January 2020 - Boost - lists.boost.org

(no subject)
by anshu khare 17 Jan '20

17 Jan '20

I verified it when I ran Cout<<fixed<<setprecision(20) << cos(7*pi/2) << endl; The output of the above line came out to be -0.000 In the earlier code when the output came as -1. 06911e - 50, I thought it to be like (-50) + (-1. 06911e ) which seemed a highly negative value to me.

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Incorrect values of sin and cos
by anshu khare 17 Jan '20

17 Jan '20

cos(3*pi(cpp_bin_float_50>()/2)) does not give correct value. Only cos(pi(cpp_bin_float_50>()/2)) gives correct value. All odd multiples of cos(pi/2) do not give correct value. The issue with sin() as well. Anshu

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Future directions for Boost.Math and Boost.Multiprecision
by pbristow＠hetp.u-net.com 16 Jan '20

16 Jan '20

Trying to obtain some user (and potential user) feedback, and guidance on future work, a discussion at https://github.com/boostorg/math/issues/303 has been started. If you (or your friends and colleagues) have ideas for mathy things like 'special' functions, statistical distributions, tools like integration, curve fitting, signal processing ... that the current libraries do not meet, please feel free to contribute to this wish-list collection of ideas. (This is not, of course, a promise to implement everything or indeed anything! But might help us to focus work on areas that have most value to users.) Paul

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Worked on issue 49
by anshu khare 16 Jan '20

16 Jan '20

Hi I have worked on issue 49 of core library. Should I pull a request regarding the same?

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(no subject)
by anshu khare 16 Jan '20

16 Jan '20

cos(3*pi(cpp_bin_float_50>()/2)) does not give correct value.

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Contribution to core library
by anshu khare 13 Jan '20

13 Jan '20

Hello mentors, I would like to contribute to the core library of BOOST. I am working on windows. I cloned boostorg/core library. After cloning I found that there are many folders. Could you please tell which folder should I look up? Thank you Anshu Khare

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Documentation of dynamic cast
by anshu khare 11 Jan '20

11 Jan '20

Hello mentors, Could you please provide the documentation and code of dynamic_cast?

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[Astronomy] GSoC2020
by Pranam Lashkari 10 Jan '20

10 Jan '20

Hello, Earlier I was thinking of resting astronomy library for this GSoC and bring it to its first formal review after some development on my own cause it has been part of GSoC for 2 years now and still not reached to its first review and there are still many pending things before its first review. Since last month, I have started receiving many requests and ideas from the students about this library and many students are taking initiative and this may speed up the process of development. I still would like to know the opinion of the community before including this library in this GSoC. Thank you, Pranam Lashkari

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boost range for non integers
by Wim Leflere 10 Jan '20

10 Jan '20

Hello, I was wondering why the (i)range function is limited to integers. https://www.boost.org/doc/libs/1_72_0/libs/range/doc/html/range/reference/r… It would be nice if it also supported floats. Or any 'incrementable' class, e.g. Date. Regards, Wim Leflere

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New allocator uses global memory
by Frederick Gotham 10 Jan '20

10 Jan '20

I propose a new allocator that uses global (i.e. static duration) memory. Here's my current experimental code: #include <cstddef> /* size_t */ #include <new> /* Only for bad_alloc */ static int this_translation_unit; /* This serves the same purpose as __FILE__ */ template<typename T, std::size_t t_capacity, std::size_t t_counter, int *t_file = &this_translation_unit> class StaticAllocator { protected: static T buf[t_capacity]; public: typedef T value_type; template<typename U> struct rebind { typedef StaticAllocator<U, t_capacity, t_counter, t_file> other; }; T *allocate(std::size_t const n) { if (n > t_capacity) throw std::bad_alloc(); return buf; } void deallocate(T *, std::size_t) { /* Do Nothing */ } }; template<typename T, std::size_t t_capacity, std::size_t t_counter, int *t_file> T StaticAllocator<T, t_capacity, t_counter, t_file>::buf[t_capacity]; using std::size_t; #include <vector> using std::vector; #include <iostream> using std::cout; using std::endl; auto main(void) -> int { vector< char, StaticAllocator< char, 4, __COUNTER__ > > v; v.push_back('a'); v.push_back('b'); v.push_back('c'); v.push_back('d'); for (auto const &elem : v) cout << elem << endl; vector< char, StaticAllocator< char, 4, __COUNTER__ > > v2; v2.push_back('x'); v2.push_back('y'); v2.push_back('z'); for (auto const &elem : v2) cout << elem << endl; // Now try the first vector again for (auto const &elem : v) cout << elem << endl; } The trick I am using with "this_translation_unit" works fine on GNU and Clang, however it fails to compile on Microsoft because the variable has internal linkage. I'm sure we can do this another way using something from the Boost preprocessor library. The preprocessor macro __COUNTER__ is available on every compiler I know of. Frederick P.S. This is my second idea posted to the Boost dev list. My first one was "istream_iterator_limited".

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Willing to participate in GSOC'20 with boost
by soham mukherjee 10 Jan '20

10 Jan '20

Hi, I am Soham Mukherjee. I am willing to participate in GSOC-20 and was looking forward participating with this organization. Can someone please guide me on how to get started and linking me to some easy fixes and also documentations so that I can familiarize myself with the codebase. Thanks

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Clone warnings in lexical_cast
by Tom Kent 09 Jan '20

09 Jan '20

I just ran a: git clone --recursive https://github.com/boostorg/boost boost_root and I got some warnings in lexical_cast: Cloning into 'D:/teeks99-09/boost_root/libs/lambda'... Cloning into 'D:/teeks99-09/boost_root/libs/lexical_cast'... warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/b1/102161720ea50668a5756828409400a4314744.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/8a/0a6c194259a9a3fa24ea3fb815899bfcbfed64.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/47/dd68ef6ee5c02257a57d03ac9e611a68893d0d.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/02/b86ef5bcc4574e5c03b75ed463dbb5ada446c9.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/c2/b4875ef060ea7de75feceb1f20284766128325.temp': Invalid argument Cloning into 'D:/teeks99-09/boost_root/libs/local_function'... I don't think these are an issue necessarily but it might be something that can be cleaned up. Tom

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[Graph] Large incoming changes to Boost.Graph master.
by John Maddock 08 Jan '20

08 Jan '20

Dear all, Boost.Graph has had no maintainer for some time, but the CMT has been busy fixing bugs none the less. Unfortunately, other than some trivial fixes to docs and some directory refactoring, nothing much has been merged to master in a good while . On the plus side, develop is now in a better tested tested state than IMO it has ever been, however the change set is rather large so the potential to mess up somebodies code is certainly there: https://github.com/boostorg/graph/pull/196. So... this is both a heads up, and a plea: if you have any mission critical code using the Graph library, could you please test against current develop and report any problems? If you don't want to mess about with git, download from https://github.com/boostorg/graph/archive/develop.zip and place zipfile-contents/libs/graph/include in your include path ahead of that for Boost-1.72. Many thanks, John.

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What happened to Boost.Nowide?
by Alexander Grund 08 Jan '20

08 Jan '20

Hi, I'm a user of (a fork of) Boost.Nowide and already fixed some issues I found and was looking into getting them upstream. I also wanted to know, if it is finally in Boost. Unfortunately this does not seem to be the case. I found https://lists.boost.org/Archives/boost//2017/06/236475.php which accepted it into Boost. This is from mid-2017 and nothing has happened since. Does anyone know what the status of Boost.Nowide is? It seems the filestream parts are now incorporated into Boost.FileSystem. So it seems only cin/cout/cerr, the args wrapper and the C-functions (fopen, ...) are missing. Especially the first 2 are very useful in writing cross-platform code. Might those be integrated into some other Boost Library? Thanks, Alex

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Retirement as Review Wizard
by Ronald Garcia 07 Jan '20

07 Jan '20

Dear Boosters and Boost Steering Committee, After roughly 14 years as a Boost Co-Review Wizard, I feel that the time has come for me to step down from the position, and make room for a new face with fresh ideas. It has been my pleasure to serve in this position for this time alongside first Tom Brinkman and now John Phillips. I look forward to seeing what the next 14+ years of Boost brings! Sincerely, Ron Garcia Boost Co-Review Wizard

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Query on Project Multiprecision/Math GSoC 2020
by Christopher Kormanyos 06 Jan '20

06 Jan '20

Dear Boost Is there a place to post and describe a potentialGSoC 2020 project? We have a potential project for GSoC 2020. It involvessignificantly extending the precision of Boost.Multiprecisionand harmonizing these extensions and tests with Boost.Math.I have the proposal worked out in plain text and would liketo post it or share it. We have discussed this project (in PM) with the knownrecent authors and maintainers of Multiprecision and Math,and interest is strong. On a personal note, my name isChristopher Kormanyos, previous three-time Boost GSoCmentor. In previous years, I have also contributed to bothMath and Multiprecision. Thank you and kind regards, Chris

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Re: [boost] Recommended way of generating documentation
by pbristow＠hetp.u-net.com 06 Jan '20

06 Jan '20

> -----Original Message----- > From: Boost <boost-bounces(a)lists.boost.org> On Behalf Of Richard Hodges via > Boost > Sent: 1 January 2020 12:03 > To: boost(a)lists.boost.org List <boost(a)lists.boost.org> > Cc: Richard Hodges <hodges.r(a)gmail.com> > Subject: Re: [boost] Recomended way of generating documentation > > Treading carefully here as I'm new to boost library maintenance... > > > So that you can cross-reference the Doxygen reference with whatever > > other > documentation you have > > http://www.doxygen.nl/manual/autolink.html suggests that links to external URLs > are recognised by doxygen. Presumably linking to the correct place vis-a-vis > release/developer builds can be controlled with a macro in a generated Doxyfile? > > > And it's Doxygen to XML, XML to Boostbook. Then of course Boostbook to > Docbook, and Docbook to HTML. > > Other than the very pleasing boost documentation styling, is this seemingly > convoluted conversion route necessary? Is it not possible to configure a Doxyfile to > contain the correct styling? > > I have no knowledge of the evolution of boost documentation and have no axe to > grind, but as a newcomer it seems to me that there is a lot of 'unnecessary' > compication in the production of documentation. I appreaciate that there's no real > sense in revisting existing libraries, but for new ones wouldn't it be prudent to > choose the shortest possible path which involves the least learning and > maintenance? It depends on the size of the documentation. For 'trivial' documentation, the Doxygen and Markdown combination is acceptable, but I believe strongly that the best Boost documentation is done using the Quickbook toolchain (including Doxygen syntax comments to provide a references section). A killer feature of Quickbook is the ability to include code snippets from actual C++ examples that can be run, ensuring that what you get is what compiles and runs. As a mark-up language Quickbook is pretty obvious (apart from the gotcha of using indent-spaces as a way to add code sections - a common but quick'n'dirty markup feature that can cause some confusion). Paul

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Boost ASIO
by live man 03 Jan '20

03 Jan '20

Hi, We have been using Boost for our firmware product which runs in ARM processor. However for development we make use of Visual Studio IDE. We also have our own TCP / IP suite which defines its own socket.h file. We are facing issue related to using Boost ASIO in Windows development platform. It seems that the library by default includes windows networking header files - which we do not want. Instead we want Boost ASIO to make our own library socket headers and declaration. We noticed that if we include Boost ASIO and our TCP / IP socket declaration we get re-definition error and compilation fails with lots of errors? Please let us know how we can resolve the issue with the objective mentioned above? Thanks in advance. Regards, Prakash

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Google Summer of Codes 2020
by saloni garg 02 Jan '20

02 Jan '20

Hello, My name is Saloni Garg. I am an undergraduate student of B.tech in computer engineering. Currently, I am in my second year and I am looking forward to participate in this year's Google Summer of code 2020. So, I want to know, if Boost organization is planning to be a part of this year's Google Summer of codes 2020? Thank you! Saloni Garg

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Recomended way of generating documentation
by Alexander Grund 01 Jan '20

01 Jan '20

Hi, I'm currently in the process of generating documentation in a Boost usable format and got a couple questions. The documentation is currently in-source in Doxygen format and has a markdown file for the start page. 1. Which aliases do I need and for what? I've seen boostdoc and boostrelease but couldn't find a description what and why they are 2. Where do the documentation files need to go? It seems using BJam naively outputs them to bin.v2 not to the libraries doc folder which I'd even see useful because generated files should not clobber the source tree 3. What benefit is there going from Doxygen (over multiple conversions) to boostbook? Can't I just go from Doxygen to HTML? 4. If the above: Calling `doxygen mylib.html` in BJam generates a mylib folder and a mylib.html redirecting into that folder. Both hardcoded to go into a subfolder of bin.v2. How is that useful/useable? Wouldn't I want a 'html' folder and an index.html redirecting to the index.html contained or no redirection file at all? 5. As I'm thinking about calling doxygen manually: Do I need to do anything so e.g. mylib shows up in boost/doc/html? Why is only a subset of the libraries there? Thanks for any help or pointers! Alexander Grund

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