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Trouble getting feedback on a program_option feature PR
by Eyal Rozenberg 05 Mar '18

05 Mar '18

Hello Boosters, Following a (much) earlier suggestion on this list, I've implemented one of the features I'd like to see in program_option, and created Pull Request for initial review/feedback on GitHub: https://github.com/boostorg/program_options/pull/40 I've noticed, however, that there are 4 other unattended PRs, the earliest being from 2016. Some of them have comments such as "Can you please merge or decline?" urging a response. Also, there have been no commits for the past 4 months. I've also emailed Vladimir (Prus) last month - a short message, merely to ensure he's noticed my PR, not to demand anything; but I've gotten no reply. Now, I don't want to sound accusatory - I'm sure there are perfectly good reasons for the lack of responsiveness, and I'm very appreciate of the work of writing the library and maintaining it over the years. Still, given the situation I thought I'd bring this up here on the list. What would you suggest I do? Eyal

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Gsoc2018/mentor required
by nivyatheresa 05 Mar '18

05 Mar '18

Hello, I am Nivya and I am a btech student from IIT Roorkee. I would like to contribute to the Boost.Real project. I need a mentor to help me to proceed further. Thanks in advance, Sincerely, Nivya. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[serialization] RTTI issue with non-polymorphic types
by Jorge Lodos 05 Mar '18

05 Mar '18

Hi I am trying to use the serialization library for non-polymorphic types without RTTI. In release mode everything works fine, but in debug mode there are problems because dynamic_cast is used for debugging purposes. The code is in smart_cast.hpp, starting in line 87: #if ! defined(NDEBUG) \ || defined(__MWERKS__) // do a checked dynamic cast return cross::cast(u); #else I believe the first line could be replaced with: #if (! defined(NDEBUG) && ! defined(BOOST_NO_RTTI) ) \ Is this something you are willing to consider? I decided to ask before creating any ticket or pull request because there is a number of previous attempts to make serialization work without RTTI for the general case. But this is specific for non-polymorphic types. Thanks. Jorge

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Re: [boost] Proposed SG14 <system_error2> ready for feedback
by Bjorn Reese 04 Mar '18

04 Mar '18

On 02/28/18 23:10, Niall Douglas via Boost wrote: > 7. `std::error_code` enforced its value to always be an `int`. This is > problematic for coding systems which might use a `long` and implement > coding namespaces within the extended number of bits, or for end users > wishing to combine a code with a `void *` in order to transmit payload > or additional context. As a result, `status_code` is templated to its > domain, and the domain sets its type. A type erased edition of > `status_code<D>` is available as `status_code<void>`, this is for > obvious reasons non-copyable, non-movable and non-destructible. > > A more useful type erased edition is `status_code<erased<T>>` > which is available if `D::value_type` is trivially copyable, `T` is an > integral type, and `sizeof(T) >= sizeof(D::value_type)`. This lets you > use `status_code<erased<T>>` in all your public interfaces without > restrictions. As a pointer to the original category is retained, and > trivially copyable types may be legally copied by `memcpy()`, type > erased status codes work exactly as normal, except that publicly it does > not advertise its type. While I do see the need for providing extensions, I am not sure if status_code<void> is useful given all its "non-" characteristics. Can you elaborate on its use-cases? I propose that the customizable status_code<D> is renamed to basic_status_code<D>. In keeping with the pre-established practices of std::error_code using int, I furthermore suggest that status_code becomes a non-templated alias for basic_status_code<int>.

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Gsoc2018/Mentor required.
by nivyatheresa 04 Mar '18

04 Mar '18

Hi, I am Nivya Theresa Jose, b-tech student from Indian Institute of Technology Roorkee. I would like to contribute to boost.uBLAS project 1, which is to add support for tensors .I would like to connect with a mentor and would like to know about further procedures. Thanks in advance, sincerely, Nivya Theresa Jose. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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Help/Mentor required
by Devika Krishnadas 04 Mar '18

04 Mar '18

Hi, I am Devika Krishnadas, an Undergrad Computer Science student from Amrita University. I am interested in contributing to boost.uBLAS project #1, which is to add Statistics and Machine learning functions. It would be great if anyone could help me proceed further. Thanks in advance, Regards, Devika Krishnads.

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gsoc2018 inquiry and mentor seeking
by fady esam 04 Mar '18

04 Mar '18

Hello, I am Fady Esam student at 3rd year of computer engineering in ASU university in Egypt I want to cobtribute the the project of "Adding multicore and gpu computations to uBLAS" As i was the team leader and main contributer in an open source library for complex-numbers matrices that has the same parsing and interface as matlab and supports all operations like computing inverse by gaussian elimination and determinant by LU decomposition and +, - , * ,/ , .* , ./ and computing power of matrix in a very optimized way That's a github link to the library : https://github.com/boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018 I want to know do i have to implement part of the library again in template for the competency test? And is there a mentor that is interested so i can submit a proposal to? Thanks for reading :)

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[interprocess] file_mutex class proposal
by mateusz janek 04 Mar '18

04 Mar '18

Hello boost::interprocess community, During my pet projects development I found that a file access synchronization is a common problem so, I wrote a class that wraps it and thought that it can be useful for wider community. I would like to ask you what do you think about such functionality in boost::interprocess? I'm aware that class from the repo is not ready to release. Just wanted to show about what functionality I'm talking about. Here you can find the repo: https://github.com/stryku/file_mutex You can find there the proposed class and a simple usage example. If you will find it interesting I will prepare more formal merge proposal, update docs, maybe more examples etc. Looking forward to hearing from you what do you think about it. Thank you, Mateusz Janek

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Which headers to include?
by Lakshay Garg 03 Mar '18

03 Mar '18

Hello Boost I am using a few Boost libraries in a project I am working on. I must confess that this is perhaps my first serious use of boost so all this could just be due to lack of familiarity. The one thing that keeps frustrating me about boost is finding out _which headers to include?_ I am not sure if this is a problem with my googling skills or library documentation or maybe I just don't know the proper place to look at but most of the times I need to use a library with lots of headers (I am looking at Boost.Log) I have to go grepping the boost code. Is there something I am missing or is there a better way to go about this problem? Lakshay

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why boost does not have skip list implementation?
by David Frank 03 Mar '18

03 Mar '18

like java concurrentSkipListSet for example. Thanks, David

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past few days coding:=>>makefile generator
by Ggh 03 Mar '18

03 Mar '18

#-------------------------------------------------------------------------------- # # Command Line Options: # # For each argument add a space between the switch and the argument to the switch, # e.g.: # # mkmakefile -tt exe -t targetname # # mkmakefile --help # # -tt <exe|dynamic|objs|static> Target type # -t <targetname> Target name # -i <include directory> Include directory # Include directories can be several. Prepend # each directory with an '-i' # -L <library directory> Library directory # Library directories may also be several, prepend each # directory with an '-L' # -l <library name> Library name, may also be several, prepend each # library with '-l'. # -d <define> Define # May also be several, prepend each define with '-d'. # -hd Header dependencies # This flag makes the generator scan # the source files for header files # included. Creates dependency rules # in the generated makefile. # If a header file is included in a source file # and found in any of the include directories given # it will be listed as a dependency to the source file. # -o <makefile filename> Makefile filename to generate # -c <c compiler> C compiler, the compiler needs to be in the PATH # environment variable. # -cc <c++ compiler> C++ compiler, the C++ compiler needs to be in # the PATH environment variable aswell. # -sl <static library> Link to static library # The number of static libraries can be any. # Prepend each library name with an '-sl' tag. # -wd <target directory> Target directory. The program changes # to the target directory, creates the makefile # and reverts back to the directory it was # started from. The makefile is written # to the target directory. If this argument is # not set then the current directory will be used. # -mk Make the program / library. This option executes # 'make' with the make file given. If no makefile # argument is given it will use 'makefile.mk' by # default # # -help This help information # #--------------------------------------------------------------------------------

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[gsoc18]project1-1: Add statistics and machine learning functions
by SheldonZhang 02 Mar '18

02 Mar '18

Hi, My name is Zhang Bohan(Sheldon Zhang) from China. I am a freshman in Beijing University of Posts and Telecommunications, majoring in Information and Communication Engineering. I want a mentor who can guide me to accomplish the project. I am interested in working for Boost.uBLAS because in my profession there are plenty of calculation about matrix. I believe this will lead me to better understanding about it. And I love machine learning, it is the way to the future. I am taking a machine learning course(taught by Andrew Ng) on coursea. So I know what I am going to do in the project. I do quite well in Linear Algebra. In the exam, I got top 10% in the grade. I have been programming since junior high school. I am familiar to C++-11 and its features(like lambdas and template). I have good command of basic algorithms. I participated in National Olympiad in Informatics and got good grades. Besides, I am a teaching assistant in Program Designing Course. I am googd at English, so there is few difficulty in communicating. I have done the programming competency test https://github.com/ltg001/gsoc18-codeCompetencyTest At last, what should I do in this period? With regard, Sheldon Zhang -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[gsoc18] [Boost.Real] Competency Test
by Parth Mittal 02 Mar '18

02 Mar '18

Hi My name is Parth Mittal, and I'm a third year computer science undergraduate. Here is my attempt at the competency test: (wrt the first, second, and third bullet on the project page) 1. I uploaded my code here (https://github.com/parthmittal/boost_competency_test) I'm not sure how much of it is required to be functional but (of course) I can write more code if required. The current code uses an std::pair of the chosen rational type to represent intervals, it is probably more sensible to replace this with a dedicated type for intervals. Also I have two different ideas for dealing with integers in the binary operators: (i) Wrap them into a "real" number (with an approximation function that always returns the exact value and an error term of 0). (ii) Add a facility for additive and multiplicative rational factors to the class. 2. For sure there is no way to be sure two numbers are equal in finite time, so while checking if a and b are equal, we should pass an integer parameter, say K, and then for every pair of integers i, j between 1 and K, we should check if a(i) = b(j) (of course a(i) = b(j) iff the intervals share a point). This feels somewhat inefficient (it would be nice to eliminate the quadratic runtime with K), but since we don't have a guarantee that a(i + 1) is a subset of a(i), I don't see any obvious way to improve this. 3. To be honest, I had to google for "Small String Optimization" - and the analogue I can see is to store as an array the values of a(k) for all k <= K for some small constant K. I'm not sure how to implement this at compile time; it makes sense that the approximation function(s) for the real number involved be constexpr, but I've never written any code which is constexpr. Perhaps my code in (1) already makes this clear, but I'm not very experienced at writing C++; I've written probably 100k+ lines while doing programming contests, but this was rather simple code which was written once and read never. I can fill in the gaps in my knowledge of the language on an ad-hoc basis (or using the time until the SoC officially begins). Thank you for reading Parth Mittal

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Boost Performance
by Ian Kosen 01 Mar '18

01 Mar '18

Hi, I was looking at this benchmark https://github.com/mloskot/spatial_index_benchmark <https://github.com/mloskot/spatial_index_benchmark> which attempts to compare the performance between Boost and LibSpatialIndex. It caught my eye that Boost was magnitudes faster than LibSpatialIndex. Is there an obvious reason for this? Design considerations and trade offs? Thank you :) Regards, Kosen

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[teeks99-09-p-win2016-64on64][poly_collection] Regression with latest MSVC 14.1 in C++17 mode
by Joaquin M López Muñoz 28 Feb '18

28 Feb '18

Hi, MSVC 14.1 (_MSC_FULL_VER=191225834) in C++17 mode (_MSVC_LANG=201704L) is having a regression when compiling Boost.PolyCollection tests: http://www.boost.org/development/tests/develop/developer/output/teeks99-09-… The problem happens in this seemingly innocent context (https://github.com/boostorg/poly_collection/blob/654018c7ce14674a1c0527206a… ): template< typename ForwardIterator1,typename ForwardIterator2,typename Predicate > bool operator()( ForwardIterator1 first1,ForwardIterator1 last1, ForwardIterator2 first2,Predicate pred)const { ... using difference_type= typename std::iterator_traits<ForwardIterator1>::difference_type; difference_type l1=std::distance(first1,last1); // syntax error (wrongly) signalled here Is there some kind soul with access to this compiler who'd like to try the following workarounds and report the results? // workaround 1 using difference_type= typename std::iterator_traits<ForwardIterator1>::difference_type; typename difference_type l1=std::distance(first1,last1); // workaround 2 typedef typename std::iterator_traits<ForwardIterator1>::difference_type difference_type; difference_type l1=std::distance(first1,last1); Thank you! Joaquín M López Muñoz

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request for comments in a new format library
by Roberto Hinz 28 Feb '18

28 Feb '18

Dear boost community, some time ago I announced a format library I'm working on. I think at that time it was still too incipient for one to evaluate whether it looked promising, thought some few but very useful observation were made ( one regarding i18n and other code bloat ) that made me change many things. Now the library is more evolved and I think it will be ready for review somewhere in the second half of this year, if no big change happens. This is a c++14 text format library with some unique features: - designed to be utf8 friendly - easy to extend for new destination types ( like some different string type ) - able to align (justify) a set of sub-arguments as one ( see joins <https://robhz786.github.io/stringify/doc/html/special_input_types/special_i…> ) - it enables the use of translations tools ( like gettext ), yet the formatting is not specified by a format string. And the problem with format strings that they lead to run time errors (instead of compilation error ) when they are incorrect. Hence I much appreciate any comments, especially if can identify any flaw I didn't realize. repo: https://github.com/robhz786/stringify doc: https://robhz786.github.io/stringify/doc/html/ best regards roberto

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Re: [boost] [Boost-bugs] [Boost C++ Libraries] #13458: 'cl' is not recognized as an internal or external command, operable program or batch file. Failed to build Boost.Jam build engine. Please consult bjam.log for furter diagnostics.
by Andrew Depke 28 Feb '18

28 Feb '18

It looks like you're missing "cl.exe" on your system, or have not included it in your PATH. cl.exe, as seen here <https://msdn.microsoft.com/en-us/library/f35ctcxw.aspx>, is Microsoft's C++ compiler, which can be obtained by downloading the latest version of Visual Studio. Downloading and installing MSVS will automatically place it in your PATH. On Tue, Feb 27, 2018 at 2:28 PM, Boost C++ Libraries < noreply(a)lists.boost.org> wrote: > #13458: 'cl' is not recognized as an internal or external command, > operable program > or batch file. Failed to build Boost.Jam build engine. Please consult > bjam.log for furter diagnostics. > ------------------------------+--------------------- > Reporter: anonymous | Owner: (none) > Type: Bugs | Status: new > Milestone: To Be Determined | Component: None > Version: Boost 1.41.0 | Severity: Problem > Keywords: | > ------------------------------+--------------------- > 'cl' is not recognized as an internal or external command, > operable program or batch file. > > Failed to build Boost.Jam build engine. > Please consult bjam.log for furter diagnostics. > > -- > Ticket URL: <https://svn.boost.org/trac10/ticket/13458> > Boost C++ Libraries <http://www.boost.org/> > Boost provides free peer-reviewed portable C++ source libraries. > > _______________________________________________ > Boost-bugs mailing list > Boost-bugs(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-bugs > >

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[release] 1.67.0 closed for major changes
by Daniel James 28 Feb '18

28 Feb '18

The master branch is now closed for major changes and will be closed for the beta in a week. Also, you can also add your libraries' changes to the release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_67_0.q…> Remember that after editing the file, you need to submit the form to create a pull request. You can preview the release notes at: <http://www.boost.org/users/history/in_progress.html> Thanks, -- The Boost Release Team

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Boost managed_shared_memory not working with C's mmap call on freeBSD
by vijay sharma 27 Feb '18

27 Feb '18

Hi All, I am having two processes and they are sharing shared-memory. - Process-1 (implemented in c++ and using boost::interprocess::managed_shared_memory interface) - Process-2 (implemented in c and using "she_open" and "mmap" interfaces) This code was working fine on Linux But When I deployed same code on FreeBSD. Process-2 (C lang based) is keep on throwing error in mmap. Error is "Bad file Descriptor". Please let me know: 1. Do I need to change the interface while moving from Linux to FreeBSD. 2. Is there any known issue with this design. Code Snippet: Process-1(c++): obj = new boost::interprocess::managed_shared_memory( boost::interprocess::open_or_create,<shm_name>, <shm_size>); // to create shm obj->allocate(<data_size>) ; // to write in shm Process-2 (c): int fd = shm_open(<shm_name>,O_RDWR, 0666);void * startpoint = mmap(NULL, <shm_size>, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); // using the startpoint to read data written by process-1. Boost version: Boost.1.63.0 I have raised same on stackoverflow.com and below is the link: https://stackoverflow.com/questions/48984703/boost-managed-shared-memory-no… Thanks, Vijay

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[Boost][CMake] Status of cmake support.
by Mike 26 Feb '18

26 Feb '18

Hi everyone, since I couldn't find any official information about that, I wanted to ask if there is any new information about the cmake support in boost (since the initial discussion on the ml after the steering committee's announcement)? Is there some agreement on how to do the transition or at least a popular formal/informal proposal? Is there any place to track which libraries can already be built with cmake? What is the best way for a non library authors like me to help with the transition? IIRC there was talk about a cmake library some time ago, but I haven't heard anything about that in a long time. Is such a library even desired/necessary? Imho getting all of boost to compile with cmake should be pretty simple, but if this is expected to happen in a transparent manner (same output, same workflow including test result upload), a fair bit of boost knowledge, cmake skills and support machinery might be required. Best regards Mike

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[winapi] Bumping default target to Windows 7?
by Andrey Semashev 26 Feb '18

26 Feb '18

Hi, I was thinking about bumping the default target Windows version to 7 in Boost.WinAPI. The current default is Vista, which EOLed in April 2017. There is not much difference from the available API standpoint (in Boost.WinAPI this would enable a few constants related to process management), but there may be some interesting extensions that could be useful to libraries. Note that this will not preclude targeting older Windows versions, just as it doesn't preclude targeting XP or 2000 now. Users will still be able to specify the target Windows version as they can now. Note also that I'm not planning this for 1.67, only 1.68. Any objections/thoughts?

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[gsoc18] Project - Add statistics and machine learning functions
by Anagha G 26 Feb '18

26 Feb '18

Hi, I'm Anagha G. I'm pursuing 2nd year Bachelor of Engineering in Information Science and Engineering in R.V College of Engineering, Bangalore, India. I'm interested to work on a project to add statistics and machine learning functions to Boost.uBLAS. I've a good knowledge in Statistics, data visualization and Machine Learning. I've also learnt C++ and use it everyday for projects and academic assignments. Please let me know further details about finding a mentor and also how I should submit my competency test. Thanks Anagha G

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[system] [teeks99] Mass test failures on MSVC-14.0
by Andrey Semashev 26 Feb '18

26 Feb '18

Hi, Most of Boost.System tests are failing on the teeks99-09-f-win2016-64on64 tester, MSVC-14.0[1]. The test logs don't show any errors and I can't reproduce it locally. I'm seeing similar test failures in other libraries, like Boost.Atomic for example, and the links point to Boost.System. Is it possible to get the error log from the tester? [1]: http://www.boost.org/development/tests/develop/developer/system.html

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Re: [boost] [Boost][CMake] Status of cmake support.
by Mike 26 Feb '18

26 Feb '18

I don't believe in conspiracies. But I've seen enough resistance (me st of it well reasoned) on the ml after the steering committee made their announcement that I wouldn't be surprised if a lot of reviews focus on deficiencies / differences compared to boost build that are inherent to cmake and not the library itself.

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crash during bad_file_descriptor
by VIKRAM LODHI 26 Feb '18

26 Feb '18

Hi, Working Scenario: I have a scenario of single server and multiple client. server is constantly sending update to connected client. all the connection and transmission is async. Problem: lets say i have 3 client connected. which they are receiving update . if one client closed during in middle of transmitting. (killing the process of client ) my server crashes .. socket.async_write_some(buffer, [&](error_code& e, size_t size_) { if(e) { cout << e.message() << endl; } }); the last error i get is bad_file_descriptor . pfa : error thrown by gdb

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