and mentors will have chance to select students and projects they wish to mentor during the selection process - a secret, you can learn about it from GSoC guides for mentors [8]. Yes, the selection is a competitive process. [8] https://google.github.io/gsocguides/mentor/selecting-a-student Next, start discussing project of your interest, start asking questions, investigate ways to contribute to Boost, start working on competency tests Mind you, competency test is Boost way to verify minimum necessary skills. I personally think Boost should also ask for a bug fix [2] explains: "Some organizations make it a must for you to fix a bug in their code base before submitting a proposal but some do not. Your chances are always high if you can fix a bug in the code." Submitting a pull request with a small feature is also a good idea, something to discuss with mentors/maintainers of library of your interest Pull requests will allow you to gain hands-on experience with workflow of peer reviews, continuous communication, addressing problems, testing your solution, using the infrastructure, being exposed to stress of 'annoying' requests from maintainers to fix this, tweak that... :-) For example, it worked well for Boost.GIL (you can PRs at https://github.com/boostorg/gil) "you have to go early even if you go to hell" [2] GSoC IS hard work! Make sure to start early, to take a proactive stance, to do your homework before you start asking questions, to expect no babysitting. Imagine the GSoC runs back in times when there is no StackOverflow, no web archives, no web search,... There really is no excuse for not searching the web first nowadays. Even compilers can do that! https://arxiv.org/abs/1906.11456 "To grow in life, be willing to suffer" ~David Goggins Have a great time during GSoC and good luck! Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[static_string] Boost.StaticString (fka FixedString) accepted into Boost
by Joaquin M López Muñoz 24 Feb '20

24 Feb '20

Hello, Boost.StaticString (formerly known as FixedString) was accepted into Boost subject to the resolution of a number of issues I listed as priority 1: https://lists.boost.org/Archives/boost/2019/12/247820.php I've checked with the author that these issues have been already solved, so Boost.StaticString is good to go as an official Boost library (hopefully in time for shipping with 1.73). Thanks to Krystian and Vinnie for their work. Welcome Krystian to the dubious club of Boost authors :-) After the hard work needed to get the lib in, now comes the not less hard part of keeping it updated and generally healthy. Best regards, Joaquín M López Muñoz Review manager for candidate Boost.FixedString (now Boost.StaticString)

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[gsoc2020][Boost.GIL] Advice needed regarding competency.
by sarthak 23 Feb '20

23 Feb '20

Hi everyone, I am Sarthak, a second year undergraduate engineering student. I wish to contribute to boost open source development during gsoc2020, specifically to Boost.GIL. But, I am not sure whether I am competent enough to contribute meaningfully to the organization (see the last point for precise question), I am hoping that someone here can give me advice regarding the same :) First, my reasons to contribute to boost - - I am reasonably proficient in programming (C++ included). I know I will be able to demonstrate it through programming competency test and all. In my day to day programming I normally do not use meta programming techniques which are prevalent in boost, this has made me more excited to work on boost because I will get to use these new fancy constructs :D - I just want to be part of open source community for once, sincerely. I have been using FOSS since forever and as a developer I have been longing to pay back, this is a good chance for me to do the same. - Why boost over any other organization? Largely because C++. I like the multi-resolution philosophy of C++ that you can get as close to machine as possible, or you can do high level manipulations through libraries and generics. More on that in proposal ;) - Why GIL (Project 1)? I want to learn image processing. Now this is where it gets tricky, the thing is that I am passionate about doing image processing, but I am not well versed with its theory. I have done a course on Signals and Systems in my university but that is pretty much it. This means that at the least I would need to learn image processing algorithms as we go on. Not that I hate it (on the contrary in fact) but that I am not really sure if it is possible at all for someone like me to contribute meaningfully during the few months of GSoC. I would love to hear from a mentor's experience of previous students on this. Honestly I would like to be rejected now if at all than after submitting my proposal with false hopes, or worse moving on with GSoC with such false hopes. I can also contribute to boost multiprecision in which I am substantially more experienced, but my first interest is in GIL and therefore if possible I would like to take the project in GIL. Any advice is appreciated. Thanks for reading. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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Fwd: Open Source Hackathon Mentor Invitation
by David Bellot 23 Feb '20

23 Feb '20

A word from our friends doing C++ at Hackillinois Outreach... ---------- Forwarded message --------- From: Advai Podduturi <advai.podduturi(a)hackillinois.org> Date: Wed, Feb 19, 2020 at 7:56 AM Subject: Open Source Hackathon Mentor Invitation To: <david.bellot(a)gmail.com> Hello, My name is Advai Podduturi and I’m reaching out on behalf of the HackIllinois Outreach team. HackIllinois is a 36-hour collegiate Open Source hackathon that takes place annually at the University of Illinois Urbana-Champaign. This year, it will be from February 28th - March 1st, 2020. Our mission is to introduce college students to Open Source, while giving back to the community. We strive to create a collaborative environment in which our attendees can learn from and work with developers to make their own contributions. In past years, we’ve had developers from prominent projects such as npm, Rust, and Apache come to mentor students from our pool of 900+ attendees. We’d love it if you could pass along this message to the Boost C++ community or any individuals you believe would be interested. We will provide meals throughout the event and can reimburse for travel and lodging up to a certain amount depending on where in the US people are coming from. More information on mentorship can be found at hackillinois.org/mentor <http://ec2-52-26-194-35.us-west-2.compute.amazonaws.com/x/d?c=6287904&l=b31…>. You can also visit opensource.hackillinois.org <http://ec2-52-26-194-35.us-west-2.compute.amazonaws.com/x/d?c=6287904&l=360…> to see what kinds of projects were represented at our event last year. Sincerely, Advai Podduturi -- Advai Podduturi HackIllinois 2020 | Outreach Team advai.podduturi(a)hackillinois.org | 630-765-4099

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[GSoC20] logo
by Pranam Lashkari 22 Feb '20

22 Feb '20

Our logo on the GSoC page[1] looks a little pixelated and small fonts are not readable can we replace it? I have attached a boost logo file in the mail and a transparent logo can also be found here[2] [1]: https://summerofcode.withgoogle.com/organizations/6011808097239040/ [2]: https://de.wikipedia.org/wiki/Boost_(C%2B%2B-Bibliothek)#/media/File:Boost.… Thank you, Pranam Lashkari

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Extend and optimize Boost.Multiprecision to higher precision of thousands of bits or more.
by Shubham Agarwal 21 Feb '20

21 Feb '20

Hello, I read the documentation for the Boots.Multiprecision and found it interesting, and I'M willing to work on this for Gsoc. could you please help me to get started.

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Boost. Multiprecision:Multiprecision Big Number Types
by Ashmita Singh 21 Feb '20

21 Feb '20

Hello everyone, I explored about this project and found it interesting and i am interested to work on it for GSOC 2020.Can someone please help me out in getting started? Thank you Ashmita Singh

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GSOC2020
by Damian Vicino 20 Feb '20

20 Feb '20

Hi everyone, Boost is once again in Google summer of code! https://summerofcode.withgoogle.com/organizations/6011808097239040/ Thanks David and everyone participating in the proposal for this year.

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Starting contribution at boost
by Ashmita Singh 14 Feb '20

14 Feb '20

Hello everyone, I am a beginner in open source contribution.I want to start my career in open source contribution with boost organisation.So please help me out with a project to which i can contribute.My preferred language is C++. Regards.

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