February 2018 - Boost - lists.preview.boost.org

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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make makefile
by Ggh 26 Feb '18

26 Feb '18

Hello all, The past few days I have kept myself busy coding a kind of makefile generator. It can scan directories and generate makefile(s) from what c/c++ files it finds. Is such a program of interest to the boost lib? If so, I'd like to contribute. thank's Greg

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Re: [boost] [gsoc18]Boost.SafeFloat
by Rajat Miglani 25 Feb '18

25 Feb '18

I have read the paper "Goldberg, David. "What every computer scientist should know about floating-point arithmetic." ACM Computing Surveys (CSUR) 23.1 (1991): 5-48."and documentation and now having a little understanding of what this project is about.Presently going through the code and concepts, please guide me of what changes I have to do in the previous code to make it better. On Wed, Feb 21, 2018 at 11:52 PM, Damian Vicino <damian(a)vicino.com.ar> wrote: > Hi Rajat, > For the Boost.SafeFloat project, I suggest you take a look to the > following links: > - Repository: https://github.com/sdavtaker/safefloat > - Documentation: https://sdavtaker.github.io/safefloat/doc/html/index.html > > Also, try to read this paper if you didn't before: Goldberg, David. > "What every computer scientist should know about floating-point > arithmetic." ACM Computing Surveys (CSUR) 23.1 (1991): 5-48. > From the C++ perspective, key concepts you need to know are: > - Templates (a lot of it) > - Custom Literals > > A good proposal would be to take a read to the documentation and code base > and describe what is missing to complete the project. > Best regards, > Damian Vicino > > > > > 2018-02-21 14:11 GMT-03:00 Rajat Miglani via Boost <boost(a)lists.boost.org> > : > >> Dear boost community, >> I am a GSOC aspirant and I'd like to contribute to your organization. >> I have read the project ideas and is interested in working on:- >> 1)Boost.SafeFloat or >> 2)Enhancing Boost.Intrusive Library >> Can I get some more info about how to work on these projects and the basic >> requirements so that I can learn them and be able to contribute to my >> fullest. >> >> Thank you, >> >> _______________________________________________ >> Unsubscribe & other changes: http://lists.boost.org/mailman >> /listinfo.cgi/boost >> > >

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[gsoc18] Project - Add statistics and machine learning functions
by Anagha G 25 Feb '18

25 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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GSoC 2018
by shubham soni 25 Feb '18

25 Feb '18

Hello Boost Community! I'm Shubham Soni, fourth year dual degree student from IIT Kharagpur, India. I have experience in working with C/C++, Python, ruby and good theoretical knowledge in parallel programming. I've gone through the project list and found out* Boost.UBLAS (Add statistics & machine learning function)* to be interesting and i want to contribute in it. I have downloaded the code base and i am trying to understand it. Is there something else that i should read or anything you would suggest? Thanks *shubham soni*

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regarding gsoc 2018
by Akshay Raut 23 Feb '18

23 Feb '18

hello everyone i am from india doing bachelors in computer science. I am very passionate for c++ and hence, I want to contribute to it through this organization in this year's gsoc. can someone please tell me the best way to get started so that i get selected this year??

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[yap] Re-announcing Yap
by Zach Laine 23 Feb '18

23 Feb '18

I posted 2-3 months ago about Yap, an expression template library I've written that I intend to propose for Boost. This is just a reminder that the library exists, and where to find it. I'm giving a talk about it at C++Now 2017, and some time after that I intend to submit it to the queue. Louis Dionne has offered to serve as review manager when the time comes. You can find the main repo on GitHub: https://github.com/tzlaine/yap And online docs are here: https://tzlaine.github.io/yap Zach

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Query for interest in library: reflective enum
by Nir Friedman 23 Feb '18

23 Feb '18

Hello, I recently needed a reflective enum for work (that is an enum where you can programmatically convert to and from strings, know how many enumerators there are, and iterate over all enumerators). I looked online but I didn't find anything that met my requirements. I was surprised that there wasn't one in Boost. So I'd like to see if there is interest; I wrote an implementation that I think has several nice features. The most polished existing smart enum implementation I could find was http://aantron.github.io/better-enums/. However, the enum implemented there is not a true enum; it uses a nested member of a class kind of approach. So for example, the is_enum type trait will not recognize is as an enum. You cannot use it as a non-type template parameter. I strongly think that a good generic smart enum macro should generate the exact "vanilla" enum (or enum class) declaration. My library's syntax looks like this: WISE_ENUM(Foo, BAR, (BAZ, 3)) This generates, among other things, exactly: enum Foo { BAR, BAZ=3}; I intend this as an explicit guarantee of the library that the programmer can count on. That way when Foo is used for things unrelating to reflection, the developer can be confident that there will not be any surprises. Beyond compatability with C++ facilities for enums, and minimizing surprise, another advantage of this approach is that it's guaranteed to be backwards compatible. An existing codebase with an existing enum/enum class can switch to this smart enum with very high confidence that existing code will continue to work as before. The WISE_ENUM macro, beyond generating the vanilla enum, also generates a switch-case function for to-string conversion (for maximal efficiency), and finally it generates a constexpr function that returns a std::array<std::pair<const char*, Foo>> listing all of the arrays and their string descriptions. This constexpr function, which is found via ADL, allows writing a sequence of (constexpr) variables and functions providing the rest of the desired functionality. Usage looks like this: std::cerr << "My enum's size is : " << wise_enum::size<Foo> // this is constexpr template variable auto x = wise_enum::from_string<Foo>("BAR").value(); // from_string returns an optional auto y = wise_enum::to_string(x); // y is string literal, no heap allocation My implementation (POC level) is here: https://github.com/quicknir/wise_enum. I don't yet have separate macros to cover enum/enum class/explicit/implicit backing type combinations. It's only about 100 lines of code, leaning heavily on BOOST_PP to do the heavy lifting. It requires variadic macros, and can probably target C++11 (if it doesn't already). I probably need to "comma harden" the macros for bizarre stuff like WISE_ENUM(Foo, (BAR, my_func<3,4>())). It has the limitation that the macro cannot be used inside a class (this is hard to workaround for reflective macros). It's also unclear how repeated enumeration values would be handled (enum Foo { BAR = 1, BAZ = 1}). As it stands this will cause a compilation failure in the generated switch case of the to_string function. Can discuss more in subsequent emails. One suggested feature is an is_contiguous trait. Another reasonable bit of functionality might be an is_wise_enum trait. Version 2 of this library could target enum sets. Although it's not fancy, I think this nicely covers a piece of functionality I often need, and it does so avoiding any downside compared to using a simple enum (beyond having to use macros). Hope other people will agree! Cheers, Nir

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[Math] Only a fraction of the tests showing up online
by John Maddock 23 Feb '18

23 Feb '18

I assume this is an issue with the test matrix, but only about 1/3 of the Math lib tests are showing up at http://www.boost.org/development/tests/develop/developer/math.html Thanks, John. --- This email has been checked for viruses by AVG. http://www.avg.com

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[gsoc18] - Similarity Between Geometries and Timeframe Question
by Aidan Nyquist 23 Feb '18

23 Feb '18

Hello, My name is Aidan Nyquist, a sophomore at North Park University. I'm currently majoring in Math and Physics, and minoring in computer science. I have been programming for about 4 years now, and have experience with a fair amount of languages (Python, C/C++, Java, LISP, Haskell, SQL, etc.). Sifting through all the GSoC projects, while fun, can be somewhat difficult. I have just found the "Similarity between geometries" project and think I am a great fit. I wish I had found it sooner though, so I could have started the evaluation test done by now. Is there a rough deadline for its submission? I'm applying for one other organization, and they had a Feb. 28 deadline. If there is a similar date, I will reluctantly not attend the Hackathon I was hoping to go to this weekend. However, if there is some buffer time, that would be great to know, so I could be at ease. Any advice is always appreciated. Thanks, Aidan Nyquist

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